prsona itnss ainrr utritiona ciaist - u.s. career...

Personal Fitness Trainer & Nutritional Specialist

Explore the possibilities

Instruction Pack 2 Lessons 6-10

0203401LB02B-74

Instruction Pack 2


Lesson 6: Fueling for ActivityLesson 7: The Energy EquationLesson 8: Anatomical Terms and

LocationsLesson 9: Musculoskeletal Anatomy

and PhysiologyLesson 10: Muscles in Action I

No part of this document may be reproduced or transmitted in any form or by any means, electronic or mechanical, for any purpose, without the express written permission of U.S. Career Institute.

Copyright © 2013-2014, Weston Distance Learning, Inc. All Rights Reserved. 0203401LB02B-74

AcknowledgmentsAuthorsMarion Agnew, M.S.Carly Burkhart, B.S.Editorial StaffTrish Bowen, M.EdKaty Little, M.S.Stephanie MacLeod, M.SElizabeth Munson, Ph.D.Sue Schildge, B.S.Kimberly Fields, M.A.Leslie Ballentine, M.S.

Design/LayoutConnie HunsaderSandy PetersenD. Brent Hauseman

U.S. Career InstituteFort Collins, CO 80525

www.uscareerinstitute.edu

Table of Contents

Lesson 6: Fueling for ActivityStep 1: Learning Objectives for Lesson 6...................................................................................................................... 1Step 2: Lesson Preview .................................................................................................................................................... 1Step 3: What Is Good Fitness Nutrition? ...................................................................................................................... 2

Dietary Rules for Training ............................................................................................................................... 2Step 4: Fueling for Fitness Goals ................................................................................................................................... 3

Building Muscle Mass ...................................................................................................................................... 3Increasing Muscle Endurance ......................................................................................................................... 4Reducing Fat Mass ............................................................................................................................................ 5Foods to Improve Health ................................................................................................................................. 5

Step 5: Practice Exercise 6-1 ........................................................................................................................................... 6Step 6: Review Practice Exercise 6-1 ............................................................................................................................. 7Step 7: Protein Power ...................................................................................................................................................... 7

Types of Protein ................................................................................................................................................ 8The Foundation of Muscle .............................................................................................................................. 8Winning Combinations ................................................................................................................................... 8How Much is Right for You? ........................................................................................................................... 9

Step 8: Carbohydrates: Fuel for the Body ..................................................................................................................... 9Types of Carbohydrates ................................................................................................................................... 9Metabolic Fuel: Aerobic versus Anaerobic .................................................................................................. 10The Effect of Carbohydrate on Muscle Growth ......................................................................................... 11The Low-carbohydrate Trend ....................................................................................................................... 11The Interaction of Proteins and Carbohydrates ......................................................................................... 12

Step 9: Amino Acids Affect Muscle Function............................................................................................................ 12The Essential Amino Acids ........................................................................................................................... 12Nitrogen Balance ............................................................................................................................................ 12

Step 10: The Role of Lipids in the Body ..................................................................................................................... 13Step 11: Practice Exercise 6-2 ...................................................................................................................................... 14Step 12: Review Practice Exercise 6-2 ......................................................................................................................... 15

0203401LB02B-74 III

Step 13: Supplements .................................................................................................................................................... 15The Importance of Iron ................................................................................................................................. 15Increasing Calcium Intake ............................................................................................................................. 16Some People have Special Needs .................................................................................................................. 16Athletes and Supplements ............................................................................................................................. 16

Step 14: Fueling to Recover from Illness or Injury ................................................................................................... 17Eating Well To Get and Stay Healthy ........................................................................................................... 17

Step 15: Steroids ............................................................................................................................................................. 18How Do Steroids Work? ................................................................................................................................ 18Steroids and Performance .............................................................................................................................. 19Dangers of Steroid Use ................................................................................................................................... 19

Step 16: State of Mind .................................................................................................................................................. 20Mind Over Matter .......................................................................................................................................... 20

Step 17: Practice Exercise 6-3 ...................................................................................................................................... 21Step 18: Review Practice Exercise 6-3 ......................................................................................................................... 22Step 19: Lesson Summary ............................................................................................................................................. 22Step 20: Quiz 6 ............................................................................................................................................................... 22

Lesson 7: The Energy EquationStep 1: Learning Objectives for Lesson 7...................................................................................................................... 1Step 2: Lesson Preview .................................................................................................................................................... 1Step 3: It All Begins with Oxygen .................................................................................................................................. 2

Gas Exchange .................................................................................................................................................... 2Respiratory Physiology .................................................................................................................................... 3Putting It All Together: Normal Oxygen Delivery ....................................................................................... 5Imbalance in Oxygen Exchange ..................................................................................................................... 5

Step 4: Blood Moves the Oxygen ................................................................................................................................... 8Blood in Motion................................................................................................................................................ 8Cardiac Physiology ........................................................................................................................................... 9Moving Faster: The Exercising Heart ............................................................................................................ 9

Step 5: Practice Exercise 7-1 ......................................................................................................................................... 10Step 6: Review Practice Exercise 7-1 ........................................................................................................................... 11Step 7: Guidelines for Cardiovascular Activity .......................................................................................................... 11

Types of Aerobic Activities ............................................................................................................................ 12Frequency ........................................................................................................................................................ 15

IV 0203401LB02B-74


Duration ........................................................................................................................................................... 15Intensity ........................................................................................................................................................... 16FITT Principle................................................................................................................................................. 16

Step 8: Warm Up and Cool Down ............................................................................................................................... 17Warm Up How-tos ......................................................................................................................................... 17Cool Your Jets .................................................................................................................................................. 18

Step 9: Physiology of Energy Production ................................................................................................................... 18Energy Requirements ..................................................................................................................................... 18ATP: Energy’s Building Block ....................................................................................................................... 19Using Energy: How Do Muscles Do It? ....................................................................................................... 19Using Fats, Carbohydrates and Proteins ...................................................................................................... 20

Step 10: The Importance of Anaerobic Threshold, Glycogen and Creatine Phosphate ...................................... 20Step 11: Practice Exercise 7-2 ...................................................................................................................................... 21Step 12: Review Practice Exercise 7-2 ......................................................................................................................... 22Step 13: Lesson Summary ............................................................................................................................................. 22Step 14: Quiz 7 ............................................................................................................................................................... 23

Lesson 8: Anatomical Terms and LocationsStep 1: Learning Objectives for Lesson 8...................................................................................................................... 1Step 2: Lesson Preview ................................................................................................................................................... 1Step 3: What Is Human Biology? ................................................................................................................................... 1

Anatomy ............................................................................................................................................................ 2Step 4: Pathology ............................................................................................................................................................. 3Step 5: Practice Exercise 8-1 ........................................................................................................................................... 4Step 6: Review Practice Exercise 8-1 ............................................................................................................................. 4Step 7: The Anatomical Position ................................................................................................................................... 4Step 8: Planes and Sections of the Human Body ........................................................................................................ 5

Transverse Sections and the Transverse Plane .............................................................................................. 6Sagittal Sections and the Sagittal Plane.......................................................................................................... 7Coronal Sections and the Coronal Plane ....................................................................................................... 7

Step : Practice Exercise 8-2 ............................................................................................................................................. 9Step 10: Review Practice Exercise 8-2 ........................................................................................................................... 9Step 11: Anatomical Parts and Locations ..................................................................................................................... 9Step 12: Practice Exercise 8-3 ...................................................................................................................................... 14Step 13: Review Practice Exercise 8-3 ......................................................................................................................... 14

0203401LB02B-74 V

Table of Contents

Step 14: Joints and Connective Tissues ...................................................................................................................... 15Synovial Joint Classifications ........................................................................................................................ 16Connective Tissues ......................................................................................................................................... 17

Step 15: Movements of the Body ................................................................................................................................. 18Range of Motion or ROM .............................................................................................................................. 19Classifications of Movements ....................................................................................................................... 19


Just for Fun ...................................................................................................................................................... 23

Lesson 9: Musculoskeletal Anatomy and PhysiologyStep 1: Learning Objectives for Lesson 9...................................................................................................................... 1Step 2: Lesson Preview .................................................................................................................................................... 1Step 3: The Skeletal System ............................................................................................................................................ 2

Bone Tissue ....................................................................................................................................................... 2Parts of the Skeletal System ............................................................................................................................. 3Skeletal Physiology ........................................................................................................................................... 5Bones of the Axial and Appendicular Skeleton ........................................................................................... 5

Step 4: Practice Exercise 9-1 ........................................................................................................................................... 7Step 5: Review Practice Exercise 9-1 ............................................................................................................................. 8Step 6: The Muscular System ......................................................................................................................................... 8

Muscle Physiology ............................................................................................................................................ 8Location, Location, Location ........................................................................................................................ 13

Step 7: Practice Exercise 9-2 ......................................................................................................................................... 13Step 8: Review Practice Exercise 9-2 ........................................................................................................................... 15Step 9: How Do the Skeletal and Muscular Systems Work Together? .................................................................... 15

Movement and the Musculoskeletal System ............................................................................................... 15Strength Factors and the Musculoskeletal System ..................................................................................... 16

Step 10: Real-world Applications ................................................................................................................................ 16Muscle Fiber Types ......................................................................................................................................... 16Training Load and Repetitions ..................................................................................................................... 17Basic Resistance Training Guidelines .......................................................................................................... 18Strength Plateaus ............................................................................................................................................ 18

VI 0203401LB02B-74



Lesson 10: Muscles in Action IStep 1: Learning Objectives for Lesson 10 ................................................................................................................... 1Step 2: Lesson Preview .................................................................................................................................................... 1Step 3: Muscle Nutrition ................................................................................................................................................. 2

Building Strong Muscles .................................................................................................................................. 2Going the Distance ........................................................................................................................................... 3The Body at Rest ............................................................................................................................................... 3Supplementing the Diet ................................................................................................................................... 3

Step 4: Muscle Fibers and Connective Tissues ............................................................................................................ 4Muscle Fibers .................................................................................................................................................... 4Connective Tissues ........................................................................................................................................... 5

Step 5: The Nervous System .......................................................................................................................................... 6Step 6: Strength Training in Practice ............................................................................................................................ 6

Muscle Movement ............................................................................................................................................ 6Exercising Muscles ........................................................................................................................................... 7

Step 7: Examples of Isometric Exercises ....................................................................................................................... 9Step 8: Examples of Isotonic or Dynamic Resistance Exercises ................................................................................ 9Step 9: Muscle Soreness and Fatigue ........................................................................................................................... 10Step 10: Practice Exercise 10-1 .................................................................................................................................... 11Step 11: Review Practice Exercise 10-1 ....................................................................................................................... 12Step 12: Lesson Summary ............................................................................................................................................. 13Step 13: Quiz 10 ............................................................................................................................................................. 13

Answer KeyLesson 6 ............................................................................................................................................................................ 1

Practice Exercise 6-1 ........................................................................................................................................ 1Practice Exercise 6-2 ........................................................................................................................................ 1Practice Exercise 6-3 ........................................................................................................................................ 2

Lesson 7 ............................................................................................................................................................................ 3Practice Exercise 7-1 ........................................................................................................................................ 3Practice Exercise 7-2 ........................................................................................................................................ 3

0203401LB02B-74 VII

Table of Contents

Lesson 8 ............................................................................................................................................................................ 4Practice Exercise 8-1 ........................................................................................................................................ 4Practice Exercise 8-2 ........................................................................................................................................ 4Practice Exercise 8-3 ........................................................................................................................................ 5Practice Exercise 8-4 ........................................................................................................................................ 5

Lesson 9 ............................................................................................................................................................................ 6Practice Exercise 9-1 ........................................................................................................................................ 6Practice Exercise 9-2 ........................................................................................................................................ 6Practice Exercise 9-3 ........................................................................................................................................ 7

Lesson 10 .......................................................................................................................................................................... 8Practice Exercise 10-1 ...................................................................................................................................... 8

VIII 0203401LB02B-74


Lesson 6Fueling for Activity

Step 1: Learning Objectives for Lesson 6When you have completed the instruction in this lesson, you will be trained to:

● Determine the fuels needed to increase muscle mass and endurance and reduce fat mass.

● Explain the sources and impact of protein and carbohydrates on the body’s muscle function.

● Describe amino acids and lipids.

● Discuss supplements and steroids.

● Explain how certain fuels aid the body’s immune system and recovery from illness or injury.

● Explain the connection between mind and body in athletic performance.

Step 2: Lesson PreviewJessie is 30 years old and the mother of two young children. Her previous attempts at shedding excess weight and getting into shape following pregnancy were derailed because she was unable to stay with an exercise program long enough to see results. Jessie has hired Carrie, a personal fitness trainer and nutritional specialist, to help her address some of the factors that prevent her from regaining the level of fitness she enjoyed before having children.

During her initial interview, Jessie tells Carrie that her attempts at low-carbohydrate dieting left her feeling too fatigued for regular daily activity, let alone physical workouts. Jessie also believes that lifting weights would bulk her up, keeping her from achieving her goal of slimming down.

Carrie explains to Jessie the importance of building muscle tissue when it comes to shaping the body and losing excess fat. She also helps Jessie do an overhaul of her dietary habits. Carrie shows her the right foods to eat to build muscle mass and fuel muscle endurance. Along with a new diet plan, Carrie recommends some supplements that will support Jessie’s health and fitness goals.

Jessie feels a bit apprehensive about some of Carrie’s suggestions—such as the idea of eating more carbohydrates and lifting weights to slim down. Carrie patiently answers all of Jessie’s questions, working to establish trust and eliminate many of her client’s concerns. At the end of their discussion, Jessie decides to embark on the suggested fitness and diet plan with Carrie as her guide. Jessie is an excellent example of how important it is to properly fuel the body for exercise. We’ll revisit Jessie’s story throughout this lesson to see how her dietary changes affect her fitness success.

0203401LB02B-06-74


6-2

In this lesson, you will learn how to fuel the body for a variety of fitness goals. You’ll also examine the role that proteins, carbohydrates and amino acids all play in muscle function, as well as how supplements can aid in the achievement of fitness goals. Finally, you’ll learn about steroid use and how a client’s psychological state affects his physical performance.

Some of what you learn in this lesson will be a review of what you’ve read in previous lessons; however, you’ll also be getting a little more information. Remember that everything these lessons offer will be important in your new career as a personal fitness trainer and nutritional specialist. The knowledge base you receive in this course will prove to clients that you are dedicated to helping them succeed. And once you are established in your role, more clients—and more income—will come your way! So, let’s continue on this career path and start the lesson.

Step 3: What Is Good Fitness Nutrition?You know from your previous lessons that not all foods are created equal. The various substances that make up the foods we eat can have potent influences on the body and mind. For those involved in a fitness plan or training for an athletic event, the importance of food quality and quantity is even greater. Good nutrition, through a diet providing all the energy nutrients, vitamins, minerals and water the body requires, is necessary to reach both performance and appearance goals. While each person’s nutritional needs vary according to genetic makeup, lifestyle and training program, there are certain rules regarding dietary programs that apply to and benefit all people, regardless of individual fitness goals.

Dietary Rules for TrainingThe first step a person can take to get the most out of his training program is to eat at least five times a day. This means a person should have at least three small meals and two snacks spaced throughout the day. Eating frequently helps keep both blood sugar and insulin levels stable. These are two important factors in determining a person’s overall energy level. A body that receives food every few hours has the resources to repair itself and restock its energy stores. Eating infrequently causes the body to go into famine mode, meaning it stores the food a person eats as body fat for fear that it is being starved.

A second rule to follow involves dietary proportions of the three macronutrients. The macronutrients are carbohydrates, fat and protein. You probably recall learning about these three food components in a previous lesson. A balanced meal or snack generally contains one part fat, two parts protein and three parts carbohydrates. If Jessie plans to work out within the hours following a meal or snack, she will need to increase the amount of carbohydrates she eats to meet her increased energy demands. Likewise, if she plans to rest following a meal, she should decrease the carbohydrates she eats.

A third rule addresses dietary needs and weight control. To lose fat, a person must consume fewer calories than she expends, which you learned in Lesson 5. On the other hand, gaining muscle requires a person to take in more calories than necessary to maintain her current body weight.

So, what happens when a person’s goal is to shed excess body fat while also gaining muscle? The answer lies in following both energy equations but on different days. This might mean eating slightly more calories than necessary two days a week, and then eating slightly fewer calories the remaining five days. Eating the excess calories on days of heavy training ensures that the extra fuel goes toward building new muscle.

0203401LB02B-06-74

Fueling for Activity

6-3

You know that sometimes the need arises for a person to use supplements to meet all the body’s nutritional requirements. The lack of nutrients in many of the foods we eat—along with the increased demands placed on the body and the reduced caloric intake typical of some training programs—contributes to this need. Determining where a person’s diet may be deficient and using supplements to meet these needs can improve endurance and speed up recovery time between workouts. This allows the client to reach her fitness goals more quickly. For example, Carrie recommends that Jessie take a protein supplement to ensure that Jessie’s muscles recover from the new weight-lifting program. We will talk about supplements in a more in-depth manner later in this lesson.

A final point to consider when creating any dietary plan is the importance of personal taste. Finding foods that meet a client’s nutritional needs while satisfying her taste buds is tricky but necessary. Most foods, even if only in small amounts, can fit into a balanced diet. When it comes to eating one’s favorite—and perhaps not so healthy—foods, moderation is the key. This makes people less likely to have a dietary slip-up. Dietary lapses do happen, but it’s important to remind clients that when it comes to leading a life based on wellness, progress—not perfection—is the main goal.

Step 4: Fueling for Fitness GoalsNow, let’s take a closer look at what one would eat to increase muscle mass and endurance while reducing fat mass.

Building Muscle MassYou’ve got to eat to lose body fat. Say that again? This statement often seems crazy to people like Jessie, who are new to the world of fitness. But this idea holds true, because muscle needs calories to grow, and muscles burn more calories than fat. A client who isn’t building muscle despite consistent weightlifting probably isn’t eating enough calories to fuel muscle growth. Teaching clients to use high-calorie foods to supply the needed fuel for muscle growth is helpful, especially for clients who have difficulty finding the time or desire to consume these needed calories. Examples of nutritious high-calorie foods include nuts, dried fruits, peanut butter and smoothies made with soy or protein powder.

When exercising to build muscle mass it is important to eat enough quality protein. A high-quality or complete protein supplies all the essential amino acids in the ratios that the human body requires to build muscle tissue. A protein source that is deficient in one or more of the essential amino acids is a low-quality or incomplete protein. Do you remember reading about complete and incomplete proteins in the previous lesson?

You’ve already learned that protein sources contain molecules called amino acids. Let’s review a bit of information about these molecules. The protein the human body needs to build and repair tissue is made up of 20 different amino acids. Eleven of these amino acids are called nonessential because the body makes enough of them on its own. So their consumption isn’t necessary. The remaining nine amino acids are essential, meaning they must be provided to the body through dietary sources.

0203401LB02B-06-74


6-4

Consuming an adequate amount of carbohydrates is also an important aspect of building muscle mass. This is because carbohydrates provide the energy necessary to fuel a workout session. If the body runs out of stored carbohydrates during an exercise session, it starts to burn protein, and this hinders muscle growth. Remember that complex carbohydrates, such as whole grain breads, high fiber cereals, brown rice and whole wheat pasta, digest slowly and provide a sustained source of energy, while simple carbohydrates, such as fruits and fruit juices, require little digestion and provide a quick source of energy.

Eating a snack that contains both protein and carbohydrates just prior to a weightlifting session provides the body with a fuel source. This also helps the muscles recover faster following the workout. Some examples of snacks that provide both protein and carbohydrates include a cup of fruit-flavored yogurt, a bowl of bran cereal with milk or peanut butter on toast.

Many people like to work out in the morning and often do so on an empty stomach. These people fail to recognize their body’s need for fuel. This is where you, the personal fitness trainer and nutritional specialist, come in. A client, like Jessie, must understand that eating less will not help her attain her fitness goals any faster. In fact, it only will hinder her exercise program.

Increasing Muscle EnduranceMuscle endurance is the ability of the muscles to sustain physical exercise efforts for a period of time. Muscle endurance comes into play during both cardiovascular exercise and strength-training workouts. What a person eats and drinks prior to exercising has a direct impact on muscle endurance, as well as overall performance during the workout.

During exercise, a substance called glycogen, which is made from the carbohydrates a person eats, fuels muscles. It is important to have adequate glycogen stored in the body to support muscular endurance during workouts. Once glycogen stores are depleted, the muscles begin to use sugar in the blood as fuel. As a person’s blood sugar level drops, he will begin to feel tired and may need to stop the workout. To keep glycogen stores up, eating a diet rich in foods, such as breads, cereals and other grains, is recommended. Grains also contain several key B vitamins needed to convert carbohydrates into an energy form that the muscles can readily use.

Eating enough fruits and vegetables plays an important role in increasing muscle endurance. When a person exercises, he breathes harder, taking in more oxygen than he would when he is simply sitting. Once inside the body, oxygen tends to become unstable, damaging muscle cells and resulting in muscle inflammation and soreness. Fruits and vegetables provide substances called antioxidants that help repair damaged cells. This helps prevent muscle soreness and enables a person to continue exercising.

Believe it or not, the primary component of muscle tissue is water. So drinking enough fluids before, during and after workouts has a big impact on muscle endurance. Since the early signs of dehydration often go unnoticed, staying on a regular hydration schedule is vital. This ensures adequate fluid intake for both peak muscle performance and overall health.

0203401LB02B-06-74


6-5

Reducing Fat MassWhen a person’s fitness goal is fat loss, it is often necessary for her to make changes in her diet to achieve her goal most efficiently. Calorie reduction, when done incorrectly, can result in nutrient deficiencies and fatigue, making it essential that the client is educated regarding healthy weight-loss practices. Think back to Jessie’s statement to Carrie about how low-carbohydrate diets left her feeling tired. Jessie’s body simply wasn’t getting what it needed to give her energy.

But eating fewer calories doesn’t have to leave a person feeling weak or hungry. There are several tricks of the trade that help people reduce their caloric intake while still feeling full and maintaining their energy level. First, as a personal trainer and nutritional specialist, encourage clients to choose foods that have a low caloric density, such as fruits, vegetables and broth-based soups. The stomach feels full based on the volume of food consumed instead of the number of calories consumed. Therefore, a person feels fuller after eating a large salad containing less than 100 calories than she would after indulging in a 400-calorie piece of cheesecake.

Foods that contain a high percentage of water or fiber help people feel fuller longer, too. Fiber-rich cereals, beans and fruit all fool the body into feeling like it has consumed more calories than it has. Choosing low- or non-fat dairy products also helps cut down the number of calories a person consumes.

Eating smaller, more frequent meals is another way to keep from feeling tired or hungry when cutting calories. Grazing throughout the day regulates the hormones that affect hunger level. Consuming a high-protein meal or snack also staves off hunger pangs longer because it slows down digestion. Ensuring that a person who is cutting calories is receiving adequate amounts of essential nutrients is important. Choosing a variety of nutrient-dense foods, such as fruits, vegetables and lean meats, as well as taking a multivitamin, helps guard against deficiencies.

The goal of any weight loss program should be to lose fat mass while preserving or building as much lean muscle mass as possible. Gradual weight loss helps preserve lean muscle, and losing no more than one to two pounds of body weight a week is considered healthy. Rapid weight loss tends to be the result of a loss of muscle and water, and this should be avoided. Finally, when it comes to weight loss and body composition, each person is different. One person may feel and perform best at a very low body-fat percentage, while another person may require a higher body-fat percentage to perform at her best. Likewise, the optimal diet for one person varies considerably from the diet of another person.

Foods to Improve HealthModern science gives us the ability to study the impact of certain foods on a person’s health. In some cases, the health benefits a food provides can be attributed to a particular component of that food, such as a vitamin, mineral or antioxidant. In other cases it may be the unique combination of nutrition that a given food provides or an unknown component that makes the food exhibit healing or preventive qualities. When adopting a healthier lifestyle, eating foods known to improve one’s health compliments a fitness program and ensures optimal results.

Fruits and vegetables are nutritional powerhouses. The vitamins, minerals and antioxidants they provide help repair muscles following a workout. For example, spinach contains carotenes that protect muscles from damage when you exercise extra hard. This leafy, green vegetable also contains calcium for strong bones and iron that increases energy level. Adding spinach to salads is one way to add more spinach to your diet.

0203401LB02B-06-74


6-6

Citrus fruits, such as oranges, also provide a wide range of benefits to the exerciser. The Vitamin C in citrus fruits leads to faster muscle recovery and a stronger immune system, and the folic acid helps build the red blood cells needed to carry oxygen throughout the body.

Garlic and onions contain phytochemicals that help unclog arteries and prevent blood clots from forming. This makes them excellent dietary choices for people with high cholesterol or heart disease. The fiber contained in many berries—including strawberries—helps soak up and remove cholesterol byproducts from the body, while a phytochemical in tomatoes prevents bad LDL cholesterol from building up in the arteries. The goal is to avoid atherosclerosis, or the formation of plague along blood vessel walls from the build-up of LDL.

Another nutrient-rich food is the soybean—the only non-animal source of complete protein. Soy contains a phytochemical that protects against osteoporosis and heart disease.

Flaxseed and salmon are two foods that contain omega-3 fatty acids. These fats are known to lower LDL cholesterol levels. Nuts are packed with heart-healthy monounsaturated fats, Vitamin E to reduce muscle damage and a number of minerals that each provides its own health benefits.

Modern research has also uncovered health benefits from consuming food, such as chocolate and wine—neither of which traditionally were considered health foods. Drinking one to two glasses of wine with meals each day raises HDL cholesterol levels, and red wine contains phytochemicals that prevent blood clots and LDL cholesterol build-up. Chocolate, particularly dark chocolate, is believed to prevent artery and blood vessel damage. The key to consuming these two nontraditional health foods is moderation! It is the sugar in both that can hinder weight loss. Too much alcohol hinders glycogen storage and slows recovery following exercise, while consuming too much chocolate can easily can lead to an excess of calories.

As a personal fitness trainer and nutritional specialist, it will be your job to educate your clients about what foods to eat—just as Jessie’s personal fitness trainer did. Now that you know about the dietary fitness rules and how to fuel the body for various purposes, let’s talk further about the importance of protein. But before we do, use the following Practice Exercise to review what you’ve learned so far.

Step 5: Practice Exercise 6-1Select the best answer from the choices provided and write your answers on scratch paper.

1. To get the most out of her exercise program, a person should eat at least _____ times a day.a. threeb. four c. five d. six

2. A body that is in famine mode is likely to _____.a. never feel hungryb. store more of the food it receives as fatc. build muscle very efficientlyd. have a high metabolism

0203401LB02B-06-74


6-7

3. Which of the following is NOT a macronutrient? a. Fatb. Carbohydratesc. Sugard. Protein

4. When exercising to build muscle mass, it is important to consume enough _____.a. complete proteinb. incomplete proteinc. fatd. low-quality protein

5. The primary component of muscle tissue is_____.a. carbohydratesb. cartilagec. waterd. fat

6. One way to prevent feeling hungry throughout the day is to _____.a. eat a low-fiber dietb. drink less waterc. eat larger, less frequent mealsd. eat smaller, more frequent meals

7. The _____ is the only non-animal source of complete protein. a. flaxseedb. soybeanc. peanutd. lima bean

Step 6: Review Practice Exercise 6-1Check your answers with the Answer Key at the back of this book. Correct any mistakes you have made.

Step 7: Protein PowerConsuming adequate amounts of quality protein is essential to proper muscle function and repair. Let’s take a look at how the body uses protein, as well as the various types of protein available.

0203401LB02B-06-74


6-8

Types of ProteinProtein is contained in a variety of both plant- and animal-based foods. When choosing sources of protein, it is important to keep in mind the different qualities of protein. The availability of amino acids in a food and the way these amino acids are arranged determine the quality of protein. Animal sources of protein—known as quality or complete proteins since they contain all the essential amino acids—are arranged in a way that is most useful to the body. Soybeans and soybean products, such as tofu, also provide a source of complete protein. Complete protein sources that fit into a healthy diet include chicken or turkey, lean beef, fish, milk, cheese, yogurt and eggs.

Several plant-based foods also provide a source of protein; however, unlike animal-based protein sources, these foods don’t contain all the essential amino acids needed to perform bodily functions, including muscle maintenance and repair. When a person’s diet is lacking in one or more essential amino acids, protein formation is stopped, and the remaining amino acids are used as an energy source or converted to fat and stored.

Plant-based foods that contain at least some of the essential amino acids include beans, nuts, oatmeal, rice, pasta, peas, corn and peanut butter.

The Foundation of MuscleProteins are long chains of amino acids. Amino acids contain nitrogen, which is what links the amino acids together. Peptide bonds are the chemical bonds between the amino acids. Which amino acids compose a protein and the pattern in which these amino acids are arranged determine how the body will use the protein. All 20 amino acids, including the nine that are essential, are required to build and maintain muscle tissue. Because amino acids cannot be stored for long in the body, it is important to consume an adequate supply of all the essential amino acids each day.

Most of the body’s protein is in the form of skeletal muscle, bone and organs. Old cells in muscle tissue are constantly broken down and replaced using the body’s supply of amino acids. Gains in muscular strength and size are achieved when a muscle is worked to the point that it breaks down slightly and is then repaired to a greater degree than it had been originally. For the body to repair muscle tissue broken down during weight-bearing activity and other forms of exercise, it must receive adequate amounts of all the essential amino acids.

Winning CombinationsYou just learned that plant-based protein sources don’t contain all the essential amino acids. Two plant-based foods that, when combined, contain all the essential amino acids are called complementary proteins. Common examples of complementary proteins include beans with rice, peas with wheat, peanut butter with bread and corn tortillas with refried beans. Less common but equally effective combinations include cereal with legumes and whole grains with sunflower seeds. Grain products tend to be low in the essential amino acid lysine, while beans lack cysteine. Therefore, combining beans or legumes with grain products generally produces a complete protein source. Food combining is a common practice that vegans use. It once was thought that complementary proteins needed to be consumed at the same meal to be correctly utilized by the body, but recent evidence suggests that eating these foods within the same day is adequate.

0203401LB02B-06-74


6-9

How Much is Right for You?The body ensures that its energy requirements are fulfilled before using protein to build and repair tissue. So, when the body lacks the energy calories it needs from carbohydrates and fats, it uses protein instead. This means that when a person’s overall caloric intake is low, the protein requirements increase to ensure that enough is available for tissue maintenance.

Regardless of activity level or muscle mass, everyone has a daily dietary need for protein. For each pound of body weight, a person generally needs to consume .36 grams of protein each day. Therefore, a 160-pound person needs to consume about 58 grams of protein each day. To get this answer, simply work the equation .36 × 160 = 57.6.

Aerobic and weight-bearing exercises both increase a person’s daily protein requirement. This need for more protein is probably the result of the extra tissue repair that takes place following these activities, as well as the extra energy used during them. When a person is lifting weights to build muscle, his protein needs increase by about 50 percent. Thus, a 160-pound person who is weight lifting should consume about 87 grams of protein per day. Again, simply work the equation. Fifty percent of 58 is 29, so 58 + 29 = 87.

When estimating protein requirements, it is also is important to consider the quality of the proteins being eaten. It is recommended that at least 65 percent of protein intake be complete, containing all the essential amino acids necessary for tissue repair. A vegan diet generally requires more grams of protein than the estimation suggests since much of the protein a vegan consumes tends to be deficient in one or more amino acids. Also, physical exercise directly following protein intake tends to reduce the absorption and use of amino acids, further increasing protein requirements. Finally, keep in mind that pregnant women require more dietary protein than non-pregnant women.

Step 8: Carbohydrates: Fuel for the BodyWe’ve already talked quite a bit about carbohydrates in your previous lessons, but let’s do a quick review. Carbohydrates provide the fuel that the body needs to perform activity, just as gas provides the fuel a car needs to run. Surely you see that carbohydrates are especially important to anyone participating in an exercise program. It’s been more than 100 years since people first recognized the positive influence that a high-carbohydrate diet has on physical performance. Athletes today continue to use this insight through practices such as carbohydrate loading prior to exercise. We’ll talk more about this technique in a moment. But first, let’s take a look at the various types of carbohydrates and their influence on the exercising individual.

Types of CarbohydratesCarbohydrates are classified into three main groups. The first of these is the monosaccharide group which includes glucose, fructose and galactose. Monosaccharides are simple sugars composed of a single sugar molecule. You learned a bit about glucose already in this course. Glucose is the carbohydrate that circulates in the blood, providing the cells with energy. Glucose is not sweet; therefore, aside from its use in some sports drinks, it is generally not found by itself in the foods we eat. A second monosaccharide, fructose, is responsible for the sweet taste of foods, such as honey, fruit and carbonated soft drinks.

A third monosaccharide is galactose, which is found in lactose and some gums.

0203401LB02B-06-74


6-10

The second group of carbohydrates is the disaccharides, and these carbohydrates are composed of two simple sugar units. These sugars include lactose, sucrose and maltose. Lactose, the sugar found in milk, is formed when the two monosaccharides glucose and galactose combine. Remember, in Lesson 5 you learned that people who have difficulty digesting this disaccharide are lactose intolerant. Sucrose is a combination of the monosaccharides glucose and fructose. Sucrose is found in many types of fruit and can be obtained from sugar cane in the form of white, brown or powdered sugar. Maltose is the carbohydrate found in beer as a result of the fermentation process. It is composed of two glucose molecules linked together and often results when the body breaks down one of the more complex carbohydrates, which we’ll discuss next.

A third group of carbohydrates is the polysaccharides, which are often composed of up to one thousand individual glucose units. Therefore, these are known as complex carbohydrates. One of the polysaccharides of extreme importance to the exerciser is glycogen, which is essentially stored energy composed of glucose units. The majority of glycogen is found in the muscle tissue, while the remaining amount takes up residence in the liver. You know that glycogen is the fuel for muscles.

Just as humans store energy in the form of glycogen, plants store their energy in the form of starch, a second type of polysaccharides. Grains, such as rice or pasta, beans, vegetables and nuts, all serve as good sources of starch. Starch must be broken down into its glucose components before the body can use it as an energy source. A final type of polysaccharide is dietary fiber, which we discussed in the previous lesson. Dietary fiber is found in the plant cell wall and is resistant to human digestive enzymes. Nonetheless, these polysaccharides serve an important function in regulating digestion and preventing disease.

Metabolic Fuel: Aerobic versus AnaerobicYou learned about aerobic and anaerobic exercise in Lesson 4, but now let’s take what you learned and apply it to nutrition. Many sports require a combination of both aerobic and anaerobic activity. For example, running up and down the court during a basketball game serves as aerobic exercise, while jumping to rebound the ball is a form of anaerobic activity. Eating enough carbohydrates to provide adequate glycogen ensures the maximum performance in both aerobic and anaerobic activities.

Eating a meal high in carbohydrates prior to exercise offers several advantages over meals that are high in fat and protein. Carbohydrates replenish glycogen stores, take less energy to digest than protein or fat and can be absorbed and used as energy fairly quickly. Furthermore, carbohydrates don’t make a person feel weighted down, and they require less water during digestion. This lowers a person’s chance of dehydration. While what is consumed less than four hours prior to exercise can affect one’s workout, what a person eats on a regular basis also plays an important role in physical performance.

Whether a person participates in aerobic exercise, anaerobic activity or a combination of the two, it is important to replace glycogen stores after exercising so the body will recover properly. This is why Carrie wanted Jessie to eat more carbohydrates. Eating within 90 minutes after an activity helps the body repair itself most efficiently, and a meal that includes carbohydrates, as well as some fat and protein, is best. Protein consumed following a workout not only helps build and repair muscle tissue but also allows carbohydrates to get into muscle more efficiently, and this helps rebuild glycogen stores.

0203401LB02B-06-74


6-11

The Effect of Carbohydrate on Muscle GrowthA person who fails to take in an adequate amount of carbohydrates to sustain activity level inevitably will cut into the protein supply that his body normally uses to build and repair muscle tissue. When the body uses protein for energy needs, it depletes the only resource available to repair muscle tissue following exercise. Without enough protein, an exerciser will not make the gains in muscle strength and size expected. The body always fulfills its energy needs prior to its bodily maintenance needs, making a diet that provides adequate carbohydrates for energy important in building muscle tissue. The exerciser who keeps his glycogen stores up enables his body to build muscle efficiently.

You know that the body prefers to use carbohydrates as its primary source of energy. The average person is only capable of storing enough glycogen to fuel about 90 minutes of activity. Because of this, many endurance athletes utilize a technique called carbohydrate loading to increase the amount of glycogen that their bodies store. A common tactic in carbohydrate loading would be to eat a high carbohydrate diet for three days prior to the event while gradually reducing the amount of exercise one does each day. The day before the event, the athlete only rests. Carbohydrate loading can increase muscle glycogen stores by 20 to 40 percent, providing athletes with more energy to burn during their activity.

The Low-carbohydrate TrendThe trend in the nutrition industry in recent years has been toward low-carbohydrate dieting. With such a diet, a person eats very few calories, if any, from bread, pasta, potatoes, fruits and dairy, while eating more meat, eggs and other high-protein foods. Despite their current popularity, these diets are problematic in several ways, especially for those participating in a regular exercise program.

Without carbohydrates that can be used as an energy source, the body shifts into a state called ketosis. Ketosis occurs when the body burns fat and fat-like compounds called ketones as an energy source. Ketosis increases fluid loss, resulting in an initial weight loss of five or more pounds during the first few days of the diet. Dieters encouraged by this initial weight loss often continue dieting without realizing that their weight loss can be attributed to water loss.

When a person is not eating enough carbohydrates, the brain is also forced to find an alternate energy source. Unlike the body, the brain cannot fuel itself on fat and instead must break down muscle tissue into its amino acid components. The amino acids are then converted to glucose and used to fuel the brain. Muscle breakdown depletes a person’s muscle mass, resulting in a slower metabolism. The decreased muscle mass and slowed metabolism that result from low-carbohydrate dieting explain why people tend to gain weight quickly when they quit this diet.

Aside from the loss of muscle tissue that low-carbohydrate diets create, there are other concerns with these diets. Depriving the body of carbohydrates—its favorite energy source—tends to lead to chronic low energy levels and fatigue. Remember what Jessie said? This side effect can be especially troubling for athletes and other physically active individuals. Furthermore, many carbohydrate-rich foods provide key vitamins and minerals, such as Vitamin C, folic acid and calcium, as well as fiber. You already know that failing to consume these vitamins and minerals results in a deficiency. Also, many high-protein foods, such as meat and eggs, are high in saturated fat and cholesterol, increasing a person’s risk of developing heart disease.

0203401LB02B-06-74


6-12

The Interaction of Proteins and CarbohydratesWhether at rest or during exercise, the body relies on protein, fat and carbohydrates to function at its best. These three components must interact in various ways to provide the body with energy and to ensure proper maintenance and repair of tissue. When the body is at rest, it takes about 70 percent of its energy needs from fats and the remaining 30 percent from carbohydrates. During activity, the body shifts to carbohydrates as its main energy source. In fact, carbohydrates almost exclusively fuel exercise done at a high intensity.

You already know that when exercise continues for longer than 90 minutes or when glycogen stores have been depleted, the body uses protein as its energy source. Any time protein is used as an energy source, the amount left for muscle and tissue repair is reduced. Incomplete protein that cannot be used for muscle maintenance and repair is automatically converted to be used as energy. So, to ensure his body has the resources needed to build muscle, an exerciser must take in enough carbohydrates to fuel his activity, as well as an adequate amount of complete protein. As a personal fitness trainer, you must ensure that your clients understand this concept.

Step 9: Amino Acids Affect Muscle FunctionWe’ve already discussed amino acids in this course. However, in this section we will discuss the role that amino acids play in keeping the body healthy.

The Essential Amino AcidsThe nine essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. For some adults, histidine is considered nonessential since their bodies make enough naturally, while other adults, as well as most infants, lack this ability.

Nitrogen BalanceAll amino acids contain nitrogen. Remember that nitrogen is the substance responsible for the bonding together of individual amino acids into long chains—peptide bonds—that serve the body. The protein found in muscle tissue is constantly broken down and built up again. Any time muscle tissue is broken down it means that the amino acid chains are broken. When amino acid chains break apart, they release nitrogen, which is then excreted from the body.

Measuring the amount of nitrogen the body excretes and comparing it to the nitrogen intake is a common method used to determine whether an individual is building or losing overall muscle mass. A negative nitrogen balance, in which the body excretes more nitrogen than it takes in, points toward a loss of muscle mass. A positive nitrogen balance indicates muscle growth.

There are several things that lead to a negative nitrogen balance, especially in individuals who exercise vigorously. If one or more of any of the essential amino acids is lacking in the diet, the body reduces the rate at which it forms amino acid chains. The slowed production of new chains leads to a negative nitrogen balance. Vegans or those whose diets lack complete sources of protein are at an increased risk of a negative nitrogen balance.

0203401LB02B-06-74


6-13

Another possible cause of a negative nitrogen balance is a disproportionate intake of some amino acids compared to others. This is likely to occur when someone takes amino acid supplements that supply so much of one or more amino acids that the body’s ability to correctly synthesize amino acid chains is disrupted. Exercise, especially when it immediately follows the eating of protein, increases the rate at which the body breaks down amino acid chains. This is one reason why people’s protein needs increase when they participate in an exercise program.

Intensive exercise, even weight-bearing exercise, can actually lead to a net loss in lean muscle tissue if the body doesn’t have enough complete protein intake to offset muscle breakdown. Furthermore, by not providing the body with adequate glycogen stores, a person encourages the breakdown of amino acid chains and muscle tissue for energy needs. Therefore, if a client ever asks why he is not building muscle, you can explain that he must take in more complete proteins!

Step 10: The Role of Lipids in the BodyLipids are substances that contribute to the overall functions of the body and are considered an energy source. While it’s unclear how much of these substances one should consume, it is clear that eliminating lipids from a diet will affect the amount of energy a person has. One property that all lipids share is that they are only soluble or dissolvable in fat. If you’ve ever tried to mix oil with water, you know that oil, one type of lipid, will always separate itself from water. It simply won’t dissolve in it the way other substances do. The three main types of lipids are simple lipids, compound lipids and derived lipids.

The most common type of simple lipid found in both our food and bodies is triglycerides. Triglycerides are formed when three fatty acids attach themselves to one glycerol molecule. Fatty acids are composed of several hydrogen and carbon atoms. We already learned a bit about fatty acids in the previous lesson. Omega-3 and omega-6 are the two essential fatty acids, meaning the body needs to obtain them through diet. In Lesson 5 we learned what foods to eat to give the body these essential fatty acids. Consuming foods, like salmon, nuts and sunflower oil, gives the body simple lipids and, therefore, energy.

One type of compound lipid serves as a structural component of cell membranes, ensuring that nutrients move into and out of cells efficiently. Another type of compound lipid is a carbohydrate containing lipids that act mainly as structural components in the body. This compound lipid is found in the brain and nerve cells and contributes little as an energy source.

A final type of compound lipid is lipoprotein, which is a lipid that contains a protein component. You probably recognize the term lipoprotein from the discussion about cholesterol in a previous lesson. The main function of lipoproteins is to transport other lipids throughout the body so that all cells get the fat-soluble vitamins and essential fatty acids they need to remain healthy. You’ll remember that high-density lipoprotein or HDL is the good cholesterol that protects the heart by removing excess cholesterol from the blood and taking it to the liver where the body can excrete it.

Derived lipids have this name because they are derivatives of both simple and compound lipids. Examples of derived lipids found in the human body include steroids and alcohols. Derived and compound lipids combined make up just five percent of all lipids in the body.

We’ll discuss steroids further, as well as a few other topics, in a moment. But first, let’s review what you’ve learned with a Practice Exercise.

0203401LB02B-06-74


6-14


1. _____ are the chemical bonds between the amino acids. a. Acid bondsb. Peptide bondsc. Amino bondsd. Lipids

2. An example of a complementary protein is _____.a. beans with red meatb. corn tortillas with lettucec. peanut butter with breadd. wheat with milk

3. How many grams of protein does a 110-pound woman need to consume each day? a. 40b. 58c. 36d. 110

4. _____ are carbohydrates composed of two simple sugar units. a. Monosaccharidesb. Polysaccharidesc. Starchesd. Disaccharides

5. The body prefers to use _____ as its primary source of energy.a. amino acidsb. carbohydratesc. dietary fiberd. peptide bonds

6. The average person stores enough glycogen to fuel _____ minutes of exercise.a. 30 b. 60 c. 90d. 120

0203401LB02B-06-74


6-15

7. During ketosis, the body burns _____ as an energy source.a. fatb. carbohydrates from glycogen storesc. protein from muscle tissued. polysaccharides

8. A _____ nitrogen balance tends to indicate muscle growth.a. positiveb. negativec. neutrald. normal

9. _____ are composed of several hydrogen and carbon atoms. a. Compound lipidsb. Triglyceridesc. Lipoproteinsd. Fatty acids

10. Lipoprotein is a lipid that contains a _____ component.a. carbohydrateb. proteinc. lipitord. proprotein


Step 13: SupplementsFood is the best source for obtaining the vitamins and minerals necessary for optimal health. However, there are cases when the use of dietary supplements helps ensure that all nutritional requirements are met. As a personal fitness trainer and nutritional specialist, it will be necessary for you to identify the common supplements that those participating in an exercise program or focusing on a lifestyle of wellness might take.

The Importance of IronIron is a mineral that plays several important roles in the body. An adequate supply of iron in the blood ensures that oxygen is getting to all body cells. When cells have plenty of oxygen, they are best able to convert food into energy that the body can use. So, consuming enough iron is vital to an exerciser’s energy and overall performance. Iron-deficiency anemia is perhaps the most common deficiency in the United States. It affects as many as 58 percent of all females. Besides women, other groups at risk for iron-deficiency anemia include adolescents and athletes.

0203401LB02B-06-74


6-16

Factors that lead to an iron deficiency in athletes include heavy training, decreased iron absorption, breakdown of red blood cells during exercise, gastrointestinal bleeding, iron loss through sweating and inadequate dietary intake. Vegetarians are more likely to suffer from iron deficiency since the iron that plant sources supply is not as readily absorbed as the iron obtained from animal sources. When symptoms of iron deficiency, such as fatigue, are present, a simple blood test can confirm the diagnosis. Treatment includes increased dietary iron intake, as well as supplementation.

Increasing Calcium IntakeCalcium is a mineral that composes much of the bone tissue found in the body. From birth we must obtain all our bodies’ calcium needs from dietary sources. Calcium supplements may be necessary particularly for those who avoid dairy products or have a low caloric intake. Exercise increases the rate at which the body breaks down bone. Physically active people must be sure to meet their calcium needs if they want to avoid bone loss.

Loss of bone tissue over time can lead to the disease osteoporosis, about which you’ve already learned. Many things put one at greater risk for developing this disease, including being a woman of thin build, Caucasian or Asian ethnicity, low caloric intake, smoking and inadequate calcium intake. Osteoporosis is a complex disease with many contributing factors ranging from hormonal fluctuations to genetic background. However, taking a daily calcium supplement is often helpful in preventing this disease and is recommended for those at risk.

Some People have Special NeedsToday, we know that some groups of people require more of certain vitamins and minerals than others to function at their best. For example, women of childbearing age—especially those who are pregnant—require more folic acid. Our client Jessie falls into this category. Those taking oral contraceptives have an increased need for several vitamins, such as thiamin and riboflavin. Smokers should consume more Vitamin C, while heavy drinkers require more of the B vitamins.

Older people may need higher amounts of all vitamins and minerals as a result of their bodies’ decreased absorption abilities. Those who take certain medications or are recovering from surgery, illness or injury also can benefit from supplements. Along with a healthy, balanced diet, taking a daily multivitamin helps ensure that your client is providing her body with all the vitamins and minerals it needs to function properly.

Athletes and SupplementsWhen advising the use of supplements as a personal fitness trainer and nutritional specialist, it is important to consider each client’s case individually. In doing so, you will be able to make a recommendation that will prove most beneficial to that person. Some supplements can have a positive impact on athletic performance, especially if the diet is deficient in certain vitamins and minerals. Diets lacking in key vitamins and minerals hinder athletic performance. Therefore, supplementation in these cases provides the body with what it needs to perform at its best. People who restrict food intake or avoid certain food groups are most likely to need supplementation to meet their daily vitamin and mineral requirements.

0203401LB02B-06-74


6-17

Those who participate in vigorous exercise or weight training may also benefit from additional supplementation because of the physiological changes to which this type of activity leads. Some people assume that as long as one has an adequate caloric intake to support her level of activity, she is also supplying her body with enough vitamins and minerals. However, it is now believed that—as a result of the increased demand for tissue repair found in those training heavily—the need for some vitamins and minerals exceeds the amount ordinarily obtained from the diet. In these cases, supplementation can provide an athlete with the necessary vitamins and minerals to ensure proper tissue repair and optimal performance.

A final important consideration when it comes to supplementation is the psychological influence of the supplement. Some people feel that taking a supplement helps them to perform better. The placebo effect occurs when a person’s belief that something has an effect results in a real physical change. For example, when someone gets confidence from taking a supplement, even if there is no proof of that supplement’s impact, discontinuing use of the supplement may have a powerful effect on the person’s state of mind. It may, in fact, be detrimental to his or her physical performance. In cases like these, the continuation of the supplement is fine as long as it poses no serious health threat to the taker.

Supplements also can help the body recover from illness or injury, which we’ll discuss next.

Step 14: Fueling to Recover from Illness or InjurySustaining an injury can be a frustrating experience for both the new and seasoned exerciser, as it often delays a person’s ability to reach her fitness goals. However, even when sidelined with an illness or injury, a person can use a healthy diet to improve her overall health and speed recovery time. Many of the following eating guidelines can even help prevent injury from occurring in the first place.

When people stop exercising because of an injury, they often cut back their caloric intake to prevent weight gain. This, however, can lengthen recovery time since the body needs extra calories to repair an injury or fight off an illness. It also is important to keep protein consumption up to maintain muscle and other soft tissue. Likewise, chronic dieters put themselves at an increased risk of injury since a caloric deficit causes the body to use protein stores as an energy source. This often leads to impaired muscle repair and muscle tears.

Eating Well To Get and Stay HealthyWhen some people begin a new exercise program, they see it as an excuse to eat whatever they want. What they may not realize is how important a part their diet plays not only in achieving their fitness goals but also in their exercise performance and overall health. Remember, our client Jessie didn’t realize the impact her diet had on her ability to get in shape until she spoke with Carrie. Failing to give the body what it needs to recover from a workout can result in sore muscles and overall fatigue. This, in turn, may delay the next workout or hinder the quality of that workout—both of which act as setbacks to achieving fitness goals. After a workout the body needs both protein and carbohydrates to repair itself and replace valuable glycogen stores.

Eating the right foods at the right times also plays an important role in determining a person’s mood and energy level. Low blood sugar results from failing to eat enough of the right foods or waiting too long between meals. Many people function better and have more energy when they eat more frequent, miniature meals throughout the day. This is because it keeps their blood sugar stable. Skipping meals is not advised. And remember, in this lesson you learned that eating three balanced meals along with two separate snacks each day is a good way to improve dietary habits.

0203401LB02B-06-74


6-18

Optimal glycogen stores ensure good muscle endurance throughout a workout. When the body runs low on these stores it may resort to breaking down muscle protein for energy, leaving a person at greater risk for injury. Failing to consume adequate amounts of fruits and vegetables deprives the body of the phytochemicals necessary to protect joints, and this further increases injury risk. Skimping on dairy products and red meat, a common practice among athletes, can deprive the body of the calcium, zinc and iron it needs to maintain healthy bones and muscles.

A healthy diet should remain a top priority, even when a person is sidelined with an injury or illness. Many athletes don’t meet their daily iron and zinc needs. Consuming a zinc- and iron-fortified cereal or taking a supplement that provides these minerals may help prevent and repair injuries. In addition, the calcium contained in dairy products, some leafy green vegetables and numerous other calcium-fortified products is essential to the repair of stress fractures and other bone injuries.

Vitamins A and C each play unique roles in tissue repair, making them important contributors to injury recovery. Yellow, orange and leafy green vegetables all contain beta-carotene, which is converted to Vitamin A in the body. The body then uses Vitamin A to make new tissue, aiding in injury repair. Vitamin C is needed to make collagen, a protein contained in bone and connective tissue. Think of collagen as the substance that glues an injured area back together. Consuming plenty of fruit, such as cantaloupe, berries and oranges, as well as vegetables like tomatoes and peppers, ensures the body is getting an adequate source of Vitamin C.

Two dietary supplements, glucosamine and chondroitin sulfate, may also be used to reduce inflammation, promote cartilage growth and prevent osteoporosis. Injury to a joint increases the likelihood of developing osteoarthritis, and taking these supplements may help reduce this risk while aiding in injury repair. Do keep in mind that glucosamine and chondroitin sulfate don’t last long in the body. Therefore, supplementation three times a day ensures availability.

Along with a nutritious diet, giving the body adequate rest is essential to its proper healing. While most people do what they can to ensure their bodies recover from illness or injury, some choose to damage their bodies by using steroids. Let’s discuss steroids in detail.

Step 15: SteroidsAnabolic steroids are substances related to the hormone testosterone. Testosterone is responsible for masculine characteristics, such as a deep voice, facial hair and increased muscle mass. When injected or taken orally, anabolic steroids produce or increase masculine characteristics. Some people may take anabolic steroids to increase their muscle mass despite the many risks and side effects associated with these substances.

How Do Steroids Work?All anabolic steroids work in a similar way—they create a positive nitrogen balance in the body, thus aiding in muscle building. A high enough dose of anabolic steroids can produce muscle mass gains in nearly anyone, including people who do not lift weights. The amount of steroids needed to foster muscle gain depends on an individual’s genetic tendencies. A few people gain muscle mass on a moderate amount of steroids, but the vast majority of the population requires high doses. The lean muscle mass that both men and women receive from the use of anabolic steroids can last for several months—even after steroid use is stopped and traces of the substance can no longer be detected in the blood. This is why drug testing during the time leading up to competitive events is common.

0203401LB02B-06-74


6-19

Without a positive drug test it is difficult, if not nearly impossible, to determine whether an individual is using steroids, but possible warning signs of steroid use include abnormally large increases in muscle size or strength in a short time period, the development of acne and changes in behavior, such as increased aggressiveness. A cholesterol screening may reveal abnormally low HDL levels, and this is also a common result of steroid use. But keep in mind that many of these symptoms can be attributed to other causes, and their presence doesn’t necessarily point to steroid use.

Steroids and PerformanceThere is a clear relationship between taking anabolic steroids and muscle mass gains. However, whether these gains lead to increased strength or improved athletic performance is less clear. No study to date has demonstrated a clear link between steroid use and improved athletic performance. Studies fail to show that steroids are able to do many of the things for which people take them, including better muscle endurance, improved sprinting abilities and shortened recovery times following workouts.

There are side effects that steroids cause that can adversely influence performance, such as unwanted increases in body weight, as well as declines in performance when steroid use is stopped. Furthermore, athletes who participate in team sports may find that the emotional outbursts that accompany steroid use hinder teamwork.

Dangers of Steroid UseWhile the relationship between steroid use and performance enhancement is questionable at best, the negative side effects that users experience are well established. A woman who uses steroids develops physical male traits, such as a deeper voice, loss of breast tissue and menstrual cycles, male-pattern baldness and increased facial hair. Some of these changes that take place with steroid use may not be reversible even after the substances are stopped.

A recent survey of male high school seniors revealed that seven percent admit to using steroids. Many adolescent males report using steroids because of the impact these substances have on their appearance, rather than for athletic purposes. About one-third of male adolescents using steroids don’t even participate in sports. While the initial result of adolescent males using steroids is accelerated physical maturation, the long-term consequences can include stunted growth, as steroids have been known to terminate bone growth prematurely.

Another negative side effect of steroid use is the accompanying changes in personality and behavior. Steroids may make individuals highly aggressive. Some people experience a loss of judgment and behave recklessly as a result of the hormone imbalances that steroid use creates. Even psychosis or a complete break from reality can occur in those taking high doses of steroids. Other health risks include liver tumors, problems with cholesterol levels and temporary infertility.

Hard work and proper diet are the safest and most effective means to accomplishing fitness and athletic goals. Personal fitness trainers and nutritional specialists should not advise or allow clients to use anabolic steroids. The use of these substances has no clear health or performance benefits, but they do put people at risk for developing serious and permanent side effects. Educating clients on the risks associated with taking steroids can be an important factor in preventing or ending their use.

0203401LB02B-06-74


6-20

Step 16: State of Mind The brain and body are connected in several ways. You know from a previous lesson about the psychology of wellness that a person’s mental state is very much connected to her physical and nutritional abilities. Therefore, when it comes to performance, the state of mind of an athlete often proves just as important as her physical abilities. As a personal fitness trainer and nutritional specialist, it will be important that you take into account the mind’s power over the body as you guide your clients toward their fitness goals. When considering physical performance, the brain and body interact in three ways:

● Voluntarily

● Involuntarily

● Hormonally

Whenever a person chooses to move, her body messages are sent from the brain and spinal cord to the bones and muscles, telling them what to do. Thought processes guide voluntary muscles. So, when a person wants her arms or legs to move, her brain can control this action.

Besides voluntary actions, the brain also sends out signals to individual blood vessels and organs, telling them to ensure the muscles have what they need to perform. The brain does this involuntarily, meaning it’s not something a person needs to think about doing or has any control over.

Finally, the brain causes the body to excrete certain hormones that play an important role in physical performance. For instance, the hormone testosterone plays a role in muscle maintenance during exercise.

Mind Over MatterSports psychology is a growing field that studies the relationship between an athlete’s psychological state and her physical performance. Many of the ideas that sports psychologists use also apply to the work of personal fitness trainers and nutritional specialists. Clients who are happy, feel positive toward their fitness plan and are open with their trainer are much more likely to achieve their fitness goals. Simply going through the motions of a wellness program is not nearly as effective as engaging both the mind and body in a healthy lifestyle. Personal fitness trainers can teach their clients to view the mind as another body part that, when exercised daily, contributes greatly to their overall fitness success.

People who are engaged in successful athletic performances share many of the same psychological characteristics as those who get the most success from their exercise programs. They are highly focused on the activity they are doing and feel a sense of effortlessness in their actions. Time may seem to slow as they concentrate on what they are doing from one moment to the next. Worrying about failure or engaging in negative self-talk only sets a person back from achieving his goals. People feel a certain amount of control over their bodies and a confidence in their abilities—both of which help them turn their visualizations into reality. By encouraging the engagement of both mind and body in an exercise program, personal fitness trainers and nutritional specialists help raise their clients’ level of success.

You are almost finished with this lesson! But before you take your Quiz, use the following Practice Exercise to review what you’ve learned.

0203401LB02B-06-74


6-21


1. _____ is perhaps the most common deficiency in the United States.a. Calcium-deficiency anemiab. The placebo effectc. Osteoporosisd. Iron-deficiency anemia

2. Which of the following groups is most at risk for developing osteoporosis? a. Black malesb. Asian femalesc. Adolescent boysd. Obese children

3. Smokers require more of which vitamin than nonsmokers? a. Vitamin Ab. Vitamin B5c. Vitamin Cd. Vitamin E

4. _____ results from failing to eat enough of the right foods or waiting too long between meals. a. Low blood sugarb. High blood sugarc. Osteoporosisd. Iron-deficiency anemia

5. To which hormone are anabolic steroids most closely related? a. Estrogenb. Testosteronec. Progesteroned. Lipoprotein

6. Which of the following is a consequence of anabolic steroid use in adolescents? a. Decreased facial hairb. Memory lossc. Bone lossd. Stunted growth

0203401LB02B-06-74


6-22


Step 19: Lesson SummaryTwo months into her new fitness and nutrition plan, Jessie is making great strides with the help of her personal fitness trainer, Carrie. She has reduced her overall body fat, increased her muscular and cardiovascular endurance and toned her body. Jessie found that incorporating healthy sources of carbohydrates into her diet improves her energy and gives her the fuel she needs to get through her workouts. To her surprise and delight the resistance training she engages in three times weekly has not bulked her up but has instead resulted in improved balance and coordination, as well as a sleek appearance she has not enjoyed since her early twenties. Most of all, Jessie enjoys the pride and feelings of accomplishment that completing each workout bring, and she looks forward to continuing her healthy lifestyle in the future.

Giving the body the fuel it needs is a vital aspect of any fitness program. In this lesson, you learned that what type and how much food you put into your body plays an important role in the physical performance you get out of your body. You saw how choosing the right supplements and ingesting certain nutrients contribute to staying healthy, preventing injury and repairing the body following exercise or illness. You also learned about the dangers associated with steroid use, as well as how an individual’s state of mind can affect physical performance.

Wow! You’re nearly finished with this lesson. You’re that much closer to achieving your goal of becoming a personal fitness trainer and nutritional specialist. Before you take the final Quiz, go back and read any sections you found confusing. And don’t forget to call your instructor should you have any questions or concerns. We are here to help you succeed in your new career! In the lessons to come you’ll begin to learn about anatomy, the muscles and the energy equation. Knowledge of these subjects will ensure your expertise in the world of fitness and nutrition!

Step 20: Quiz 6Once you have mastered the course content, locate this Quiz in your Assignment Pack. Read and follow the Quiz instructions carefully.

Lesson 7The Energy Equation


● Explain changes in the cardiovascular and respiratory systems during exercise.

● Identify the guidelines for cardiovascular activity.

● Describe how intensity, duration and frequency influence the effectiveness of aerobic exercise.

● Determine the importance of warming up and cooling down.

● Discuss the physiology of exercise and how the body uses glycogen and creatine phosphate to produce energy.

Step 2: Lesson PreviewIf you’ve ever watched a sporting event in person or on TV, you may have found yourself wondering, “How does the human body do that?” How is it possible to complete a triathlon, bicycle through France or run 26 miles? How do football players catch a pass and then outrun 11 other athletes for 20 yards or more? How do tennis players chase a fist-sized ball back and forth across the court?

A lot of the sporting events you see on TV showcase phenomenal athletes performing in important competitions. These athletes are more highly skilled than most of us. But the people running in a local 5K, cycling a few miles each day or hiking trails in your area every weekend are just people. They are more fit than the average person, but they probably aren’t professional athletes. Still, how do they achieve the results they do?

One part of the answer is that physically fit people have trained their bodies well. They have learned to take advantage of the body’s energy production systems and have taken the time to make those systems more efficient. In the process, they’ve improved their overall health. The starting point is learning how the body operates at rest; we talked about that in Lesson 4. Now, we’ll look at what happens to the body’s systems when we exercise.

As a personal fitness trainer and nutritional specialist, you should become familiar with the changes that the respiratory and cardiovascular systems undergo when a person exercises. You also must educate clients on guidelines for cardiovascular activity and show them how intensity, duration and frequency influence the effectiveness of aerobic exercise. And don’t forget to ensure your clients warm up and cool down when they exercise! If you’re unsure about how to do all of this, fear not! Read on, and you’ll learn all you need to know.

0203401LB02B-07-74


7-2

Step 3: It All Begins with OxygenYou learned about the respiratory system in detail in Lesson 4. We talked about all the parts of the respiratory system from the nose down to the tiny alveoli deep inside the lungs. You learned that the respiratory system gets oxygen into and removes carbon dioxide from blood, which the cardiovascular system sends through the body. You know that oxygen is one of the basic needs of every cell in the body; the other need is glucose. As you read this lesson, you might want to refer to the illustrations and terminology in Lesson 4. Now, we’ll do a little review of what you’ve learned in this course so far, as well as begin an in-depth look at the importance of oxygen.

Gas ExchangeWhen we breathe the air around us, the respiratory and pulmonary circulation systems exchange oxygen in the air for carbon dioxide in the blood. The exchange of carbon dioxide for oxygen and vice versa is called gas exchange, which you learned in Lesson 4. Gas exchange occurs at the level of the alveoli—those buds that cluster around the last bit of the bronchial tree, across the respiratory membrane.

Figure 7-1: The lungs and chest cavity

You should remember learning about external and internal respiration in Lesson 4. Well, external respiration is the same as gas exchange. Both types of respiration follow the law of diffusion. Each molecule of gas, whether carbon dioxide or oxygen, moves toward a place where that type of gas is less concentrated. Similarly, room deodorizers depend on diffusion; the scent in the container eventually spreads throughout the room. However, respiration occurs very quickly—nearly instantly.

Remember, the alveoli have a high level of oxygen, or are oxygenated, because the air feeds them every time we inhale. Meanwhile, the blood that’s coming into contact with the alveoli is deoxygenated, or has a low level of oxygen because it’s just left all of its oxygen with the cells. However, the blood has high levels of carbon dioxide, while the alveoli have low levels of carbon dioxide. So, the carbon dioxide moves quickly and easily into the alveoli, while the oxygen moves quickly and easily into the capillaries.

0203401LB02B-07-74

The Energy Equation

7-3

Respiratory PhysiologyNow that you understand gas exchange, let’s quickly review the processes in the respiratory system. The parts of respiration include:

● Pulmonary ventilation

● Gas exchange

● Gas transport

● External respiration

● Internal respiration

● Cellular respiration

Respiration and VentilationYou learned about external, internal and cellular respiration in Lesson 4. If you need to review these terms, refer to that lesson. When you use the term respiration, you might actually mean ventilation or breathing. These are common ways to use the term respiration, even though breathing is a huge simplification of everything that happens throughout the respiratory system. For the purposes of this lesson, we’ll use ventilation to mean breathing and respiration to refer to different places in which oxygen and carbon dioxide exchange places.

You also learned about pulmonary ventilation in Lesson 4, but now let’s discuss it in a bit more detail. It is what you and I know as breathing. During pulmonary ventilation inspiration pulls air into the lungs, while expiration moves air out of the lungs. Ventilation keeps the air in the alveoli fresh.

Figure 7-2: Pulmonary Ventilation

A spirometer is a device used to evaluate respiratory function. It measures many different aspects of ventilation:

● Tidal volume or TV—The amount of air that moves in or out of the lungs during quiet breathing.

● Inspiratory reserve volume or IRV—The amount of air inhaled in forced inspiration; the largest breath you can take.

0203401LB02B-07-74


7-4

● Expiratory reserve volume or ERV—The amount of air exhaled in forced expiration; how much air you can blow out.

● Residual volume or RV—The amount of air that isn’t moved, even with the greatest forced inspiration and expiration. It’s normal to move only part of the air in and out of the lungs with each breath. Think of it like this. You have a bucket of water, and you want to exchange all the water in the bucket for new water, one cup at a time. You take out a cup of water; you add a cup of water. Eventually, the water in the bucket is all new water. But at any given time, the bucket isn’t empty.

● Vital capacity or VC—The total amount of air that can be exchanged in the lungs under the best conditions. It includes TV, IRV and ERV.

● Dead space volume or DSV—The amount of air that remains in the respiratory passageways and never reaches the alveoli.

● Total lung capacity or TLC—The total air volume of the airways throughout the lungs; the sum of the vital capacity and the residual volume.

Remember, gas exchange is the process through which oxygen and carbon dioxide trade places in the blood. Gas transport is the process of moving oxygen in red blood cells from the lungs to the cells in the rest of the body and moving carbon dioxide back again. The systemic and pulmonary circulation systems—parts of the cardiovascular system—handle this process.

Figure 7-3: Internal and External Respiration

0203401LB02B-07-74

The Energy Equation

7-5

Putting It All Together: Normal Oxygen DeliveryYou know that you inspire air when your diaphragm muscle contracts, and when the diaphragm relaxes, you expire to push air out of the lungs. As air moves through the nose, it passes through the nasal cavity, where it is warmed, moistened and filtered. It then passes through the pharynx and larynx and into the trachea or windpipe. The trachea is divided into two bronchi, which divide into smaller and smaller branches. The smallest branches are bronchioles, which end in clusters of alveoli. One set of lungs has more than 300 million alveoli! The porous walls of alveoli come into contact with blood in the capillaries, where gas exchange takes place to oxygenate the blood. Do you remember learning about all of this in Lesson 4?

The oxygenated blood is circulated to the heart and from there to each cell in your body. As the blood moves through the capillaries and contacts each cell, gas exchange occurs again, and the cells are oxygenated while the blood is deoxygenated. The systemic circulatory system then sends the blood to the heart, which routes it back into the lungs for more oxygen.

Imbalance in Oxygen ExchangeThe previous section describes normal oxygen delivery. For most of us, functioning somewhat normally while just sitting about is pretty undemanding. Even fairly easy movements, like pouring a cup of coffee or walking to the conference room to see if anyone brought donuts, aren’t likely to tax our respiratory systems.

However, running up the stairs, throwing newspapers or dashing for the bus puts a new strain on the delivery of oxygen. Altitude and smoking also have a huge impact on the way oxygen moves through the body. As a personal fitness trainer and nutritional specialist, you should have an understanding of how the respiratory system responds to exercise.

Oxygen and ExerciseIf you go out for a brisk walk, at what point do you think, “I should start breathing more often now?” For most people, the answer is, “Never.” That’s because your brain does an excellent job of taking care of your rate of ventilation. It automatically adjusts the rate to meet your body’s demands with the goal of minimizing the overall difference in the amount of oxygen getting to your body’s cells. After all, they need a steady supply of oxygen, and they need to get rid of carbon dioxide.

So what does your brain do? Well, it not only triggers inspiration and expiration, it also controls the rhythm of respiration. Your brain controls how long it takes for your lungs to fill, which increases the rate at which the ventilation process occurs. Your brain also acts as a ventilation coach, urging the ventilation process to occur more frequently and giving your abdominals a little extra encouragement to forcefully exhale.

When you start that brisk walk, your muscles need more oxygen. The amount of oxygen that your body’s tissues consume is called oxygen uptake—in Lesson 4, we called it VO2. Aerobic exercise that requires movements of larger masses of muscles or greater work levels requires more oxygen uptake. Maximal oxygen uptake—VO2 max—is the greatest amount of oxygen that your body can use at the cellular level.

0203401LB02B-07-74


7-6

The amount of oxygen your muscles need is determined by:

● how much work you’re asking your muscles to do—are you walking uphill or downhill?

● how efficiently your muscles use oxygen to create energy—how well have you trained them?

● the mass of the muscles themselves—the big ones, like the legs, use more than the small ones, like those in the fingers.

In general, maximal oxygen uptake is one of the most widely accepted measurements for cardiopulmonary fitness. How well your body uses oxygen—that is, what your own maximal oxygen uptake is—depends on two things. The first is how well the heart and circulatory systems transport oxygen. The second is how well your body’s cells use the oxygen. The higher your maximal oxygen uptake, the more fit you are.

Oxygen uptake is measured in two ways. The first measurement is in milliliters of oxygen per kilogram of body weight per minute or ml/kg/min. A basic resting oxygen uptake is 3.5 ml/kg/min. This value also defines the second measurement. One metabolic equivalent or MET is 3.5 ml/kg/min. It is the amount of energy it takes to rest. Some fitness organizations develop exercise intensity charts based on the number of METs an exercise uses. Using METs in this way lets you easily see how strenuous an exercise is as compared to being at rest.

Normal maximal oxygen uptake in healthy people ranges from 25 to 80 ml/kg/min. So what would that range be in METs? Well, you know that one MET is 3.5 ml/kg/min. Therefore, you divide 25 by 3.5 and 80 by 3.5 to get a range of 7.1 to 22.9 METs. This value varies widely because so many physical factors influence the body’s ability to work, such as age and fitness level, for example.

For your clients to improve their performance of any particular aerobic exercise, they have to improve their maximal oxygen uptake, or VO2 max. Improving VO2 max is one component that helps people run faster. Fortunately, doing aerobic exercise regularly also, over time, increases VO2 max. However, most of the increase comes from improving the cardiovascular system, not the respiratory system. We’ll talk about what happens when you exercise your cardiovascular system later in this lesson.

So, what happens to your respiratory system when you engage in regular aerobic exercise? You should remember reading about some of these changes to the system in Lesson 4. During light aerobic exercise, the volume and frequency of ventilation both increase. That is, you breathe more often and more deeply. This also happens when you exercise at maximum capacity. But when you exercise at a submaximal (less than maximum) capacity, your frequency of breathing decreases while the depth of your breathing increases. This change in breathing during submaximal activity is from specific changes in the muscles that you’re used to working. For example, if cycling is your primary sport, you’ll notice these changes while cycling but not while swimming, because cycling and swimming use different muscle groups.

Another important change to your respiratory system is that your ventilation becomes more efficient. That is, your body uses more of the oxygen you breathe. This improvement occurs from changes deep in the cells of the muscles in your body. Aerobic exercise increases both the number of mitochondria in your muscle cells and their size. It’s these mitochondria that are responsible for producing energy; more and bigger mitochondria can pull more oxygen out of the blood.

0203401LB02B-07-74

The Energy Equation

7-7

If you think of your muscle cells as little energy factories, the capillaries are huge conveyor belts that pass through the factory. The conveyor belts contain blood that is rich in oxygen, which is one of the primary raw materials for producing energy. The mitochondria are like factory workers. They pull oxygen molecules off the conveyor belt to make energy. More factory workers, and bigger factory workers, can pull more molecules of oxygen off that conveyor belt.

What Else Stresses the Respiratory System?A few minutes ago we mentioned that exercise isn’t the only thing that stresses your respiratory system. Anything that gives your body less oxygen to use will influence how well your body functions. Fortunately, the human body is highly adaptable.

Altitude greatly affects your respiratory system, because at higher elevations the air contains less oxygen. If you’ve ever taken a trip to the mountains and felt tired, that’s why! Your system is getting a lot less oxygen than the amount it’s used to getting. At about 3,900 feet, the body starts to make changes to compensate for this lack of oxygen. At first, your rate of ventilation increases—this happens at rest as well as during exercise. Although your muscle strength is relatively unaffected, your heart also adapts to the reduced levels of oxygen, increasing its output anywhere from 30 percent to 50 percent.

Overall, the result is that your body will perform aerobic activity worse than usual when you first exercise at a higher altitude. Over three to six weeks, your body may adjust enough that it can perform nearly as well as it did at sea level, but it may always perform slightly worse at that higher altitude. However, after adjusting to the altitude and returning to sea level, your performance may be better for a month or so before your body readjusts to the oxygen-rich air. This is why some athletes—especially marathon runners—prefer to train in places with high altitudes.

Another huge influence on your respiratory system is smoking. Some lung problems and diseases that smoking causes don’t appear until later in life. However, smoking tobacco impairs the ability of your lungs to function in several ways.

● Nicotine constricts the bronchial tree, closing off some of the airway.

● Smoke irritates the bronchial tree, causing swelling and further restricting the path of air.

● Nicotine paralyzes the cilia, which are fine hairs on the surface of the respiratory tract that are responsible for removing foreign substances and excess fluids. When the cilia are paralyzed, garbage accumulates in the respiratory system.

● Carbon monoxide, which is a component of cigarette smoke, binds with red blood cells to crowd out the oxygen that the respiratory system wants to transport.

The result of all of these changes is that your respiratory system is more strained. Even for light smokers, maximal exercise capacity is reduced, the heart has to work harder during light exercise and heart rate and blood pressure increase.

Now that you know how the respiratory system reacts to exercise, you’ll be able to explain this to your clients! Next, we’ll review the cardiovascular system and examine the role it plays in exercise.

0203401LB02B-07-74


7-8

Step 4: Blood Moves the OxygenIn Lesson 4, we learned about the cardiovascular system. To review, it’s the body’s delivery system for nutrients like oxygen, glucose, amino acids and hormones. It even carries off the waste products from metabolism in the cells. Although we may think of the heart as the primary part of the cardiovascular system, the entire system includes the heart, blood vessels, lymph vessels and the blood or lymph they contain.

The heart dispatches blood in regular shipments to the rest of the body. The heart itself is divided into four chambers: atria on the top and ventricles on the bottom, with one atrium and one ventricle on the right side and one of each on the left side. Arteries carry blood away from the heart, while veins return blood to the heart.

In the heart, the blood flows in only one direction. Cardiac valves are designed to prevent any backwash of blood and keep the blood moving in the proper direction.

Figure 7-4: External Cardiac Anatomy and Coronary Arteries

Blood in MotionNow, let’s review how blood moves throughout the cardiovascular system. Remember, cardio refers to the heart, while vascular refers to veins, arteries and capillaries.

The right side of the heart receives blood from the body through systemic veins—the superior and inferior venae cavae. This blood has delivered its oxygen load to the cells. First, the blood flows into the right upper chamber, the right atrium. It passes into the right ventricle, where it is pumped through pulmonary arteries to each lung. At the lungs, it gives off carbon dioxide and receives a fresh supply of oxygen, then returns to the left side of the heart through pulmonary veins. The blood fills the left atrium and passes into the left ventricle, where it is pumped through the aorta to take its supply of oxygenated blood to the rest of the body.

Arteries branch off into smaller and smaller vessels until they feed the capillaries. Capillaries are the smallest blood vessels in the body. Oxygen exchange occurs in the capillaries. From the capillaries, the blood moves into small veins and systems of small veins join to become larger veins. Eventually, the veins return the blood to the heart through the superior and inferior vena cavae.

0203401LB02B-07-74

The Energy Equation

7-9

Cardiac PhysiologyMost of us take our heartbeats for granted—except when we fall in love or go to scary movies. Then, we may feel them fluttering or pumping wildly. Your heartbeat is actually a complex interaction between muscles and nerves. The heart is an involuntary muscle that contracts at a regular rhythm. Even when it’s removed from the body, the heart can beat on its own for at least 30 minutes!

The cardiac muscle cells contract on their own, without stimulation from the nervous system. Their contractions are continuous and regular. However, each part of the heart has its own rhythm of contraction. The atria contract at about 60 beats per minute—roughly, once a second. However, the ventricles contract less often, at about 40 beats per minute.

A system inside the heart muscle itself controls cardiac rhythm. The system coordinates the different rates in the parts of the heart so that the blood moves smoothly from the atria into the ventricles and from the ventricles into the circulatory system. It coordinates the overall heart rate—your pulse—which averages 60 to 90 beats per minute.

An electrocardiogram, also known as an EKG or ECG, measures the electrical conductivity—the activity and pattern—of the heart. From the EKG, physicians can predict heart problems, such as decreased blood flow, or ischemia, and cell death, or cardiac infarction.

Moving Faster: The Exercising HeartSo far, everything we’ve reviewed here pertains to how the heart and the rest of the cardiovascular system function during normal circumstances. Now, let’s look at how the system changes during exercise.

Remember, the cardiovascular system’s job is to deliver oxygen to muscles. That doesn’t change, even when the body is working through the stress of exercise! The changes to the cardiovascular system that occur during exercise include:

● Changes in cardiac output

● Changes in stroke volume

● Changes in heart rate

● Changes in the capillaries

First, let’s review some of these terms that we talked about in Lesson 4. Cardiac output is the amount of blood that the heart pumps. It is measured by multiplying stroke volume, which is the amount of blood forced out with each beat, by the heart rate or pulse. You can see where the changes listed above are interrelated!

Now, let’s talk about how the cardiovascular system changes during exercise. You probably remember reading about some of these changes in Lesson 4. When you go from a relaxed state to aerobic exercise, cardiac output increases. At first, it increases rapidly. Then, the rate of increase slows until it reaches a plateau. When you’re performing maximal exercise, your cardiac output may be four times as much as it is when you’re at rest! Similarly, stroke volume increases when you start exercising and continues until you’re at 50 percent to 60 percent of maximal oxygen consumption, where it plateaus. Also, a reflex causes the heart rate to go up when you start exercising. Your heart rate increase depends a great deal on your fitness, age and the workload you’re asking of your heart.

0203401LB02B-07-74


7-10

As you train your cardiovascular system with aerobic exercise over time—say, six to 12 months—your stroke volume increases. In other words, each heart contraction moves more blood through the system. Therefore, when you’re at rest, your heart has to beat less frequently, so your heart rate will decrease. And because your stroke volume increases, your cardiac output increases. Also, when an aerobically fit person begins exercising, her heart rate increases less quickly than the heart rate of a less-fit person. So, the more aerobically fit you are, the less strenuously your heart has to work.

One other benefit is that a physically fit person has more capillaries feeding the organs and tissues of the heart. More capillaries means that more oxygen, nutrients and hormones are delivered to the cells, and more heat and carbon dioxide are removed from the cells.

In a few moments we’re going to further explore the cardiovascular response to exercise. But first, use the following Practice Exercise to review what you’ve already learned.


1. The two gases that the respiratory system uses are _____. a. oxygen and carbon monoxideb. oxygen and carbon dioxidec. oxygen and nitrogend. nitrogen and carbon dioxide

2. A spirometer is a device used to _____. a. measure heart rateb. measure blood pressurec. evaluate respiratory functiond. evaluate pulse

3. _____ is the process of moving oxygen in red blood cells from the lungs to the cells in the rest of the body and moving carbon dioxide back again. a. Ventilationb. Inspirationc. Gas exchanged. Gas transport

4. Maximal oxygen uptake is _____. a. not the same as VO2 maxb. unrelated to aerobic activityc. the least amount of oxygen that your body can use at the cellular leveld. the greatest amount of oxygen that your body can use at the cellular level

0203401LB02B-07-74

The Energy Equation

7-11

5. Which of the following does NOT stress your respiratory system? _____a. Smokingb. Altitudec. Talkingd. Exercise

6. An electrocardiogram measures _____ of the heart. a. the electrical conductivityb. only irregular patternsc. activity, not patternsd. the negative charge


Step 7: Guidelines for Cardiovascular ActivityWe’ve already outlined some of the changes that occur in the respiratory and cardiovascular systems when a person is performing aerobic exercise. They include:

● Increased maximum oxygen consumption

● Increased efficiency of oxygen uptake

● Increased maximal ventilation

● Decreased resting heart rate

● Increased heart volume

● Increased stroke volume, both during exercise and at rest

● Increased maximum cardiac output

● Increased capillary density

● Increased total blood volume

0203401LB02B-07-74


7-12

But try telling all of that to your clients. By themselves, these changes may be a bit hard to get excited about. So, let’s look at some of the implications of the changes to your body when you train aerobically. These are changes that your clients can actually see in the mirror, feel during their workouts and perceive in their doctor’s office. They include:

● Decrease in total body fat stores

● Lower blood pressure

● Lower total cholesterol and higher good cholesterol

● Increased capacity for aerobic activity

● Increased heart function

● Decrease in symptoms of depression, anxiety and overall tension

Furthermore, being aerobically fit decreases your risk of conditions and diseases, such as type 2 diabetes, colon and breast cancer, heart disease and even simple colds.

If those benefits aren’t exciting enough, aerobic training helps you sleep better. It can help you enjoy other activities, such as dancing the night away. It lifts depression. It ensures that you can fit into your jeans. It reduces the symptoms of PMS. It decreases your risk of getting injured during those impromptu volleyball games or golf matches. It increases your concentration, energy and stamina, which leads to a host of other advantages.

Now, those are benefits that should excite your clients! And here’s how your clients can become more fit.

Types of Aerobic ActivitiesPeople have an incredible number of choices for aerobic activity, ranging from relatively low-tech options, like walking, to activities that require more equipment, such as cycling. Let’s talk about some guidelines for popular activities. It’s important that you, as a personal fitness trainer, educate your clients about these guidelines.

Walking, Jogging, RunningLace up your shoes and head out the door—it doesn’t get any easier than that. Simplicity is a strong point for walking and related activities, in part because normal excuses don’t apply. On vacation or traveling for work? Get a new perspective on the area you’re in by going for a jog. Can’t get to the gym in time for a class? The streets are open 24 hours a day, seven days a week. Weather gets in your way? Go to the mall or hit the gym’s treadmills.

Almost anyone can reap health benefits from walking, particularly people who are 20 or more pounds overweight and those who have been sedentary for long periods of time. Usually, walking is less intense than jogging and running, so people can walk for longer periods of time with less risk of injury.

0203401LB02B-07-74

The Energy Equation

7-13

As you increase walking speed to approximately five miles per hour on flat terrain, the intensity of walking approaches that of jogging. We’ll talk more about intensity later in this lesson. In general, walking burns 50 percent to 60 percent of the calories that jogging does. Hilly terrain increases the intensity of walking, jogging and running.

For walkers, joggers and runners:1. Invest in appropriate footwear, including socks. Be sure footwear provides adequate

cushioning, heel support and flexibility.

2. Avoid injury by doing adequate warm-up and cool-down exercises and appropriate flexibility exercises. We’ll talk more about warming up and cooling down a bit later in this lesson.

3. Increase intensity gradually. Start by walking about two miles on flat terrain, and be sure your arms and shoulders are free to swing and your chest is relaxed to counter the swing that should happen in your pelvis. Add time to the walk before adding intensity. However, if time constraints are an issue, you can add intensity first. Walkers should aim for at least 20 minutes, preferably 30 or more minutes, per session. If jogging, start by alternating walking and jogging in 50-yard increments and limit each session to 25 or 30 minutes for the first two months. Again, gradually add minutes at a slower pace to each session before adding speed or incorporating hills.

4. Monitor exercise frequency. If you’re walking, watch for muscle soreness but walk as often as possible. Joggers and runners need more rest. Beginners should jog only every other day—no more than four days per week—to let the lower body recuperate. We’ll talk about frequency in a more in-depth manner shortly.

5. Do not carry music. This limits the free swinging of the arms, causes tightness in the chest and makes proper breathing difficult.

6. Allow the pelvis to swing naturally.

Swimming and Water ExerciseSwimming and other water-based aerobic activities provide excellent benefits for people who have joint problems or who have been injured doing some other activity. This is because the water buoyancy allows for free movement without the hindrance and extra stress of body weight. Swimming requires greater skill than some other sports; however, water exercise is usually performed while the body is upright in the water, requires relatively little skill and can provide an excellent cardiovascular workout.

When experienced swimmers work at a specific intensity, their heart rate stays relatively lower than it does for joggers who run at that same intensity. This may be because swimmers exercise in a prone position in cool water, which helps the body take care of heat generated while exercising. When you determine a target heart-rate range, keep in mind that lap swimmers’ targets may be up to 10 beats per minute slower than the target for a runner. You learned to calculate target heart rates in Lesson 4.

0203401LB02B-07-74


7-14

It may be difficult for unskilled swimmers to exercise very long without becoming excessively tired; however, they’re using more energy than more skilled, efficient swimmers. Still, performing other exercises in the water would provide more long-term benefits for people who prefer exercising in water but aren’t skilled swimmers or don’t want to invest the time to learn. Water exercises can be performed in shallow or deeper water; small life vests and other flotation devices, such as kickboards, can be used to regulate exercise intensity. Water exercises, such as walking through chest-high water, can be combined with swimming.

For swimming and water exercise:1. Check skill level. People must be able to swim with some skill before attempting swimming

as their cardiovascular exercise. Also look for aerobic classes at your gym or health club. These allow a person with little water experience get her heart rate up and work on many muscles throughout the body.

2. Find a pool that is maintained for exercise purposes. Generally, lap swimmers prefer cooler water than recreational swimmers. Water exercisers may prefer slightly warmer water than lap swimmers. For lap swimmers, the pool should be big enough that the swimmer spends enough time stroking between turns—20 yards is minimal, and 25 yards is even better.

3. Avoid injury. At each session, warm up, cool down and stretch.

4. Take advantage of interval training and combining water exercise with lap swimming to increase intensity appropriately.

Your Options are Endless!For people who don’t mind investing in equipment or gym memberships, many other aerobic exercise options are available. For any indoor exercise, consider having a fan available to help prevent overheating. Here are some of the more popular, time-tested methods.

Cycling, like swimming, offers cardiovascular benefits without the stress of weight-bearing exercises, such as running. Cycling outdoors can be a powerful incentive to finish exercise sessions—basically, you’re stuck on the bike until you get to your destination—while cycling indoors offers protection from inclement weather. Whether indoors or outdoors, adjust the seat to the appropriate height—the knee should be bent slightly at the bottom of the pedal’s cycle—and adjust the handlebars so that the rider leans slightly forward and is relaxed. Beginners should keep the pedaling speed constant, between 70 and 90 revolutions per minute per leg. Also be sure to warm up and cool down adequately. Outdoor cyclists may find cycling gear, such as toe clips for uphill climbs, and specialized apparel helpful in increasing their enjoyment for long sessions. Outdoor cyclists should always wear a cycling helmet.

Rowing machines improve not only cardiovascular fitness but also arm, back and thigh muscle strength and endurance. Most rowing machines provide options for varying intensity. You can also speed up or slow down the number of strokes per minute to increase or decrease intensity. You should begin at a relatively low intensity or low machine resistance, with eight to 10 strokes per minute for five to 10 minutes. Then, gradually add stroke speed to 15 to 30 strokes per minute, as well as duration, increasing to 15 to 30 minutes. We’ll talk about duration further later in this lesson. Increase intensity last, and be sure to monitor heart rate.

0203401LB02B-07-74

The Energy Equation

7-15

Traditional aerobic and step classes that provide at least 20 to 30 minutes of aerobic activity three or four times per week provide excellent cardiorespiratory benefits. In addition, they require relatively little investment other than a gym membership. The primary drawback is working a class into a busy schedule. Aerobic and step classes also require more coordination and motor skill than walking. Be sure that the class offers an appropriate level or range of intensity. For example, step aerobics tends to be more intense than a low-impact class. Beginners to step classes should start with step heights of four to six inches and a rate of 120 to 130 steps per minute, gradually adding step height to about eight inches after two months of training. Always ensure your heel is on the bench when stepping, and be sure to wear footwear that provides appropriate cushioning, support, flexibility and traction.

Stair machines and elliptical machines provide weight-bearing, low-impact exercise, which is good news for joints, ligaments and tendons, as well as bones. Beginners must pay attention to proper form so that they don’t support their body weight on the guard rails and so that their knees are protected. Interval training can be useful for beginners. Also, adequate warm up and cool down is necessary. Walking on a flat surface is better than even the lowest resistance setting on the machine, which may be too intense for beginners.

Handball, racquetball, tennis and many other sports may provide cardiovascular benefits depending on your skill level. Each sport requires muscular coordination and skill, and the cardiovascular benefits vary with skill level. As is the case with swimming, unskilled players use more anaerobic energy than aerobic energy. However, as skill level increases, it’s possible to maintain movement at an appropriate intensity to provide cardiovascular benefit.

FrequencySome guidelines for exercise frequency are included in the descriptions of each sport in the previous section; however, here are some overall recommendations.

Basically, frequency is the number of exercise sessions in a week. You should vary exercise frequency depending on the intensity of the exercise and the length of time or duration for which you’re doing it.

You should exercise at least three days per week with no more than two days between sessions to improve cardiovascular and respiratory fitness and maintain body fat at optimal levels. Some professionals recommend three to five days per week for aerobic programs. When someone begins an exercise program, eight weeks of exercising every other day is a good starting point. More than one shorter exercise session per day may be most appropriate for someone who is extremely unfit.

People who do weight-bearing exercises, such as aerobics, jogging or even walking, should allow 36 to 48 hours of rest between sessions. This rest period helps prevent overuse injuries and gives the bones, joints, ligaments and tendons adequate time to recuperate. The rest period is even more crucial for those who are overweight.

DurationExercise duration or time refers to the amount of time in an exercise session that aerobic conditioning is occurring, which means warming up and cooling down don’t count. The duration of the conditioning period may be as little as five minutes. It can also be 60 or more minutes depending on your goals and conditioning level.

0203401LB02B-07-74


7-16

The duration of exercise depends on the exercise intensity. We’ll discuss intensity and how to measure it in more detail in a moment. When you’re exercising at a given intensity, such as 60 percent of maximal oxygen uptake, you expend more total energy doing 15 minutes of the exercise than when you do 10 minutes of the exercise. Beginners and unfit individuals should start with 10 to 20 minutes of aerobic conditioning or even two five-minute sessions. People of average fitness should exercise for 15 to 45 minutes, while fit people can exercise from 30 to 60 minutes—and this is only the aerobic conditioning part of the exercise session, remember.

IntensityExercise intensity measures the workload or how hard the heart is working. We briefly addressed exercise intensity in Lesson 4. Exercise intensity is measured in two ways: by a percentage of maximum heart rate or a percentage of maximal oxygen uptake. Some organizations develop charts that list the relative intensity of individual exercises and the appropriate ranges for individuals, depending on age. These charts tend to be measured in METs.

In Lesson 4, we learned to compute maximum heart rate, target heart rate and perceived exertion as methods for measuring exercise intensity. To train at an intensity that will give you cardiovascular and respiratory benefits, you want to exercise at 40 percent to 85 percent of maximum oxygen uptake or 55 percent to 90 percent of maximum heart rate. That goal can be broken down further, depending on a person’s fitness level:

● Low fitness level—Training intensities of 40 percent to 50 percent of maximal oxygen uptake or 50 percent to 60 percent of maximum heart rate are beneficial.

● Healthy adults—Intensities of 60 percent to 70 percent of maximal oxygen uptake or 70 percent to 85 percent of the maximum heart rate are appropriate.

● Healthy, highly fit adults—75 percent to 85 percent of maximal oxygen uptake or greater than 85 percent of the maximum heart rate may be appropriate.

For health benefits, such as reducing total cholesterol, increasing HDL cholesterol and decreasing blood pressure, exercise at 40 percent to 60 percent of maximal oxygen uptake is sufficient.

As you and your client become more savvy in matching heart rate to her perception of how hard she’s working, monitoring whether she’s exercising at an appropriate intensity becomes less cumbersome. However, even when your client has a good sense of what intensity of exercise is appropriate, monitoring heart rate can be important. Day-to-day changes in diet, fatigue, emotional stress and weather may change the intensity of a certain exercise. For example, your client’s three-mile run at an eight-minute-mile pace was a breeze Thursday. However, that same course and pace Sunday, after Saturday night’s steak dinner, might push her out of her aerobic zone. Getting a pulse takes only a few seconds; therefore, take it!

FITT PrincipleTake a moment to think about what we’ve discussed in this section. We talked about the type of activity, frequency, duration or time and intensity. If you take the first letters of frequency, intensity, time and type, you spell FITT. Using these four items to create a workout program is called the FITT principle.

0203401LB02B-07-74

The Energy Equation

7-17

Step 8: Warm Up and Cool DownHave you ever been in the shower when the warm water suddenly runs out? Pretty awful, isn’t it? Or perhaps you found it invigorating. But would you call it pleasant? Chances are you set a speed record for rinsing and getting out. Would you want to stay there a long time? Probably not.

Exercising without warming up is sort of like suddenly being under an icy blast of water—not only is it unpleasant physically, it’s also unpleasant psychologically. However, many people don’t think warming up is necessary. That’s where you, the personal fitness trainer and nutritional specialist, come in! You’ll be able to teach your clients just how important a proper warm up really is.

Let’s discuss some of the physical benefits to warming up before starting an aerobic activity.

Warming up:gradually distributes the blood to active muscles.

improves the elasticity of connective tissue and muscles.

improves coronary blood flow in the early stages of the aerobic activity, which reduces the risk of heart attack.

gradually increases the temperature of the muscles, which reduces the likelihood of muscle injury.

allows oxygen consumption to increase gradually, which improves the overall use of oxygen in the training period.

lets any problems—an exceptionally sore or injured muscle, for example—become apparent before the intense aerobic time of the exercise session.

Warming up provides an important psychological benefit, too. It is a time in which you can make the mental transition to exercising. Gradually, you can focus on your upcoming aerobic session, which improves the alertness you bring to your workout.

Similarly, cooling down reduces the likelihood that muscles will spasm or cramp and prevents a rapid drop in blood pressure that can cause dizziness or fainting.

Once you’re in the habit of warming up and cooling down at each exercise session, you’ll come to know another reason to do them. They feel good!

Warm Up How-tosWarming up should gradually increase blood vessel dilation, heart rate, systolic blood pressure, oxygen consumption and elasticity of active muscles and joints. An effective warm-up session has two components: general and activity specific. That’s a fancy way of saying you need to move and you need to stretch.

The general warm up should include five to 10 minutes of movement. Some experts recommend slower movements of the aerobic activity you’ll be doing. For example, you might try some slow swimming to start off your session in the pool, or some slow cycling with low resistance before you increase the pace and intensity. Others recommend walking as a way to warm up for nearly any exercise. Another option is slow-tempo calisthenics. It all depends on your preference and abilities.

0203401LB02B-07-74


7-18

The activity-specific part of the warm up should focus mostly on the muscles to be used in the aerobic activity. For example, if you’re going for a run, you should stretch your calves, Achilles tendons and quadriceps after walking but before you take off running. Aside from stretching, you also can incorporate lower-intensity movements that are part of the aerobic activity, such as gently rotating the arm at the shoulder for a swimmer or volleyball player, for example.

Cool Your JetsSome people think the cool down is a waste of time—walking out to the car after a tough game of racquetball should be plenty of cooling down! Others treat post-exercise time as a sort of happy hour, plopping down on the grass after touch football with a cold beer.

The truth is that the cool down is as important as the warm up, and stretching is more important in the cool down because warm muscles respond better to stretching. Allowing the body to gradually slow down helps the muscles get rid of waste products, such as carbon dioxide and lactic acid, more efficiently than slamming on the exercise brakes.

The duration of the cool down should be in proportion to the duration and intensity of the aerobic activity—in general, another five to 10 minutes for a 30- to 40-minute aerobic session. The activities for a cool down, like those for a warm-up session, are really limitless. Walk, cycle slowly with no resistance, swim with a slower rate of arm stroke or even march in place at a gradually reduced speed and intensity. This will help your body recover from the hard work it’s done.

Step 9: Physiology of Energy ProductionEnergy is something that everybody understands at a very basic level. You know when you have it, and you know when you don’t! But where does it come from, where does it go and how can we get more of it?

Before we get to those questions, here’s some background information. In the fitness and nutrition world, energy is measured in kilocalories or kcal. A kilocalorie is the amount of energy required to raise the temperature of one kilogram of water one degree Celsius. Do you remember learning this about calories in Lesson 5? Well, the calorie count you read on food labels really refers to kilocalories. Yep, you guessed it—energy is related to food.

Energy RequirementsHow much energy do you need to get through the day? For an adult, your resting metabolic rate, or RMR, and your activity level influence your energy requirement. You should remember learning about these terms in Lesson 5. Environmental temperature, body composition, body size, age and genetics influence each of those factors. Genetics alone can cause energy requirements to vary by 10 percent to 20 percent. For children and adolescents, factor in growth as another variable.

Believe it or not, the energy your body consumes at rest is the largest part of your total energy expenditure—about 60 percent to 75 percent. Included in this figure is the number of calories it takes to keep you breathing, your heart beating and your body temperature within normal limits. Think of it! Just sitting causes you to burn calories. If your clients enjoy eating, that’s excellent news. In fact, the energy it takes to digest, absorb, metabolize and store a meal can account for another seven percent of your total energy requirement.

0203401LB02B-07-74

The Energy Equation

7-19

And there’s more good news. You can influence your RMR so that you burn even more calories while watching TV. If you increase your lean body tissue—the amount of muscle your body has—you’ll burn more calories naturally. Other factors that increase RMR include youth, fluctuations in the menstrual cycle and abnormally high body temperature, or hyperthyroidism, which is the result of an overactive thyroid gland. Decreased RMR can be due to loss of lean tissue, low intake of calories and hypothyroidism, which is the result of a low-functioning thyroid gland.

Physical activity accounts for the rest of your energy requirement. The number of calories you burn during physical activity depends on your own personal system, but it generally increases with the frequency, intensity and duration of your training program. Don’t forget all the activity you do that doesn’t count as aerobic conditioning. If you spend eight hours a day stocking supermarket shelves, you’ll burn more energy than if you spend eight hours a day typing data into a computer.

Your body weight helps determine your energy requirement. Remember, in Lesson 5 you learned that a person wanting to maintain her present body weight needs to take in the same number of calories that her body expends through RMR, physical activity and TEF combined. If your weight is going up or down, the equation is out of balance.

Some sports medicine and fitness organizations have developed estimates for daily calorie needs based on body weight and activity level. These charts provide a good starting point for estimating energy requirements, too.

ATP: Energy’s Building BlockLet’s do another quick review. As you learned in Lesson 4, the energy that drives muscle contraction comes from a substance called adenosine triphosphate, or ATP. ATP is produced from the glucose in the muscle cell. Although cells can store some small amounts of ATP, a working muscle uses up the stores quickly—in two to three seconds. Therefore, the rate at which a muscle produces ATP determines how much energy that cell can produce before it is tired.

As part of the process of supplying energy to active muscles, ATP is converted to ADP, which is a lower compound that can be reconverted into ATP. If the muscles aren’t working too hard, the cell’s mitochondria use oxygen to regenerate ATP from ADP. The mitochondria oxidize fuel in the forms of carbohydrates, fats and proteins, to produce energy, yielding carbon dioxide and water as by-products of the process.

However, if the activity lasts a longer period of time and is at a certain level of intensity, the aerobic system can’t keep up with the demands for ATP. At this point, the body uses different methods for producing energy. We’ll take an in-depth look at anaerobic energy systems later in this lesson.

Using Energy: How Do Muscles Do It?When you exercise aerobically, your muscles have the energy to contract because ATP is present in your system. You can keep going comfortably as long as your body can keep up.

When you exert your muscles for a high-intensity activity, such as lifting a weight for a very short time, your muscle is tired because the cells run out of ATP at the part of the muscle that controls muscle contraction. The fibers of the muscle have no energy and can’t contract. When you exercise heavily for a longer period of time the muscles get tired because lactic acid, a byproduct of anaerobic methods for producing energy, accumulates in them.

0203401LB02B-07-74


7-20

Usually, any excess lactic acid that your body produces while exercising clears from the muscles within about an hour after you stop. Some of the lactic acid is metabolized in the muscle cell, and some goes to the liver. Your clients’ muscles may be tired and feel sore while exercising because this lactic acid is irritating nerve endings, but they will feel better later.

When you exercise for an hour or longer, the fatigue your muscles feel is from the lack of glycogen. Glycogen is glucose in its stored form, and you probably remember learning about glycogen and its importance to the body in Lesson 6. If you’ve tried an endurance activity, such as running a marathon, and “hit the wall,” you’ve experienced glycogen depletion. You may have plenty of oxygen in your system, but without glycogen, it doesn’t matter.

Using Fats, Carbohydrates and ProteinsAerobic activity burns primarily carbohydrates and fats to produce ATP. Except in long-term starvation or extra-long endurance activities, protein isn’t metabolized significantly. You learned this in Lesson 6. However, the human body is one efficient machine. It adjusts to take advantage of the available sources of energy.

In Lesson 6, you also read that when an athletic body is at rest, about 30 percent of the ATP that it’s producing comes from carbohydrates, and about 70 percent comes from fats. Even in untrained people, 50 percent of ATP produced at rest comes from fatty acids. When you start exercising and the intensity of the exercise grows, the body shifts to use mostly carbohydrates and less fat as the source. When you’re exercising at a high intensity—anaerobically—nearly 100 percent of the ATP is produced from carbohydrates. But when you’re exercising aerobically at a submaximal intensity, the body shifts back to using more fats.

You already know that the types of carbohydrates are basically sugars; they are either in the form of glucose or in another form of sugar that rapidly can be converted into glucose. Glucose in the blood and glycogen undergo a process called glycolysis. Glycolysis is the breakdown of glucose and glycogen that releases energy in the form of ATP. When your cells have enough oxygen and produce energy aerobically, the byproduct of glycolysis is used to produce more energy. When your cells don’t have enough oxygen, the byproduct of glycolysis is lactic acid.

Proteins normally aren’t used to produce energy for short-term activities. However, proteins can be broken down into amino acids, which then are converted into glucose or other elements. During very long-term activity, amino acids may contribute from three percent to 18 percent of the energy requirements for your muscles.

Step 10: The Importance of Anaerobic Threshold, Glycogen and Creatine Phosphate

Aerobic, aerobic, aerobic—we’ve talked a lot about it so far, and you’ll hear more about aerobic training than anaerobic training at the gym. But it’s important for personal fitness trainers and nutritional specialists to know how the anaerobic energy production system works, too.

After a period of aerobic exercise, you eventually reach the anaerobic threshold. At that point, the anaerobic systems for producing energy kick in.

0203401LB02B-07-74

The Energy Equation

7-21

As previously mentioned, although glucose in the bloodstream and glycogen stored in the liver and muscles are used in the aerobic production of energy, the body also uses them without oxygen to produce energy anaerobically.

In Lesson 4 you learned that the body also can use creatine phosphate to produce ATP anaerobically; however, the body doesn’t store very much creatine phosphate. In fact, some studies show that the amount of combined ATP and creatine phosphate stored in the body is enough for only about 10 seconds of maximal effort. On the up side, creating ATP from creatine phosphate is a very fast process, so if you’re doing an anaerobic exercise of about 30 seconds, you’re probably running on creatine phosphate.

Still, for anaerobic activity longer than 30 seconds, the anaerobic system relies primarily on glucose to produce ATP. Remember, a byproduct of anaerobic glycolysis is lactic acid, along with heat and hydrogen ions. Lactic acid buildup equals irritated, sore muscles.

If you do some anaerobic activity, such as lifting weights, cooling down with some light aerobic activity is important. It helps carry oxygen to the muscles, which are depleted, and it helps move the blood through your body, which carries away lactic acid.

Before we finish this lesson, let’s pause for a moment. Use the following Practice Exercise to review what you’ve learned.

Step 11: Practice Exercise 7-2Select the best answers from the choices provided and write your answers on scratch paper.

1. _____ provide(s) excellent benefits for people who have joint problems or who have been injured doing some other activity. a. Elliptical machinesb. Joggingc. Water-based activitiesd. Volleyball

2. Generally, lap swimmers prefer _____ recreational swimmers. a. water the same temperature as dob. to swim in the same lanes as doc. warmer water thand. cooler water than

3. Stair machines and elliptical machines _____.a. provide weight-bearing, low-impact exerciseb. do not offer much intensity rangec. are bad for the jointsd. should never be used by beginners

0203401LB02B-07-74


7-22

4. Duration refers to _____.a. the number of exercise sessions in a weekb. the amount of time in an exercise session that aerobic conditioning is occurring, including

warming up and cooling downc. the amount of time in an exercise session that aerobic conditioning is occurringd. how hard the heart is working

5. _____ you can make the mental transition to exercising. a. During warm upb. During cool downc. While intensely working outd. While lifting weights

6. Cooling down _____.a. increases the chances of a rapid drop in blood pressureb. reduces the likelihood that muscles will spasm or cramp c. sometimes causes faintingd. commonly causes dizziness

7. Your muscles may be tired and feel sore while exercising because _____ is irritating nerve endings. a. ATPb. lactic intolerancec. lactic acidd. amino acid


Step 13: Lesson SummaryThe human body is amazing. From materials, such as invisible gases, it produces the energy that lets us perform an infinite variety of tasks—vacuuming, throwing a ball for the dog and smiling at a neighbor. In this lesson, you learned how oxygen gets to the muscles so that they can produce energy, as well as how the cardiovascular and respiratory systems respond to exercise. We talked about the guidelines for cardiovascular activity and discussed how intensity, duration and frequency influence the effectiveness of aerobic exercise. You will also be able to teach your clients the importance of warming up and cooling down. Lastly, we discussed how energy is produced aerobically and anaerobically.

0203401LB02B-07-74

The Energy Equation

7-23

In the next lesson, we’re going to talk about anatomical terms and locations. Understanding anatomy will be key in your new career. After all, personal fitness trainers and nutritional specialists must have knowledge of how the body works if they hope to educate their clients. But before you move on to your next lesson, reread any parts of this lesson that you found confusing. Now is the time to contact your instructor with questions! Once you are confident that you understand what you’ve read here, tackle your final quiz and apply what you’ve learned.


0203401LB02B-07-74


7-24

Lesson 8Anatomical Terms and Locations


● Explain the basic components of human biology.

● Identify and describe the different planes and sections of the human body.

● Define the terms used to describe movements of the body.

Step 2: Lesson Preview In the 15th century, when Leonardo da Vinci drew his sketches of the human body, he probably didn’t anticipate just how important the study of the human body would become.

Today many people use anatomy in their professions. Athletic coaches and fitness trainers who are well versed in anatomy use their knowledge of muscles and bones to help their players and clients achieve top performance. Doctors must know anatomy in great detail, from the top of the head to the little toe, and all the nerves, blood vessels and organs in between.

As a personal fitness trainer and nutritional specialist, you will use your knowledge of the human body to help provide accurate assessment and fitness prescriptions to your clients. In this lesson, you’ll begin to understand anatomy in the context of your daily life and how you will use this knowledge in your fitness training practice.

Step 3: What Is Human Biology?In this course, you’ll learn about the study of human anatomy and physiology as it relates to fitness and wellness. Because you’re human, you’ll be learning a lot about yourself! You’ll grow in your understanding of the human body and the specialized terms that health professionals use to talk about the body.

Human biology is the study of how the body is put together and how it works in health and disease. While you don’t need to become an expert in biology, an understanding of biology, anatomy and physiology basics will provide you with a solid foundation for the more in-depth anatomy that you’ll learn later in your course.

Human biology in the healthy state includes two basic concepts: anatomy and physiology. Human biology in

0203401LB02B-08-74


8-2

disease deals with pathology. Look at the following illustration to see how these concepts are related:

Biology deals with health and disease.

We’ll discuss each of these topics in more detail. Remember, your goal is not to become an expert in biology, but to understand the basic terms and concepts that will be useful in your career as a fitness professional.

AnatomyAnatomy is the science of the structure of the body—the structure and relationships of body parts. The two divisions of anatomy are gross anatomy and microscopic anatomy.

● Gross anatomy—also called macroscopic anatomy—includes parts of the body that can be studied without a microscope.

● Microscopic anatomy, or cell anatomy, includes parts of the body that have been revealed by a microscope.

The two divisions of anatomy are gross anatomy and microscopic anatomy.

0203401LB02B-08-74

Anatomical Terms and Locations

8-3

Gross AnatomyIn gross anatomy, we are concerned with the presence and structure of a body part.

The study of the form of body parts is called morphology. The form of a body part includes its size, shape, color, contour and texture. For example, when a kidney is normal in size, shape, color, contour and texture, we say it has normal morphology.

A basketball player and a jockey both have the same anatomical structure. For example, they both have five fingers on each hand. However, there is a morphologic difference between them. For example, the hand of the basketball player is larger than the hand of the jockey.

The terms used to describe gross anatomy include:

● The names of body parts

● The location of body parts

● The relationship between the locations of body parts

Gross anatomy also deals with the location and position of the organs and body parts. For example, not only should the heart be in the chest, but it should also be in the left side of the chest.

Microscopic AnatomyMicroscopic anatomy is the science of the body’s individual cells and tissues. We use a microscope to study this kind of anatomy. As a personal fitness trainer and nutritional specialist, you will not learn details of microscopic anatomy.

PhysiologyYou already know that physiology is the study of how the body works; it describes the function of the body and its organs, tissues and cells. Each organ, cell or tissue has its own special physiological function. For example, kidneys filter blood, but they cannot think. The brain thinks, but it cannot filter blood.

We also can divide physiology into macroscopic physiology and microscopic physiology.

● Macroscopic physiology is usually called gross physiology.

● Microscopic physiology is usually called cell physiology.

Step 4: PathologyPathology is the study of human biology when anatomy and/or physiology have become abnormal. Some diseases and pathological conditions are contraindications to exercise or certain types of exercise. This means some clients cannot perform certain exercises in particular regions of the body, depending on the condition.

Now, let’s take a minute and review what you’ve learned so far.

0203401LB02B-08-74


8-4

Step 5: Practice Exercise 8-1Using words from the following list, complete the blanks in the sentences using your own paper. Not all terms will be used.

morphology anatomy pathologicalpathology biology gross anatomyphysiology morphological assessment

1. Anatomy, physiology and pathology are included in the study of life called human _____.

2. When there are changes in the form of an organ, such as size, shape or color, they’re called _____ changes.

3. The science of the structure and relationships of body parts is called _____.

4. The study of the function of body parts is called _____.

5. The study of disease is called _____.

Step 6: Review Practice Exercise 8-1Check your answers with Answer Key at the back of this book. Correct any mistakes you may have made.

Step 7: The Anatomical PositionNow that you have a basic understanding of what human biology is about, you’re ready to move on to the more specific science of anatomy and physiology. As a personal fitness trainer and nutritional specialist, you’ll often refer to various anatomical regions of the body.

Personal fitness trainers, healthcare practitioners and biologists use a system to describe the location of anatomical parts. This system assures that there is no confusion about the location of any parts, even if the client is hanging by the feet doing yoga.

The location of body parts is always described as if the patient were in the position shown here. This body position is called the anatomical position.

0203401LB02B-08-74


8-5

Anatomical Position

Notice the position of the hands in the figure. The palms are facing forward, and the thumbs are facing outward. No matter what the position of the client, the personal fitness trainer will describe the location of anatomical parts as if the client were always in this position.

Now, stand up and put your body in the anatomical position. Focus on how this position feels to you and keep a picture of it in your mind as you study the rest of this lesson. All the terms you’ll learn in this lesson are based on the relationships of body parts when the body is in this position.

Step 8: Planes and Sections of the Human Body The human body has three dimensions: height, width and depth. As we talk about human anatomy and physiology, you’ll find it helpful to refer to different portions and sections of the body. You will need to know and understand these references in your work as a personal fitness trainer.

To identify portions, you can refer to the body in different ways:

● Top and bottom portions

● Right and left portions

● Front and back portions

● The location of body parts

● The relationship between the locations of two body parts

0203401LB02B-08-74


8-6

Dividing the body like this can help you understand and remember where organs or parts are located. You can divide the body into these portions by making a mental slice or cut. This slice or cut is called a section. Sections occur along planes. Planes are imaginary flat surfaces that divide the body into parts.

There are three basic body sections:

● A transverse section divides the body into top and bottom parts.

● A sagittal section divides the body into right and left parts.

● A coronal section divides the body into front and back parts.

Transverse Sections and the Transverse PlaneThe transverse plane or horizontal plane divides the body into top (superior) and bottom (inferior) portions. A section made along the transverse plane is called a transverse section. We refer to transverse sections anywhere in the body from the bottom to the top. Look at these examples:

● A transverse section at the neck divides the body into top and bottom portions. The head is above the section. The chest, arms, abdomen and legs lie below the section.

● A transverse section at the waist also divides the body into top and bottom portions. The head, chest and arms are above the section. The pelvis and legs are below the section.

● A transverse section at the level of the knees divides the body into top and bottom portions, too. The thighs, abdomen, chest, arms and head are above the section. The calves and toes are below the section.

Transverse sections

0203401LB02B-08-74


8-7

Sagittal Sections and the Sagittal PlaneA sagittal section, also called a longitudinal section, divides the body into right and left parts. A sagittal section occurs along a vertical plane, as the drawing shows. If a sagittal section divides the body into equal right and left halves, then we call it a midsagittal or median section. The midsagittal section is the midline of the body. We can identify a sagittal section made at any point of the body, from the left side to the right. A parasagittal section divides the body into unequal left and right sections.

Midsagittal and parasagittal sections

Coronal Sections and the Coronal PlaneA coronal section, also called a frontal section, divides the body into anterior (front) and posterior (back) portions. We can identify coronal sections at any point from the front of the body to the back of the body.

A coronal section at the level of the ears divides the body into front and back halves. The face, abdomen and knees are in front of the section. The back, buttocks and ankles are behind the section.

0203401LB02B-08-74


8-8

A coronal section made at the level of the nose divides the body into front and back portions. The nose is anterior to or in front of the coronal section. Everything else is posterior or behind.

Coronal sections

You can divide the body and each organ using any of the sections. For example, a midsagittal section of the liver would divide the liver into two equal left and right halves.

Study the definitions of these sections until you can form a mental image of them. You can remember these concepts more easily if you picture the planes using your own body as a guide. Complete the following Practice Exercise to review what you’ve read.

0203401LB02B-08-74


8-9

Step : Practice Exercise 8-2Using words from the following list, complete the blanks in the sentences using your own paper. Some terms will be used more than once. Not all terms will be used.

horizontal coronal longitudinalmidsagittal transverse slice or cutanatomical position frontal medianparasagittal sagittal

1. When the arms are at the side, the palms of the hands are facing forward and the thumbs are pointing outward, the body is in the _____.

2. A _____ section is also called a horizontal section.

3. A _____ section divides the body into unequal left and right portions.

4. A frontal section is also called a _____ section.

5. A _____ section divides the body into superior and inferior portions.

6. A longitudinal section is also called a _____ section.

7. A _____ section divides the body into anterior and posterior portions.

8. A _____ section divides the body into equal left and right portions.

9. A midsagittal section is also called a _____ section.

10. A section is a mental _____.

Step 10: Review Practice Exercise 8-2Check your answers with Answer Key at the back of this book. Correct any mistakes you may have made.

Step 11: Anatomical Parts and LocationsWhen personal fitness trainers and nutritional specialists describe the location of anatomic parts, they use terms that relate the location of one part to another part. Various terms describe the relative locations of body parts and organs. These terms rely on the anatomical position and the anatomical sections you just learned.

Anatomical location terms usually occur in antonym pairs. Each word of an antonym pair means the opposite of the other word; for example, above and below, or left and right.

0203401LB02B-08-74


8-10

If you draw a transverse plane through the body or an organ, these words describe anything above or below that plane.

● Superior means above.

● Inferior means below.

● Cephalad means toward the top of the head.

● Caudad or caudal means toward the tail or in the opposite direction from the head. So, in terms of the human body, caudad means toward the feet.

Transverse plane

Keep in mind that you will always use the anatomical position as the reference point for anatomical locations. For instance, the head is always superior to the shoulders, even if your client is standing on his head! This is because in the anatomical position, the head is above or superior to the shoulders.

0203401LB02B-08-74


8-11

If you draw a sagittal longitudinal plane through the body or an organ, these words describe anything closer to or farther away from that plane.

● Medial means closer to the sagittal plane or midline.

● Lateral means farther away from the sagittal plane or midline.

Sagittal plane

0203401LB02B-08-74


8-12

Another example using the anatomical position as the reference point is that the thumb is always lateral to the little finger, even though your client can stand with the thumb closer to the midline.

If you draw a coronal or frontal plane through the middle of the body or an organ, these words describe anything in front of or behind that plane.

● Anterior means in front of.

● Posterior means in back of.

● Ventral means on the belly side.

● Dorsal means on the back or spine side.

Coronal plane

0203401LB02B-08-74


8-13

Using the anatomical position as a reference point again, the palms are always anterior to the back of the hand.

Look at some examples of how to use these words. To help you apply the terms, compare these statements to your own body positions and location of parts. Be sure your body is in the anatomical position when you match the statements with your own body’s structure.

● The right thumb is lateral to the right little finger.The right little finger is medial to the right thumb.

● The chest is cephalad to the knee.The knee is caudad to the chest.

● The chin is anterior and superior to the heel.The heel is posterior and inferior to the chin.

● The navel is medial and anterior to the elbow.The elbow is lateral and posterior to the navel.

Sometimes, you will need to describe the position of a body part relative to where it is within the body as a whole. The following terms are used in those situations. Examples of how to use these words follow the terms.

● Proximal means nearer to the center of the body or organ or nearer the root of a limb. For example, the shoulder is proximal to the hand. The knee is proximal to the foot.

● Distal means farther away from the center of the body or organ or root of a limb. For example, the hand is distal to the shoulder. The foot is distal to the knee.

● Superficial means on or closer to the skin or surface of an organ. For example, the calf muscle is superficial to the calf bone. The skin is superficial to the muscles.

● Deep means under or farther away from the skin or surface of an organ. For example, the heart is deep to the ribs. The muscles are deep to the skin.

● Central means within or near the center. For example, the heart is central within the rib cage.

● Peripheral means at or near the rim or edge. For example, you can easily see the peripheral veins of the arms and hands.

● External means outside or closer to the skin or surface of an organ. For example, the scalp is external to the skull. Sometimes external is used synonymously with lateral. For instance, lateral rotation and external rotation refer to the same body movement.

● Internal means inside or farther away from the skin or surface of an organ. For example, the lungs are internal to the ribs. Sometimes internal is used synonymously with medial. For example, internal rotation and medial rotation refer to the same body movement.

0203401LB02B-08-74


8-14

The following terms describe whole body or body part positions. These terms can be used when the body is in any position, not just the anatomical.

● Prone means the body or body part is facing down.

● Supine means the body or body part is facing up.

The hand can be in a prone or supine position, as can the feet. Although it’s a bit of a gymnastics exercise to put your feet into the supine position—try it!

Before we talk about joints and connective tissues, let’s do a quick review.

Step 12: Practice Exercise 8-3Match the correct meaning to the location terms.

1. anterior a. within, insideb. toward the middlec. in front ofd. farther away from the centere. outer, outsidef. belowg. nearer to the centerh. at or near the edgei. in back ofj. above, upward

2. posterior

3. distal

4. external

5. inferior

6. proximal

7. internal

8. superior

9. medial

10. peripheral

Step 13: Review Practice Exercise 8-3Check your answers with the Answer Key at the back of this book. Correct any mistakes you may have made.

0203401LB02B-08-74


8-15

Step 14: Joints and Connective TissuesWith every move your body makes, your joints work hard to allow that move to happen. Joints are areas where bones come into close contact with one another. They are formed by two articulating bones, which means that the bones fit into each other to form a joint. Depending on the way the bones fit, the joint allows particular actions and not allow others. For instance, you easily can bend your elbow in an anterior direction, but you can’t bend it the other way. And your elbow joint extends or straightens easily, but it won’t move sideways. These are qualities of a hinge joint, which we’ll discuss a little later in this section.

Joints allow the human body to make thousands of combinations of movements. The most easily recognized joints are those that allow movement of different parts of your body, such as the joints in your hips, knees and elbows. However, not all joints are designed to allow the same range of movement. The different types of joints in our bodies are generally classified by the type of connective tissue in the joint and how much movement the joint allows:

● Fibrous joint. This class includes all joints where dense, fibrous connective tissue join the surfaces of the bones. These joints basically cannot move. An example of a fibrous joint is a suture, or junction, that is found between plates of bone in the skull. These joints in the skull allow for growth, but fuse at maturity to provide protection for the brain.

Fibrous joint in skull

● Cartilaginous joint. Fibrocartilage, a tough, rubbery tissue consisting of dense fibers, joins bones in this class of joint. Cartilaginous joints allow for slight movement. Cartilaginous joints connect the pubic bones of the pelvis and the intervertebral disks between bodies of vertebrae.

Cartilaginous joint

0203401LB02B-08-74


8-16

● Synovial joint. Synovial joints are also known as freely moveable joints. Most of the joints in the body, including the hip and shoulder, are in this class and are designed to allow a specific range of motion. Synovial joint cavities contain several different types of connective tissues.

Synovial joint

Synovial Joint ClassificationsTake a moment to get up and move about. First, with your hand in the supine position—face up—crook your finger as if you’re asking someone to come toward you.

Feel those joints moving? Those are hinge joints; they work like a door hinge that swings in and out.

Now, lift your arm and move it around in a circle. The joint in your shoulders that allows this movement is called a ball and socket joint.

Let’s take a moment to overview the six types of synovial joints, so you get a better understanding of the mechanisms that allow us to move.

● Hinge joint—Allows movement in one plane, changing the angle of the bones at the joint. Example: Elbow and ankle joints.

● Plane or gliding joint—Bone surfaces slide over each other. Example: Hand and spinal joints

● Condyloid or ellipsoid joint—Allows movement in two planes.Example: Knuckle and wrist joints.

● Pivot joint—Allows rotation within the joint.Example: Joint between first and second vertebrae

● Saddle joint—Allows movement in two directions—like a ball and socket except with limited rotations—but with deeper articulating surfaces.Example: Thumb joint

0203401LB02B-08-74


8-17

Synovial joints are incredible mechanisms; they allow our bodies to move in a variety of ways. But if bones move against other bones, what keeps them from wearing down or squeaking like your car brakes do when you need new brake pads? The answer is connective tissue, which lubricates, stabilizes and protects the joints. Fibrous connective tissue, which we’ll look at in more depth in the next step, supports synovial joints.

Connective TissuesConnective tissue is the supporting fabric of the body. There are many types of this in our bodies—from adipose or fatty tissues that support our eyeballs to cartilage that supports our external ear. Let’s examine these connective tissues:

● Cartilage: Even though bones articulate, bone rubbing against bone is not a good thing. Hyaline cartilage is a rubbery, smooth tissue that coats the ends of articulating bones, shaping them for an exact fit and protecting the bony tissue. It also absorbs impact just like a rubber bumper when our bones are jarred. And though we don’t think about it, our bones are jarred all the time. Have you ever had someone step on your foot? Then you know how much force your own foot has to absorb again and again while you walk. The cartilaginous protection of the bones is essential.

Cartilage is also found in other places in the body besides the ends of bones. For instance, the external part of your ears is composed of elastic cartilage. Also, there are two crescents of fibrocartilage in the knee that provide further shock absorption for the knee joint. In your work as a personal fitness trainer and nutritional specialist, you’re likely to encounter injured knee joints.

● Joint capsule: A joint capsule of tough tissue that has an extraordinary membrane on its inner side surrounds the entire synovial joint. This membrane makes synovial fluid, a lubricant that squeezes in and out of the cartilage every time we move our joints. As it squeezes, it nourishes the cartilage. And the lubricant is better than anything science can duplicate. Synovial fluid fills the joint space inside the joint and covers the smooth surface of the cartilage, bringing friction inside the joint to almost nothing.

● Ligaments: Since the articulating bones have a joint space between them, and since the joint capsule isn’t quite strong enough to hold the joint together—and you don’t want the capsule to tear and leak that wonderful synovial fluid—something more is needed to connect the bones to each other. Ligaments connect bone to bone at the joints and help restrict range of motion or ROM. Ligaments are very strong—fiber for fiber, as strong as steel. When you try to bend your elbow backwards and it won’t go, it is the ligaments of the elbow joint that are keeping your elbow straight. If those ligaments tear, the elbow can actually bend backward a little before the shape of the bones make the movement stop. So ligaments protect the stability of joints. When a ligament tears, you actually hear it snap. And a torn ligament is a worse injury than breaking a bone because ligaments have low blood supply and don’t heal very well once they’re injured.

● Periosteum: Periosteum is a membrane that covers the outside of the bone except at the joint. This membrane also delivers nutrients to bones and provides an anchor for ligaments. If you’ve ever banged your shin into the night stand in the middle of the night, the resulting pain came partially from the many nerve fibers of the periosteum.

0203401LB02B-08-74


8-18

● Bursa: A bursa is a small capsule filled with synovial fluid that protects tissues that would otherwise get too much friction. When inflamed, you actually can feel the bursa.

Some of the bursae of the knee joint (side view)

● Tendons: Tendons are tough, fibrous connective tissues that connect muscles to bones.

● Fascia: Fascia is net-like connective tissue that wraps our organs and muscles, supporting them and giving them their shape. Although structured to be tough, fascia is designed to allow free and easy movement.

You’ve probably seen the marbling on a steak. This marbling is the combination of fat and fascia that supports the meat and holds it together. If you look closely, you’ll notice that fascia is abundant on the meat. In our bodies, fascia is just as prevalent.

Have you ever noticed how soft and smooth an infant’s muscles feel? While you can feel the subtle shape of an infant’s muscle, the muscle still feels a little like Jell-O. In infants, fascia is free fascia because it does not bind in any way. This is why babies can suck their toes with little effort! But as we age—or if we overuse or misuse our muscles—fascia becomes thicker and begins to bind muscle cells, which interferes with the blood supply to those cells. Eventually, the affected muscle cells are replaced with fibrous connective tissue and cannot be rehabilitated. This condition is called fibrosis.

Now that you have a basic understanding of the types of joints and tissues in our bodies, let’s take a look at the actual movements that these wonderful mechanisms allow us to do.

Step 15: Movements of the BodyPicture a professional dancer or other athlete in action. Her movements illustrate the powerful, graceful and complex movements of which the human body is capable. All humans, athletes or otherwise, perform countless coordinated movements throughout their lifetimes. These movements occur at the synovial joints. And each synovial joint is designed to perform specific movements—or has a specific ROM.

0203401LB02B-08-74


8-19

Range of Motion or ROMAs a personal fitness trainer and nutritional specialist, you’ll often work with a client’s range of motion. As you know, each synovial joint performs a particular ROM. For instance, the elbow joint can only bend and straighten—flex and extend—whereas the shoulder joint can raise, lower, open wide, hold close and roll around. In other words it can flex, extend, rotate, abduct, adduct and circumduct—all terms you’ll learn in the next section.

There are two types of ROM. Active ROM is a motion you can do yourself just by telling yourself to do it. For instance, you know your favorite book is at the top of the stairs, so you decide to walk up them to get your book. For people with unrestricted ROM, this movement requires only the thought and initiative to move one foot in front of the other.

Passive ROM, on the other hand, occurs when someone or something else moves a joint. For example, you can bend your wrist backwards by telling yourself to perform this active ROM. However, if you apply pressure to further hyperextend the wrist, you are performing a passive ROM that cannot be achieved without the added pressure of your other hand.

The interaction between synovial joints and muscles is what allows us to dance, play, work and even bend over to pick up a penny! When ROM is restricted, people’s lives are restricted. Helping to restore a person’s ROM—and therefore improve the quality of his or her life—can be a big part of the satisfaction of being a personal fitness trainer.

Classifications of MovementsWe know that joints are classified broadly by the type of connective tissue and amount of movement allowed. Similarly, movements themselves are classified into categories based on the type and location of the body movement. As you read about each movement, perform the movement yourself. Can you feel the joint where the movement originates?

Flexion is movement that bends a joint so that the angle between two body parts is decreased and the parts come close together. This movement and its opposite, extension, take place along the sagittal plane.

Extension is the opposite of flexion. Extension causes the parts at the joint to straighten or open so that the angle between the body parts is increased and the parts move farther apart.Adduction of a joint brings a body part closer to the midline of the body or the midline of the hand or foot in the case of fingers or toes.

Abduction is the opposite of adduction and moves a body part away from the midline of the body or midline of the hand or foot along the coronal plane or sideways. Abduction of the fingers and toes involves spreading them apart. Remember that abduct generally means carry away. Both adduction and abduction pertain only to the appendages. For instance, the arm or upper limb is an appendage of the torso, and the hand is an appendage of the upper limb.

Rotation is the turning movement of a bone around its own long axis and involves movement in the transverse plane. Turning your head while driving a car is an example of simple rotation.

0203401LB02B-08-74


8-20

Medial rotation or internal rotation is an inward or internal movement of a body part toward the midline of the body.

Lateral rotation or external rotation is the opposite of medial rotation and causes an outward or external movement of the body part away from the midline of the body. Medial and lateral rotation occur at the shoulder and hip joints and passively in other joints.

Circumduction is movement of a body part so that its end follows a circular path. It is a combination of extension, adduction, flexion and abduction and occurs in the shoulder and hip joints and in the thumb, knuckles and wrist. It also occurs passively in the toe joints. An example of circumduction is the shoulder movements involved in rowing or paddling.

Lateral flexion is a movement of the head or trunk sideways from the midline of the body. This movement is sometimes known as side bending.

Pronation involves turning the hand so that the palm faces down.

Supination involves turning the hand so that the palm faces upward and is in a supine or face-up position. An easy way to remember this is that your palm would be in a supine position to carry a bowl of soup!

Opposition occurs when the thumb pad moves toward and touches other anterior pads of the fingers. This is the only location where opposition occurs.

Inversion occurs when the foot moves medially so the sole faces inward or if the foot is positioned so toes turn inward.

Eversion involves turning the foot laterally so the sole faces away from the body or if the foot is positioned with toes splayed out. Both inversion and eversion involve several joints of the foot.Plantar flexion is the movement at the ankle joint that occurs when the toe is pointed. For instance, when the foot is stepping on an accelerator pedal in a car, the ankle is in a plantar flexion movement. Ballerinas and gymnasts frequently have their feet in a plantar flexion movement.

Dorsiflexion involves upward flexing of the foot at the ankle, such as when you let off the accelerator in a car and the toes move toward the shin. Both plantar flexion and dorsiflexion occur only at the ankle.

Protraction refers to moving a body part anterior or forward in the transverse plane so that it sticks out.

Retraction occurs when a body part moves posterior or backward in the transverse plane so that it pulls back. Both protraction and retraction pertain to the shoulder blade, head and jaw.Elevation is movement superiorly or upward along the coronal plane. You can elevate your shoulders by lifting them.

Depression is movement inferiorly or downward. You can depress your shoulders by letting them sag.

Gliding is a movement that occurs when the bones of a joint slide across each other. Sometimes it occurs with a lot of motion, like when the jaw glides back and forth. Other times, gliding occurs with only a minimal motion. For instance, when we hold items with our hands, the small bones of the wrist and hand slide slightly.

0203401LB02B-08-74


8-21

Wow! You’re almost ready to take your final quiz. But first, complete the following Practice Exercise to review what you’ve learned. And remember, though you won’t use all of this terminology in your daily work, it’s important for you to have some understanding of joints and connective tissues, as well as how the body moves. Don’t forget to call your instructor if you have questions!

Step 16: Practice Exercise 8-4Using the words from the following list, complete the blanks in the sentences using your own paper. Not all terms will be used.

extension adduction supination cartilaginous jointflexion depression synovial joint circumductionopposition eversion retraction lateral rotationfibrous joint

1. The _____ is the most common type of joint in the body. The hip and shoulder are in this class and are designed to allow a specific range of motion.

2. The _____ type includes all joints where the surfaces of the bones are in almost direct contact and are not moveable.

3. _____ is movement of a body part so that its end follows a circular path. It is a combination of extension, adduction, flexion and abduction and occurs only in the shoulder and hip joints.

4. The _____ allows only slight movement.

5. _____ involves turning the hand so that the palm faces upward.

6. _____ occurs when the thumb pad moves toward and touches other anterior pads of the fingers.

7. _____ involves turning the foot laterally so the sole faces away from the body.

8. _____ occurs when a body part moves posterior or backward in the transverse plane.

9. _____ is movement inferiorly or downward.

10. _____ is the opposite of flexion and causes the parts at the joint to straighten out or open so that the angle between the body parts is increased and the parts move farther apart.

Step 17: Review Practice Exercise 8-4Check your answers with the Answer Key at the back of this book. Correct any mistakes yo may have made.

0203401LB02B-08-74


8-22

Step 18: Lesson SummaryThis lesson brings you along in your journey to become an effective and professional personal fitness trainer and nutritional specialist. Anatomy is an integral part of every aspect of fitness, and now you recognize many important terms.

This lesson explained the basics of human biology—the study of how the body is put together. Human biology in the healthy state includes anatomy and physiology. Human biology in disease deals with pathology. Anatomy is the science of the structure of the body—the structure and relationships of body parts. Physiology is the study of how the body works—it describes the function of the body and its organs, tissues and cells.

When fitness and healthcare professionals describe the location of anatomical parts, they refer to the anatomical position and the anatomical sections with the corresponding anatomical planes. There are also specific location terms used to describe the relative locations of body parts.

You learned about fibrous, cartilaginous and synovial joints. And you know that the type of connective tissue and amount of movement allowed classifies joints.

Movements also are classified based on type of movement and location. Some movements take place only in one plane, such as rotation, which moves along the transverse plane. Others, such as circumduction, may take place along two or more planes.

You are already on your way to becoming a knowledgeable and successful fitness professional! You can begin to talk the talk—fitness talk, that is. Take a few moments to complete your Quiz. In the next lesson, you’ll add to your anatomy knowledge base as we discuss the muscular and skeletal systems.


0203401LB02B-08-74


8-23

Just for FunWhew! That was a very technical lesson. You need to relax. Relaxation does not come easily for many—we are often terrible at it. We may not realize that we are stressed mentally or physically until a problem develops.

When your body is relaxed, your mind works more efficiently. There are some very simple physical relaxation exercises you can do as you work.

● If you spend time on the computer researching fitness information or developing exercise and nutritional plans for clients, give your eyes a rest from time to time. Try the 20, 20, 20 method. Every 20 minutes, take your gaze from the computer monitor and let your eyes rest on an object at least 20 feet away. Look at that object for 20 seconds.

● As a personal fitness trainer and nutritional specialist, it’s true that you’ll often be up and moving as you help your clients work out. But you will also spend time on the computer or sit for extended periods as you interview and talk with clients. In such cases, be sure to get up and move from time to time. Every hour or so, slowly stretch your arms above your head. Then, let your head and hands hang toward the ground. Keep that blood circulating!

● As you train with clients, work on the computer and develop nutritional and exercise plans, watch your posture. Are you slumping? It’s harder for your body to breathe when it’s in a poor position. Sit up and stand up straight and take in a few long, slow breaths.

● If you’re feeling stressed, try tensing and relaxing different areas of your body. For example, tighten your buttocks, hold it for a few seconds and then relax. Rotate your shoulders and head. Stretch your legs. Rotate your feet at the ankles.

The next time you’re feeling stressed, tired or overworked, give one or two of these relaxation tips a try! You might be surprised as to how helpful these simple techniques can be.

0203401LB02B-08-74


8-24

Lesson 9Musculoskeletal Anatomy and Physiology


● Identify the major parts of the skeletal system.

● Describe the muscular system.

● Explain how the muscular and skeletal systems work together.

● Determine why personal fitness trainers and nutritional specialists must understand musculoskeletal anatomy and physiology.

● Discuss muscle adaptations to strength training.

Step 2: Lesson PreviewValerie is a retired schoolteacher in her mid-60s. She belongs to several card and sewing clubs in the community. While she has enjoyed her retirement thus far, she dislikes that it has become increasingly difficult for her to get around physically. She is alarmed that she has gone from being extremely limber and physically fit to finding it difficult to do simple tasks around the house and keep up with her three young grandchildren.

Concerned that she has an illness that might explain her body’s rapid deterioration during the past few years, she seeks her doctor’s advice. After carefully reviewing her case history, Valerie’s physician suggests a surprising treatment plan: make an appointment with a personal fitness trainer and nutritional specialist at the local community health center.

The next week, Valerie, who has never participated in a formal exercise program, reluctantly attends her first session with a personal fitness trainer named Jaclyn. Jaclyn explains to Valerie how her physically active job as a teacher kept her bones and muscles strong. But the reduction in Valerie’s physical activity level after retirement allowed her musculoskeletal system to rapidly deteriorate.

While no disease is responsible for her current mobility problems, Jaclyn explains to Valerie that her physical inactivity puts her at greater risk for developing diseases including osteoporosis and heart disease. Jaclyn proposes a fitness plan for Valerie that includes weight lifting and aerobic activity several times a week. This will help her regain her muscle mass. Jaclyn asks that Valerie, who is extremely skeptical and frankly a bit intimidated by Jaclyn’s suggestions, try out her new fitness plan for one month.

0203401LB02B-09-74


9-2

Mobility problems like Valerie’s are extremely common, especially in older Americans or those who don’t get regular physical activity. For the most part, these difficulties can be traced back to a single rule regarding the musculoskeletal system. If you don’t use it, you lose it.

In this lesson, you will learn about the bones and muscles of the body. You will see how these body parts work together to make so much of what we do possible. This lesson will also explain why it is important that the personal fitness trainer and nutritional specialist understand this information. And at the lesson’s conclusion, we’ll check Valerie’s progress and see if she decides to make Jaclyn’s plan a permanent part of her lifestyle.

Though we’ll review some of the material covered in Lesson 8, this lesson introduces quite a bit of new material, and you may find it to be a bit more challenging than some of your other lessons. Don’t feel discouraged if you must take in this information a little at a time, and never hesitate to refer back to the reading during the Practice Exercises and Mail-in Quiz. And remember your instructor always is available to address any questions or concerns that may come up during your journey to a new career. We want you to succeed at mastering this material. We want you to become the best personal fitness trainer and nutritional specialist you can be!

Now, let’s begin this lesson by talking about the skeletal system.

Step 3: The Skeletal SystemThe skeletal system is the backbone of the body. In fact, the spine or backbone is a stack of bones and joints that makes it possible for us to stand upright. All the other bones of the skeleton have the same basic function: to support the soft tissues of the body. Even so, the skeletal system is more than a support system.

In a previous lesson, you learned that bones are actually living tissue, just like the skin, brain and heart. The skeletal system is responsible for a number of activities throughout life. Bones are responsible for making red and white blood cells, storing fat and regulating the body’s supply of phosphorus and calcium. Normal calcium levels are necessary for muscle contraction, nerve impulse conduction and blood clotting. As you can see, bones are in a constant state of activity, working alone and with other tissues and organs to ensure the body functions properly.

Bone TissueMuch like the skin, bone tissue is made up of layers, like an onion. The solid, outermost layer of bone tissue is compact bone. It is made up of cells called osteocytes. The innermost, center part of bone tissue is hollow and is called the marrow cavity. The tissue that lies between the outer compact bone and the inner marrow is called cancellous bone.

Growth CentersWhile still in the womb, a fetus develops a cartilage framework from which his bones will be formed. The process in which bone gradually replaces this cartilage is called endochondral bone formation. Endochondral bone formation occurs in the growth centers of long bones, such as those that make up the fingers, arms and legs. As these growth centers erode the cartilage and replace it with bone, the bone gets longer or larger. When the bone end closes, typically shortly after puberty, bone lengthening and enlargement stops.

0203401LB02B-09-74

Musculoskeletal Anatomy and Physiology

9-3

After bone closure, even though the bones are no longer getting larger or longer, they do continue to make new bone and absorb old bone, sort of like marching in place so that the bone appears stable in size and shape. This turnover of bone becomes obvious when a bone is broken. Injured bone grows new bone faster than old bone is absorbed or broken down; therefore, the broken bone heals.

As long as a person is alive, her bones are in a constant state of turnover. As a personal fitness trainer and nutritional specialist, explain to your clients that weight-bearing activity encourages the body to form new bone. This increases bone strength and density and protects them from osteoporosis. Likewise, a diet that provides adequate amounts of protein, vitamins and minerals helps ensure that the bones stay strong and healthy.

Parts of the Skeletal SystemThe skeletal system isn’t just a pile of bones; it contains other connective tissues, as well. In Lesson 8 we talked about joints and connective tissues, but now let’s talk about some of these items in a bit more detail.

JointsYou’ll recall from Lesson 8 that joints are areas where bones come into close contact with one another. You already learned that the three basic joint types are:

● Fibrous

● Cartilaginous

● Synovial

The first type of joint, fibrous, has little or no range of motion unless put under abnormal stress. You learned in Lesson 8 that most of the joints in the head and trunk are fibrous joints, as are the sutures between the bones of the skull. The edges of two flat bones with a small amount of fibrous tissue in between form the fibrous joints of the skull. It is because these joints don’t fuse until several months after birth that a baby has soft spots on its head. Once these joints close, any motion of them would be alarming, to say the least!

Remember that cartilaginous joints allow a limited range of motion. The joint that connects the two long bones of the forearm is an example of a cartilaginous joint. This joint allows the two attached long bones to rotate around each other somewhat so that you can do things like unscrew a jar or rotate your forearm.

Other examples of cartilaginous joints are the intervertebral disk spaces between the vertebrae of the spine and the joint that connects the two sides of the pubic bone. These cartilaginous joint spaces are filled with a solid, rubbery material. The cartilaginous joint that connects the two sides of the pubic bone softens and loosens in a pregnant woman just before delivery, allowing more motion. Unfortunately, this loosening also makes walking late in pregnancy more difficult, since the joint is now unstable.

Synovial joints are the joints you probably know best because they are the ones that move freely. Remember, all of the joints in the extremities or limbs are synovial joints. Synovial joints have a number of things in common:

● These joints are enclosed in a capsule lined with a synovial membrane, which secretes synovial fluid for lubrication.

● The end surfaces of the bones are covered with a layer of cartilage.

0203401LB02B-09-74


9-4

● The joints have a joint cavity that is a flat space that can balloon up when it is filled with too much fluid.

● The ends of the bones are held in place by the ligaments that make up the joint.

Synovial joints are further classified by the type of motion they allow. Some joints, like the wrist, allow slipping motions, like marbles rolling over each other in a bag. Others bend around an axis, like the knee or the fingers. Recall the table that explained the six types of synovial joints and the motion they allow in Lesson 8.

CartilageAnother important part of the skeletal system is cartilage, which we discussed in Lesson 8. Cartilage is a specialized type of connective tissue on which bone is built. Like bone, it is hard and provides support for other kinds of soft tissue. Cartilage is white and shiny in appearance and is composed of cells called chondrocytes. In Lesson 8, you learned about the three types of cartilage:

● Hyaline cartilage

● Fibrocartilage

● Elastic cartilage

The first and densest of the three types of cartilage is hyaline cartilage. A tough membrane covers this type of cartilage. Hyaline cartilage connects the ribs to the sternum or breastbone. It also makes up the nasal septum or wall inside the nose.

The second type of cartilage, fibrocartilage, is not as dense as hyaline cartilage, and it is much more flexible. Fibrocartilage forms the joints between bones that need a lot of cushioning, like the disks that lie between each of the vertebral bones in the spine.

A final type of cartilage, elastic cartilage, is, as the name suggests, the most flexible cartilage of all. Elastic cartilage contains many elastic fibers that form a mesh-like network. Remember, you learned that your ear and the outer ear canal both contain elastic cartilage.

LigamentsIn Lesson 8, you read that ligaments are tough, fibrous connections between two bones, while tendons are tough, fibrous connections between a muscle and a bone. Ligaments are another important component of the skeletal system. Unlike bones that easily are seen on plain radiographs, ligaments aren’t visible in these pictures. Ligaments are strong bands of dense, regularly arranged connective tissue that connect one bone to another at joints. Like hinges on a door, they allow the joints to move enough for flexibility but determine a specific ROM so that the joint is useful. Some joints, like the ones between the ribs and the sternum or breastbone, are made up of ligaments that allow almost no motion, while others, like those found in the ankle, have a very wide ROM. Do you recall from Lesson 8 that ROM stands for range of motion?

0203401LB02B-09-74


9-5

Skeletal PhysiologyNow, let’s talk about some of the features of skeletal physiology. Remember, physiology is the study of a living organism and its parts. In this case, we’re studying the human body and its bones! In Lesson 4, you learned that the body likes to maintain homeostasis, or a state of balance. Bone helps to maintain a balance between the amount of calcium found in the blood and the amount of calcium found in the bones. Bone interacts with the thyroid gland and the parathyroid gland to provide calcium and phosphorus homeostasis. Two hormones, calcitonin and the parathyroid hormone or PTH, handle this interaction.

Another important factor in the homeostasis of calcium and phosphorus is the presence of Vitamin D. Vitamin D is necessary for the intestine to absorb calcium and phosphorus from the food we eat. You may remember from the vitamin and mineral chart in Lesson 5 that calcium and phosphorus work together to build bones and teeth. Without Vitamin D, the homeostasis of the parathyroid, thyroid and bone is disrupted.

Stress also is a factor in skeletal activity. But we’re not talking about the kind of stress you feel when you’re overworked or upset. This is the kind you feel when you lift a heavy box. It is stress that tells bone where to lay down new bone. Earlier in this lesson, you learned that the bones are constantly tearing down bone tissue and building up new bone tissue in a homeostatic way. That is why bones don’t appear to change their size and shape in healthy adults.

Excess stress on a bone causes one of the most dramatic examples of change in bone physiology. This is a fracture. A fracture is a break in the bone. Within a few days or weeks of a fracture, a cloud of bone and collagen forms around the fracture site. This cloud is called a callus formation. Like a plaster cast inside the body, the callus acts to naturally splint the fracture, preventing motion at the fracture site. If a callus does not form and the two broken bone ends continue to move, a false joint is created.

Bones of the Axial and Appendicular SkeletonNow that you have an understanding of some of the features of the bones, let’s talk about the bones of the axial skeleton and appendicular skeleton. The bones of the axial skeleton are those in the long axis of the body. They include:

● The skull and facial bones

● The spine

● The bony thorax

0203401LB02B-09-74


9-6

Figure 9-1: Axial and Appendicular Skeleton

The skull is the part of the skeleton that encases the brain and the special sense organs, as well as forms the face. The facial bones come in pairs, except for the mandible or jaw and the nasal septum. The six pairs of facial bones are the nasal, maxilla, palatine, lacrimal, zygoma and inferior nasal concha. The spine is called the vertebral column because it is a column of 33 vertebral bones that support the body. The primary function of the vertebral column is to protect the spinal cord. Also, since humans stand upright, the spine must support the weight of the upper body. Lastly, the bony thorax includes the thoracic spine, ribs and sternum. The bony thorax protects the heart and allows room for inflation and deflation of the lungs. Since it looks like a birdcage, the bony thorax is often known as the ribcage.

The remaining bones in the extremities or limbs and the pelvis are called the appendicular skeleton because they are appendages of the axial skeleton. These bones include:

● Shoulder girdles

● Pelvic girdle

● The extremities

The shoulder girdle attaches the upper arm to the axial skeleton. It is made up of two bones, the clavicle or collarbone and the scapula or shoulder blade. The upper extremity includes the arm, forearm, wrist and hand. The pelvic girdle is a ring of bones connecting the bones of the legs to the axial skeleton. The bones of the lower extremity include the thigh, leg, foot and ankle.

In your muscular focus lessons, you’ll learn more about these bones. Next, we’ll take a look at the muscular system. But first, use the following Practice Exercise to review what youve learned so far.

0203401LB02B-09-74


9-7

Step 4: Practice Exercise 9-1Select the best answer from the choices provided, and write your answers on scratch paper.

1. The _____ system is the backbone of the body.a. muscular b. skeletalc. respiratoryd. cardiovascular

2. The solid, outermost layer of bone tissue is called _____.a. compact boneb. spongy bonec. bone marrowd. cancellous bone

3. Which of the following is NOT an example of a cartilaginous joint? a. The joint that connects the two long bones of the forearmb. The intervertebral disk spaces between the vertebrae of the spinec. The joints in the head and the trunkd. The joint that connects the two sides of the pubic bone

4. The cells that compose cartilage are called _____.a. chondrocytesb. osteocytesc. lamellad. callus

5. Bone interacts with the thyroid gland and the parathyroid gland to provide _____ homeostasis. a. calcium and phosphorusb. thyroid and parathyroid c. calcitonin and PTHd. bone and muscular

6. The cloud of bone and collagen that forms around the site of a fracture is called a _____.a. pseudarthrosisb. appendicularc. callus formationd. chondrocyte

0203401LB02B-09-74


9-8

7. The _____ is the part of the skeleton that encases the brain and the special sense organs, as well as forms the face. a. facial boneb. spinec. bony thoraxd. skull

8. The bones in the extremities or limbs and the pelvis are called the _____ skeleton because they are appendages of the axial skeleton. a. axialb. appendicularc. canellousd. auxiliary

Step 5: Review Practice Exercise 9-1Check your answers with the Answer Key at the back of this book. Correct any misakes you have made.

Step 6: The Muscular SystemThe muscular system consists of organs that produce movement anywhere in the body by contracting and relaxing. You learned in Lesson 4 that muscles account for about 40 percent of body weight.

Muscles are found not only in the extremities, like the biceps muscle that bulges when you flex your arm, but also in almost every organ system in the body, except the neurological system.

Muscle PhysiologyThere are two kinds of muscle function:

● Voluntary

● Involuntary

Generally, voluntary muscle function occurs when you intentionally contract a muscle—for example, when you bend your leg, make a fist or consciously move any part of your body. Other muscle functions, such as the beating of your heart, the contraction of your bowel and breathing, are involuntary, since they occur whether you are conscious or not.

You already learned in this course that some involuntary muscle functions can come under voluntary control and vice versa. For example, when you feel pain, you involuntarily jerk back from the source of pain. On the other hand, you can voluntarily control your breathing and the blinking of your eyes.

0203401LB02B-09-74


9-9

The skeletal muscles usually carry out voluntary muscle function. Skeletal muscles are those connected to the skeleton or other connective tissue. Skeletal muscles perform three general functions:

● Maintaining an upright posture

● Making motion that is easily observed

● Generating heat

Muscles located in the internal organs of the body usually carry out involuntary muscle functions. Smooth muscle and cardiac muscle are both examples of involuntary muscles. These muscles perform functions such as:

● Pushing the contents of tubes, ducts and vessels along their passageways. For example, muscles propel food through the digestive tract, blood through the arteries and urine through the ureters.

● Evacuating contents stored in sacs and cavities in the body—for example, squeezing bile from the gallbladder and tears from the lacrimal sacs.

● Regulating the width of tubes—for example, increasing or decreasing the diameter of blood vessels to increase or decrease blood pressure. Another example is increasing or decreasing the diameter of the bronchioles in the lung.

Muscle Cell PropertiesMuscle cells have a number of properties that give them their ability to create motion. These properties include contractility, extensibility, elasticity and irritability. Let’s take a closer look at each of these properties and what they allow the muscles to do.

ContractilityThe first property of muscle cells is contractility. Contractility means muscle cells have the ability to shorten or try to shorten. This creates tension between the two end points where the muscle fibers are attached. Isotonic contraction is the shortening of muscles. This usually produces motion, such as flexing your arm, opening your mouth, lifting items or moving any part of the body. On the other hand, isometric contraction occurs when a muscle tries to shorten, but shortening is prevented. This produces heat and tension rather than motion. Isometric contraction occurs, for example, when you push against a wall. You can’t move the wall, but you create a lot of tension between your hands and the wall. Isokinetic contraction occurs when the muscle contracts and shortens at a constant speed.

ExtensibilityMuscles also have extensibility, meaning they can stretch when they are pulled. For example, the contraction of the biceps muscle flexes your elbow and contraction of the triceps muscle straightens your elbow. Muscles that contract at a joint are paired with muscles that relax at a joint; these opposing muscle pairs are what permit motion around the joint. When you bend your elbow and flex the biceps muscle in your arm, the triceps muscle has to relax to allow the elbow to bend.

0203401LB02B-09-74


9-10

Extensibility also allows the urinary bladder, stomach and uterus to stretch as they become filled. When a muscle stays stretched, it can adjust to the new length. If the stretching occurs slowly over a long period of time, as the uterus does in pregnancy, the amount of stretching is amazing. Likewise, we can train our voluntary muscles to stretch beyond their normal limits through yoga, gymnastics or a variety of other practices in the gym.

ElasticityA third property of muscles is their elasticity. It is the elasticity of muscles that allows them to snap back to their original size and shape after stretching. Sometimes this occurs very quickly, like when you stop flexing your arm muscles, or very slowly, like a uterus returning to its normal size after pregnancy, which can take many weeks.

IrritabilityThe final and most unique property of muscle cells is irritability. Irritability is the ability of the muscle to respond to a stimulus. A stimulus is something that causes a response. Compare it to a light switch. Just as hitting a light switch turns on a light, hitting a stimulus turns on a muscle. Muscles respond to a number of different stimuli, such as nerve impulses, hormones, touch and heat. A neuron or nerve cell usually stimulates a muscle cell. In the voluntary muscles, this nerve cell is called a motor neuron.

Motor UnitTo see how muscles work, let’s look at a motor unit, which is one motor neuron and all the voluntary muscle cells that neuron stimulates. The neuron has long, thread-like projections called nerve fibers or axons. The axons have branches where they reach a muscle cell. These branches are called motor end plates. These end plates form a neuromuscular junction with the surface of a muscle cell. The motor end plates and the muscle cell surface don’t actually touch. The gap between the motor end plates of a nerve cell and a muscle cell is called a synapse.

When the nerve impulse reaches the motor end plates, a chemical called a neurotransmitter is released; it travels across the synapse to the muscle cell. The neurotransmitter helps create an electrical current that causes calcium to be released inside the muscle cell. Calcium allows two proteins in the muscle filament to pull toward each other, causing a sliding action that contracts the muscles. In Lesson 4, you learned that the energy that drives the muscles to contract comes mostly from ATP. Each nerve impulse causes a muscle cell contraction that lasts just 0.005 seconds. Therefore, continued contraction of the muscle cell requires many nerve impulses.

Figure 9-2: Components of the Motor Unit

0203401LB02B-09-74


9-11

For a stimulus to cause contraction of a muscle cell, two conditions apply:First, the intensity of the stimulus must lie within a certain range. It must be strong enough to cause an electrical current to begin.

Second, the all-or-none principle means that when a muscle fiber contracts, it contracts completely or not at all.

Muscle ContractionThe process we just described applies to a single motor unit. Now, let’s look at the response of a whole muscle, which is composed of many muscle cells.

As we looked at the motor unit, we discussed how individual muscle cells react. However, in large voluntary muscles, the muscle is made up of a large number of motor units, so they appear to follow different rules. Although a single muscle cell will contract completely—never partially—when it is stimulated, a large voluntary muscle, like the biceps, can partially contract because only some of the muscle cells are stimulated.

Because you can selectively stimulate part or all of the muscle cells in the biceps muscle, you can flex your biceps muscle slowly—it is not an all-or-none response. There are two ways to vary muscle contraction. One is by increasing the rate of muscle stimulation, and the other is by increasing the number of muscle cells stimulated.

When the rate of muscle stimulation is low, you can see individual twitches in the muscle, one for each nerve stimulus to the muscle. As the rate of stimulation increases, the muscle cells already stimulated haven’t had time to relax before new muscle cells are stimulated, causing a more rhythmic, stronger and smoother type of contraction. As the rate increases even further, there is no time for any muscle cell to relax; the muscle contraction is smooth and lasts a long time.

The strength of a large muscle contraction depends on how many muscle cells in the muscle are stimulated. If only a few muscle cells are stimulated, the contraction will be much less forceful. In more forceful motions, more muscle cells are stimulated at once. For example, lifting a feather requires the stimulation of fewer muscle cells than lifting the whole chicken.

If all of your muscles were in complete relaxation, you wouldn’t be able to stand up or even sit up. You are able to do these things with little or no effort because different groups of fibers within a muscle alternately relax and contract in such a subtle way that it isn’t noticeable. This continuing contraction of small groups of muscle fibers in every muscle is called muscle tone.

Muscles that lose their tone become soft and limp and appear flabby. A person who has lost a great deal of muscle tone will find it increasingly difficult to do simple tasks, such as sitting or standing up. Likewise, muscles that are not regularly exercised, like your abdominal muscles, lose their ability to hold in your tummy. Think back to Valerie, whom you met at the beginning of this lesson. She was having a hard time physically getting around because her muscles weren’t getting regular exercise. She had lost muscle tone.

0203401LB02B-09-74


9-12

Oxygen DebtIn Lesson 7, you learned that your muscles have the energy to contract because ATP is present in your system. Most muscles contain an adequate supply of ATP for quite a number of contractions before the ATP runs out. You can keep going comfortably as long as your body can keep up. Eventually, if you exercise long enough or intensely enough, your muscles get tired.

When you exert your muscles for a high-intensity activity, such as lifting a weight for a very short time, your muscle is tired because the cells run out of ATP. The fibers of the muscle have no energy and can’t contract. When you exercise heavily for a longer period of time, the muscles get tired because lactic acid accumulates in them.

The amount of oxygen it takes to break down the lactic acid is called the oxygen debt. In a way, the muscles have been borrowing ATP on credit, using an anaerobic process (such as glycolysis, which you learned about in Lesson 7), instead of aerobic production of ATP from oxygen in the bloodstream. And, like any debt, the oxygen debt must be repaid before the muscles can once again function properly.

Oxygen debt occurs very commonly in strenuous activity. When the body is in oxygen debt, respirations become labored, which is why you breathe heavily after strenuous exertion. You are paying back the oxygen debt to your muscles!

EnduranceWe talked about endurance in your previous lessons. Endurance is what lets you exercise for longer periods of time before your muscles become tired. Increasing the amount of oxygen available to our muscles increases our muscular endurance. So, how do we increase the amount of oxygen available to our muscles? The answer lies in aerobic exercise that builds endurance by both increasing the blood supply to the muscle and increasing the mitochondria in the muscle cells. Remember, it is the mitochondria that store oxygen and create ATP. The more oxygen that is stored in the muscle tissue, the longer it will take to develop oxygen debt.

ResistanceJust as aerobic exercise increases muscular endurance, resistance exercise increases the size, strength and tone of muscles. One example of resistance exercise commonly used during fitness training is repetitive weight lifting.

The differences between aerobic exercise and resistance exercise are easy to remember. Aerobic exercise helps raise muscular endurance by increasing oxygen availability. This is the kind of change the muscles of a marathon runner need. Resistance exercise increases the size and strength of muscles. Resistance exercise creates the kind of change needed in the muscles of body builders. Comparing a marathon runner’s body with that of a body builder’s body shows that when it comes to our muscles, there is a remarkable range of physiological possibilities!

0203401LB02B-09-74


9-13

Location, Location, LocationIn Lesson 4, you learned that our bodies contain more than 640 skeletal muscles. We won’t discuss every muscle in the human body, but we will identify and describe the purposes of the major skeletal muscles.

Just like the bones of the skeleton, muscles are divided into axial muscles and appendicular muscles. The axial muscles are those of the head, face, neck and trunk. The appendicular muscles are those that lie in the extremities. Let’s start with the axial muscles.

The muscles of the head and face have a number of very important functions. First, they move the facial features. This allows facial expression for emotions from joy to grief. These muscles also allow us to squint our eyes, suck on a straw or whistle. In addition, the muscles allow us to talk, chew and swallow our food. The neck muscles allow the head to perform a number of motions, such as bowing the head, tilting the head backward and bending the head and neck to touch the shoulder.

The trunk muscles help protect many of our delicate internal organs. They also allow the spine to flex, extend and bend. In addition, these muscles—along with the ribs—form the wall of the thoracic cavity, the wall of the abdominal cavity and the muscular wall of the pelvic cavity. There are many paired muscles lining the bony pelvis that form the muscular wall of the pelvis. These muscles generally support the pelvic and abdominal organs, and some act as sphincter muscles, causing the rectum, urethra and vaginal walls to expel their contents.

The upper and lower extremity muscles are appendicular muscles. Some of the upper extremity muscles lie in the trunk or back, but are responsible for moving the arm. The muscles of the lower extremity may also lie in the trunk, but are responsible for moving the leg. The muscles of the lower extremity are generally more massive than the muscles of the upper extremity since they bear more weight and help maintain an erect posture.

Later in this course, we will talk in detail about the actions of many of the body’s muscles. Understanding these muscle actions will allow you to best educate your clients regarding effective exercise practices. Now, before we move on to discuss how the muscular and skeletal systems work together, complete the following Practice Exercise.

Step 7: Practice Exercise 9-2For the following questions, choose the best answer from the choices provided.

1. Which type of muscle function are you engaging when you bend your leg, make a fist or consciously move any part of your body? _____a. Voluntaryb. Involuntaryc. Cardiacd. Smooth

0203401LB02B-09-74


9-14

2. _____ muscle tissue usually carries out voluntary muscle function?a. Cardiacb. Smoothc. Skeletald. Resistant

3. Muscles located in the _____ usually carry out involuntary muscle functions.a. fingersb. internal organs c. armsd. jaw or mandible

4. The ability of muscle cells to shorten or try to shorten is _____.a. contractilityb. extensibilityc. elasticity d. irritability

5. The ability of the muscle to respond to a stimulus is _____.a. contractilityb. extensibilityc. elasticity d. irritability

6. The gap between the motor end plates of a nerve cell and a muscle cell is called a(n) _____.a. axonb. synapsec. actind. neurotransmitter

7. The continuing contraction of small groups of muscle fibers in every muscle is called _____.a. muscle toneb. muscle endurancec. muscle resistanced. involuntary

8. The _____ muscles help protect many of our delicate internal organs. a. neckb. facec. headd. trunk

0203401LB02B-09-74


9-15


Step 9: How Do the Skeletal and Muscular Systems Work Together?

Now that we have explored the muscular and skeletal systems individually, let’s take a look at the variety of ways these two systems work together to allow us to carry out a wide range of movements. We’ll also examine the role that our connective tissues play in the work of the musculoskeletal system.

Movement and the Musculoskeletal SystemWithout the help of bone, muscle tissue would be unable to exert any kind of pushing or pulling force. This is because muscle tissue exerts force indirectly by pulling against bones that then exert force on the environment. Muscles are only capable of pulling motions. So, how is it that we can do pushups or push a door open? Well, the muscles and bones work together! Muscles need a system of bones and joints to enable their pulling forces to exert pushing forces. Bones give muscles the leverage they need to perform the many actions of which our bodies are capable.

To generate force on an external object, a muscle must be attached to a bone at both ends. Connective tissues, or tendons, attach muscles to the bones on which they exert force. Therefore, when it comes to optimal strength and fitness performance, the importance of healthy tendons cannot be underestimated. Regular physical activity increases both the quantity and quality of tendons between bones and muscles. When a person has weak or injured tendons, his strength and performance abilities decrease.

Nearly all body movement requires the use of more than one muscle. We refer to the muscle that most directly generates the force for a particular movement as the prime mover or agonist. The muscle most involved in slowing or stopping a movement is the antagonist. The antagonist stabilizes the joint while bringing motion to a halt to prevent harm to ligaments and cartilage.

To understand the importance of muscle antagonists, consider what happens when you throw a baseball. The agonist muscle—in this case, the triceps muscle—extends the elbow to propel the ball forward. Once the elbow nears full extension, the antagonist—biceps muscle—is responsible for bringing this extension to a halt. Without the antagonist muscle, overextension, and therefore unnecessary wear and tear of the elbow joint, would occur every time you threw a ball! As you can see, agonists and antagonists work together to let us perform movements with as little strain on our joints as possible.

A muscle that plays an indirect role in movement is known as a synergist. For example, the muscles that provide stability to the shoulder, allowing a variety of arm movements, act as synergists. Agonist, antagonist and synergist muscles all play unique but important roles in bodily movement. By understanding how these muscles work together, personal fitness trainers and nutritional specialists are able to design safe yet effective training programs.

0203401LB02B-09-74


9-16

Strength Factors and the Musculoskeletal SystemThe shape and arrangement of the muscles and bones play a role in a person’s overall strength abilities. While the quality of muscle tissue is equal in men and women, men generally have a higher quantity of muscle tissue than women. This difference is partially because of higher testosterone levels in men.

A second factor that determines an individual’s muscle strength is age. People of all ages, including the elderly, can make strength gains, but the most rapid gains generally occur during the growth years, which are ages 10 to 20. Just as muscles are most apt to develop during the first few decades of life, bones gain most of their density during this time, too. You’ve learned in your previous lessons that an individual who does not perform regular strength training loses lean muscle mass. Since this loss of lean muscle mass lowers a person’s metabolic rate, many people begin to put on weight as they age, even if their dietary intake remains the same. Strength training increases lean muscle mass and bone density, and this counteracts the natural effects of aging.

A third factor that can affect a person’s lifting strength is muscle length. You learned earlier in this lesson that connective tissues called tendons are what attach muscles to bones. Some individuals have long muscles and short tendons, while others have shorter muscles and longer tendons. Muscle and tendon length are probably determined genetically, and people with longer muscles have the ability to develop slightly larger and stronger muscles than those with shorter muscles.

A final factor that determines someone’s muscle strength is limb length. A person with shorter limbs has a leverage advantage, allowing him to lift more weight at 90 degrees than a person with identical strength but longer limbs. This is why many competitive weight lifters are relatively short and stocky.

All of the subtle factors we’ve discussed here come together to determine a person’s lifting abilities and muscle development potential. Therefore, as a personal fitness trainer and nutritional specialist, it is important that you avoid comparing one client’s progress or abilities with another’s.

Step 10: Real-world ApplicationsUnderstanding the musculoskeletal system is necessary for personal fitness trainers to design effective training programs for their clients. Safety and the avoidance of injury are also important when developing training programs, and we’ll discuss the injury risks in a later lesson.

Different training goals require different numbers of repetitions while lifting weights, as well as different loads of weights. Understanding how muscles adapt to strength training and the roles that fast- and slow-twitch muscle fibers play are important considerations in designing a program. Let’s take a look at how the information in this lesson is applicable to the everyday work of a personal fitness trainer and nutritional specialist.

Muscle Fiber TypesOur muscles are composed of two main fiber types. The first type of muscle fibers, slow-twitch fibers (Type I), are used heavily during aerobic activity—activities that use oxygen and can be sustained for a fairly long period of time. Slow-twitch muscle fibers have a large number of mitochondria. Remember, it is those mitochondria that let them generate ATP so efficiently. This, in turn, lets slow-twitch muscle fibers fuel the repeated muscle contractions necessary for aerobic activities. Examples of aerobic activity include biking, swimming laps and jogging.

0203401LB02B-09-74


9-17

The second main type of muscle fiber is called fast-twitch fibers. Fast-twitch fibers (Type II) are better suited for anaerobic exercises that require short bursts of intense activity. This is because they don’t contain the amount of mitochondria that slow-twitch fibers do, so they aren’t as efficient when it comes to generating ATP. Remember, anaerobic activities are performed with insufficient oxygen; examples include power-lifting and short sprints.

Fast-twitch fibers can be categorized further into Type 11a and Type 11b fibers. Type 11a are intermediate, fast-twitch fibers that can use anaerobic and aerobic metabolism to create energy. Type 11b fibers use anaerobic metabolism to create energy, and are the classic fast-twitch fibers.

Strength training exercises typically use both fast- and slow-twitch muscles. Slow-twitch muscles are used first. Though these fibers fire less often than do fast-twitch fibers, they are more resistant to tiring than their fast-twitch counterparts. As the muscles begin to tire, fast-twitch muscles kick in and are used until the point of exhaustion. Fast-twitch muscle fibers fire more rapidly than do slow-twitch muscle fibers. And they generally show bigger increases in muscle size and strength through strength training than slow-twitch muscle fibers.

Training Load and RepetitionsThe amount of weight used during resistance training is the load, while the number of times the exercise is performed is known as repetitions. As the load increases, the number of repetitions that can be done decreases, and as the load decreases, the number of repetitions that can be done increases.

The load and number of repetitions performed depend on the specific exercise goal or desired muscular changes. The three most common goals for muscular change are increased muscle strength, increased muscle size and increased muscular endurance. Each of these resistance-training goals requires a different load, repetition and rest schedule.

Training to Increase Muscle Size and StrengthWhen a client’s main goal is to increase muscular size and strength, the personal fitness trainer can help him accomplish this goal by having the client train with heavy loads. These loads should be about 70 percent of a person’s maximum lifting ability for a single lift. Eight to 12 repetitions are recommended, as is a full recovery or rest period—about three minutes—between sets. Sets refers to the number of times a person repeats a number of repetitions. For example, a client might do three sets of 10 repetitions—lift a weight 10 times, three different times, for a total of 30 repetitions. The training volume is the total number of repetitions performed across all sets during a workout.

This training pattern helps develop fast-twitch muscle fibers more quickly than slow-twitch muscle fibers, because fast-twitch fibers are used most heavily while lifting heavy loads. Furthermore, fast-twitch muscle fiber growth is largely responsible for increases in lean body mass, a key determinant of muscular strength.

Training for Muscular EnduranceThose involved in endurance sports may train to increase their muscles’ capacity to work longer. Increasing muscular endurance requires a training schedule that uses a low workload, a high volume of repetitions and minimal recovery times. For example, a client might lift a small amount of weight for as many as 20 repetitions, resting for only about one minute between sets. Many types of aerobic activity follow this type of schedule and thus help increase muscular endurance.

0203401LB02B-09-74


9-18

Slow-twitch muscle fibers are heavily used during extended periods of low-load training and are more likely to be further developed during this type of training than fast-twitch muscles. The development of slow-twitch fibers does not result in the muscle size and strength gains seen in fast-twitch fiber development. This helps explain the differences between a marathon runner’s and a bodybuilder’s physique.

Aerobic endurance exercise also results in increases in mitochondria within muscle cells. Myoglobin, a protein that transports oxygen to cells, also increases in volume as a result of endurance training. These increases in both mitochondria and myoglobin further enhance muscular endurance.

Basic Resistance Training GuidelinesThere are some general rules or guidelines that can apply to most any training program, regardless of the specific objective. These guidelines help ensure efficient muscle development and a decreased risk of injury.

Exercise SelectionThe first rule calls for at least one exercise for each major muscle group. Some clients may be tempted to work out only select muscle groups while neglecting others. A common example would be working the biceps and deltoids in the arms, while failing to strengthen the core and stabilizing muscles located in the back and shoulders. Muscle strains and pulls commonly result as the neglected back and shoulder muscles are unable to keep up with the demands placed on them from increased biceps and deltoid lifting loads.

Exercise SequenceAnother general rule to follow during resistance training involves exercise sequence. Lifting with the large muscles of the legs tends to demand more energy than lifting with the smaller muscles of the arms, torso and neck. For this reason, it is wise to start with the most demanding exercises when the body is least fatigued, then move on to the less demanding exercises. A second option is to switch between upper- and lower-body exercises to enable adequate rest periods between sets.

Exercise SpeedA final resistance training guideline involves exercise speed. How fast an individual performs each repetition impacts both his muscle development, as well as his injury risk. Lifting a load at a fast pace puts extra stress on the joints and requires less overall control of the load. Since control is an important objective of resistance training, a slower lifting pace is most beneficial. Lifting a load slowly requires the muscles to work evenly throughout the repetition, resulting in more expansive and balanced muscular development. Furthermore, lifting done in a slow and controlled manner causes less stress on the muscles and joints, and thus less wear and tear.

Strength PlateausWhen most people begin a strength-training program, they experience an initial period of strength gain, particularly during the first several weeks or months. After this time, however, many people find their strength capabilities remain stable for an extended period of time. This is known as a strength plateau. By understanding how the muscles adapt to strength training, personal fitness trainers can use several strategies to help their clients overcome these strength plateaus and continue to make fitness progress.

0203401LB02B-09-74


9-19

Training FrequencyYou know from Lesson 7 that frequency refers to the number of exercise sessions in a week. The increased demands that lifting heavier weights put on an exerciser’s muscles often call for longer recovery periods between workout sessions. After all, lifting heavier loads breaks down more tissue, and the more tissue that is broken down, the longer it takes for the body to repair itself. Therefore, reducing training frequency often yields better exercise performance and allows an individual to overcome a strength plateau. An extra day between workouts can make all the difference when it comes to tissue repair, and this results in strength gains.

Training ExercisesMuscles adapt to the specific movements done during resistance training. This is often the result of drawing on the same muscle fibers for each repetition, which can bring muscle strength progress to a stop. In this situation, finding ways to target other muscle fibers in a given muscle can be key to overcoming strength plateaus. A good example would be switching from the bench press to the incline press, chest cross or bar dip. We’ll talk more about these different types of exercises in this course, but for now, just remember that all of these exercises target the same muscles. However, they require the muscles to fire differently, helping engage different muscle fibers.

Resistance and RepetitionsAnother possible strategy for overcoming strength plateaus involves switching the amount of resistance and number of repetitions performed. For example, if eight repetitions of 60 pounds becomes a strength plateau, the client may benefit from doing 12 repetitions of 50 pounds. In the previous section, you learned how fewer repetitions with a near-maximum load helps develop fast-twitch muscle fibers, while more repetitions with less resistance utilizes mainly slow-twitch fibers. By switching the amount of resistance and the number of repetitions a client performs, you cause her to engage more muscle fibers. This, in turn, helps her overcome a strength plateau.

Breakdown and Assisted TrainingUsing more muscle fibers and overcoming strength plateaus can also be achieved through breakdown training. During breakdown training, an exercise is performed using a given load until the muscles are fatigued. Then, the load is reduced so that the muscles are able to perform two or three more repetitions of the exercise. By pushing the muscles to the point of fatigue twice, more muscle fibers are engaged and developed. Along the same line as breakdown training is assisted training, during which the client is able to perform two or three repetitions following fatigue with help in lifting the weight from his trainer.

Negative TrainingNegative training refers to lowering weight loads that are too heavy for a given individual to lift. This type of training focuses only on the slow lowering of the weight, which a person does without the help of a spotter. Then, the spotter helps the lifter bring the weight back up. Such training helps people gain muscle strength rapidly, but because the nature of negative training puts one at greater risk for injury, it is important that the personal fitness trainer assist the client performing these exercises.

0203401LB02B-09-74


9-20

Slow TrainingThe muscles must work harder if one slows down the speed at which he lifts and lowers a weight. Slowing down individual repetitions keeps momentum to a minimum and forces the muscles to put forth a greater effort. When performing slow training, aim for 10 seconds of lifting motion and four seconds of lowering motion. When done correctly, the muscles will fatigue in fewer repetitions than normal training.

Additional Types of Training ● Performing two exercises for the same muscle group back to back is called a compound set.

● When muscles are too tired to fully lift the weight, you can continue to lift the weight only as far as you can for a few more repetitions. This is called a partial.

● When opposing muscle groups are worked in succession without a break between sets, it is called a super set.

● After performing a full set, remove half the weight and immediately continue lifting the weight until you are exhausted. This is called a burn-out set.

Well, you’ve certainly learned a lot about the muscular and skeletal systems. You’re almost ready to take your final quiz. But first, let’s make sure you understand the material. Review what you’ve read with the Practice Exercise.


1. To generate a force on an external object, a muscle must be attached to _____.a. a bone at both endsb. a bone at one endc. another muscle at both endsd. another muscle at one end

2. The muscle that most directly generates the force for a particular movement is referred to as the _____.a. antagonistb. agonistc. tendond. synergist

0203401LB02B-09-74


9-21

3. The muscle most involved in slowing or stopping a movement is referred to as the _____.a. antagonistb. agonistc. tendond. synergist

4. On average, men have more muscle tissue than women as a result of men’s higher levels of which hormone? a. Estrogenb. Progesteronec. Testosteroned. Cholesterol

5. Which type of muscle fiber is used most heavily during aerobic activity? a. Slow-twitchb. Fast-twitchc. Renewabled. Repetitive

6. The amount of weight that is used during resistance training is the _____.a. volumeb. loadc. repetitiond. strength plateau

7. Lifting a load _____ puts extra stress on the joints and requires less overall control of the load. a. at a slow paceb. at a fast pacec. without the help of a personal fitness trainerd. frequently

8. _____ training refers to lowering weight loads that are too heavy for a given individual to lift. a. Assistedb. Breakdownc. Slow d. Negative


0203401LB02B-09-74


9-22

Step 13: Lesson SummaryIt has been one month since new exerciser Valerie first started her fitness plan. Visiting the gym three times a week left Valerie with some initial muscle soreness. But this disappeared as she followed Jaclyn’s instructions regarding proper weight-lifting technique and adequate muscle recovery. Valerie enjoys her newfound energy and the empowerment she feels from her exercise accomplishments—particularly her improved muscle strength and endurance.

Just as Jaclyn suggested, Valerie has regained the physical stamina, flexibility and mobility she enjoyed while working as a teacher and is now able to keep pace with her grandchildren during their frequent visits. Her son and daughter-in-law, both encouraged by Valerie’s fitness progress, signed up for their own memberships at the community health center.

Valerie plans to continue her workouts with Jaclyn and joined both a water aerobics class and a trail-walkers club to increase her physical activity on a day-to-day basis. Thanks to her new lifestyle of fitness, Valerie’s future looks bright, and she looks forward to remaining healthy and active throughout her golden years.

Valerie is an excellent example of the importance of keeping the musculoskeletal system strong and healthy. Her quality of life depends on maintaining healthy bone, muscle and connective tissue. This lesson provided you with valuable information regarding bones and muscles and how these components work together to allow a wide range of physical activities. You also learned how what you’ve read in this lesson will apply to your clients’ fitness goals as you begin your work as a personal fitness trainer and nutritional specialist.

In your line of work, you will have the unique opportunity to introduce clients to the many positive factors that a strong musculoskeletal system can bring to their lives. Adding the benefits of fitness into the lives of others is just one of the many exciting experiences you can look forward to in your new career!

Your next two lessons will further discuss your muscles in action. But before we get to that, take your Quiz to complete this lesson! Don’t forget, if you found parts of this material confusing, reread those sections or give your instructor a call.


Lesson 10Muscles in Action I


● Determine how nutrients affect the way muscles operate.

● Discuss the physiology of muscle fibers and connective tissues.

● Describe the role of the nervous system in muscle activity.

● Identify the types of strength training, as well as sample exercises.

● Explain why muscles become sore and tired and how to alleviate such problems.

Step 2: Lesson PreviewYou have a big day tomorrow! You have to catch an airplane for an important event, and if your morning goes exactly right, you can get to your flight just in time. You’ve done a little planning. You’ve reviewed the route to the airport, you know an alternate route in case the first one is slowed by a traffic jam and your bags are packed. Your kids’ clothes are laid out for tomorrow, their lunches are made and you’ve signed all of their permission slips. You’ve been to the ATM, and your airplane ticket is with your luggage. You’re completely prepared for your trip.

Even if the kids get off to school on time, traffic goes your way and you manage to park in the cheap lot close to your gate at the airport, you won’t make your flight if your car runs out of gas.

Good nutrition is like keeping your car full of gas. When you think of preparing for any event—whether it’s an important meeting with your boss or a 5K road race—you likely focus on a host of details other than what you’ll eat that day, much less what you’ll eat in the weeks prior to that day. But practicing good nutrition is like performing routine maintenance on a car. It makes the rest of your life run more smoothly. In fact, incorporating healthful eating into your daily life lets you focus on other details because you know your body is well fueled.

In this lesson, you’ll get an in-depth look at the fibers in your muscles, the types of connective tissues and their operations and ways to exercise your muscles. You’ll gain a greater appreciation for how hard your body works! And you’ll see that a body that works that hard needs good fuel. So, let’s start learning!

0203401LB02B-10-74


10-2

Step 3: Muscle NutritionYou surely know about comfort food—the food that you eat to soothe an emotional need. For some people, a plate of mashed potatoes is the ultimate comfort food; for others, it’s meatloaf just like mom used to make, eggplant parmesan, fried chicken or chocolate.

But it’s time to redefine comfort food, especially for people who have bodies and use their bodies every day. Well, that includes everyone! Most people want to have more energy and feel better. It doesn’t matter whether you make a living on the basketball court or take dictation in court—you rely on your body. Of course, people who exercise use their bodies more and have greater incentive to pay attention to good nutrition. So, if you think about it, a true comfort food should help your body feel better and work more effectively. After eating a true comfort food, your body should feel better, not sluggish and bloated.

The bad news is that there isn’t a perfect comfort food to make your muscles perform at their best. The good news is that because good nutrition encompasses variety, you don’t have to eat the same thing every single day of your life!

You already know that whether you work your muscles for size or endurance, high-quality protein is crucial to help build and repair muscles. And although carbohydrates are often overlooked, you know that the muscles need them, too. Fats play an important role in the body, but we’ve learned that most people in our country get plenty of fat already. Of the food we eat, about 99 percent of the carbohydrate, 95 percent of the fat and 92 percent of the protein are digested and absorbed. Our bodies are incredibly efficient at using what we give them!

Although no food is magic, it seems that the media hypes a new “perfect” food every week. Even reliable models for healthy eating, like the information you learned in Lesson 5, are constantly updated and reviewed. But setting aside all the hype and theory, let’s look at some basic guidelines for feeding your muscles based on what you want them to do.

Building Strong MusclesYou already know that the most important food component the body uses to fuel a workout is carbohydrates. Carbohydrates also help your body use fat efficiently and support the function of the brain and nervous system.

About 55 percent to 65 percent of your calories should come from carbohydrates. People who exercise more than one hour every day should be at the upper end of the scale; people who exercise moderately should aim for 55 percent to 60 percent. The easiest way to measure this is to count carbohydrate grams, being sure to take in between 1.8 and 2.7 grams of carbohydrate per pound of body weight per day.

After your exercise session, your body’s muscles must recover, and you know that’s where protein comes into play. Protein builds and repairs body tissues, including muscles, ligaments and tendons; plays a role in the synthesis of hormones, enzymes and antibodies; and is important in fluid transport and energy. But remember, protein is only used as a source of energy if you don’t eat enough calories or restrict your consumption of carbohydrates.

Active adults need about 0.36 grams of protein per pound of body weight per day.

0203401LB02B-10-74

Muscles in Action I

10-3

Going the DistanceTo build your endurance, you have to be sure that your body has stored enough glycogen, which comes from carbohydrates.

For most of us, even moderately active adults, the standard recommendation—1.8 to 2.7 grams of carbohydrates per pound of body weight per day—gives us plenty of glycogen. However, people who participate in high-intensity activities, such as marathons or triathlons, may benefit from carbohydrate loading. Do you remember learning about carbohydrate loading in a previous lesson?

The Body at RestYour body digests carbohydrates quickly—they’re through the digestive system in two hours and are then in use. However, protein requires more effort for your body to digest. Digesting protein takes longer and may divert blood to the digestive system from the rest of the body. That’s why when you’re out for a bike ride, it’s better to eat a banana than a hard-boiled egg. It’s easier on your body to eat your protein while you’re resting.

Furthermore, after a moderate- to high-intensity exercise session, it can take 24 hours to fully restore all the glycogen in your muscles. Some research shows that consuming carbohydrates within 30 minutes of an intense exercise session followed by more carbohydrates approximately every two hours helps maximize muscle glycogen. Delaying intake of carbohydrates makes it harder for your body to replenish its glycogen stores. But again, replenishing glycogen is less of an issue for average, active adults who exercise at a low- to moderate-intensity level.

And of utmost importance, don’t forget to drink water! You’ve already learned that thirst isn’t a reliable indicator of water need. A person should drink two cups of water 15 to 20 minutes prior to exercise. You should continue to replace water losses during a workout by drinking one half to one cup of water for every 15 minutes of activity. And just because you stop exercising doesn’t mean that you can stop drinking. As your body cools after exercising, it’s important to keep hydrating.

Supplementing the DietWe’ve already talked a great deal about supplementation in this course. You know by now that sometimes it’s difficult to get all the nutrients your body needs through food alone. That can be true depending on how much time you have and how much of that time you spend selecting and preparing healthy food. Some days, it seems far easier to stop at a convenience store for a donut than it is to fix whole-grain pancakes at home!

Now, let’s take a close look at a few reasons why your clients might want to consider using a vitamin or mineral supplement. We talked briefly about some of these reasons previously, but a little review will be helpful. These reasons include:

● Drinking a lot of coffee—Hot liquids and caffeine can irritate the lining of the digestive tract and interfere with food absorption.

● Drinking a lot of alcohol—It affects how the body absorbs and metabolizes nutrients.

● Smoking—It irritates the digestive tract and increases the need for Vitamin C.

0203401LB02B-10-74


10-4

● Fad dieting—Eliminating all protein, all carbohydrates or all fats from the diet can cause a serious lack of some vitamins.

● Vegetarianism—A balanced diet without any meat or meat products requires a lot of planning and skill to avoid deficiencies in Vitamin B12.

● Food allergies—Allergies to gluten or the condition of lactose intolerance often mean the body can’t digest important sources of thiamine, riboflavin and calcium.

● Stress—Emotional and physical stress can increase the body’s need for B and C vitamins; air pollution can increase the body’s need for supplements with Vitamin E.

● PMS—The irritability, bloating, headaches, lethargy and depression improves in as many as 60 percent of affected women when they take Vitamin B6.

● Lack of sunlight—Those who live in the northern regions or work nights may not get enough Vitamin D, which is required for metabolizing calcium.

Step 4: Muscle Fibers and Connective TissuesYou have already learned a lot about muscles—how they allow you to pick up boxes when you move, how they interact with bones and how they hold the body upright. But muscles have a lot of help as they perform their tasks. First, we’ll look at muscle fibers in detail and then go on to review the muscles’ helpers—connective tissues.

Muscle FibersWe’ve talked about muscle fibers in previous lessons, and you’ll remember that muscle fibers are the cells of the muscle. One muscle fiber is about the diameter of a human hair. These fibers are long—sometimes they run lengthwise for the entire length of a muscle—and cylindrical. Muscle fibers are grouped into bundles of up to 150 fibers, and connective tissue surrounds each bundle.

Remember that a motor neuron or nerve cell stimulates the muscle fibers to contract, which causes muscle movement. One neuron can stimulate several hundred fibers.

In Lesson 9 you learned that muscle fibers come in two types: slow-twitch and fast-twitch fibers. Slow-twitch fibers are used heavily during aerobic activity, while fast-twitch fibers are better suited for anaerobic exercises.

A person with a higher percentage of fast-twitch muscles will be able to perform better in speed and power events, such as power lifting or sprinting, than a person with a higher percentage of slow-twitch muscles, who will excel at endurance events. You can’t make muscle fibers change type no matter how much you train. Therefore, genetic makeup largely determines the type of sport at which a person excels. However, it is possible to improve the aerobic and explosive capacity of fast-twitch muscle fibers through strength training. It’s also possible to improve the aerobic capacity of slow-twitch muscle fibers through aerobic training.

0203401LB02B-10-74

Muscles in Action I

10-5

Connective TissuesAlthough we may think of the skin as the part of the body that holds everything together, this actually isn’t true. Instead, connective tissue links muscles and bones and generally allows our bodies to move without falling to pieces. This fibrous coating covers the skeletal muscles. We’ve talked about connective tissues in previous lessons, but now let’s do a quick review, as well as add some new information.

Collagen fibers are the primary component of the musculoskeletal connective tissue. In Lesson 6, you learned to think of collagen as the substance that glues an injured area back together.

Type I collagen is the protein that makes up bones, tendons and ligaments. Collagen fibers are organized into connective tissue in much the same way that muscle fibers are bundled into muscles. However, muscles are surrounded by a protective membrane, while collagen fibers aren’t. Bundles of collagen develop first because the proteins are attracted to each other. Then, the bundles are chemically linked to become a stable unit.

Collagen bundles can join lengthwise to form tendons or ligaments; they also can form in long sheets in the bone and the fascia of muscles. Regular physical activity can actually strengthen the connective tissue, improving both its quality and quantity.

Aerobic exercise alone doesn’t seem to increase the proportion of collagen in connective tissue; however, high-intensity exercise, including weight-lifting, does increase the proportion of collagen. Also, as muscle strength increases, the muscles pull harder on the connected bones and cause an increase in bone mass at the point where the tendon and bone meet. These processes serve to strengthen and stabilize the way the body moves.

Tendons, Ligaments, Fascia and CartilageYou already know that tendons connect muscle to bone and ligaments connect bone to bone. And you probably remember that fascia wraps our organs and muscles, supporting them and giving them their shape. In a muscle, fascia organizes different levels of muscle fibers. At the ends of a muscle, the different layers of fascia join to form a tendon.

Ligaments have elastin, a protein that allows for flexibility. Ligaments have to stretch to let the muscles function normally. Tendons and ligaments have a direct blood supply, which helps them heal following an injury. However, because they have less blood supply than muscles, tendons and ligaments heal more slowly than muscles after they are stressed and injured.

Remember that the three main functions of cartilage are to:

● provide a smooth surface between the bones in a joint, such as the knee

● serve as a shock absorber for the joint

● help attach muscles to the skeleton

Cartilage is very dense and is made up of cells that are embedded in a firm foundation. It doesn’t have its own blood supply, which means that cartilage doesn’t heal easily after it’s injured.

0203401LB02B-10-74


10-6

Step 5: The Nervous System The nervous system plays a crucial role in muscular contraction. You probably remember learning about the motor unit and its role in muscle contraction in Lesson 9. Well, your muscles may be strong, but they need to be told what to do. You know that muscles can’t contract without an impulse from the nervous system. And without the centralized control function of the brain, any coordinated movement of many different muscles is impossible.

The nervous system is divided into two parts:

● the central nervous system—the brain and spinal cord

● the peripheral nervous system—nerves that connect the extremities to the central nervous system

The central nervous system is vital for human life. Therefore, bone protects it. Remember that the brain is encased in the skull, and the vertebrae in the spinal column protect the spinal cord. The central nervous system is like a military command and control center, receiving and sending information to all units in the field.

Meanwhile, the peripheral nervous system is made up of 12 pairs of cranial nerves—two in the brain and 10 in the brain stem—and 31 pairs of spinal nerves that run from the spinal cord to the rest of the body—from the tips of your fingers to the tips of your toes.

Nerve cells carry impulses or messages to muscles, telling specific muscles to contract. These impulses come either from the central nervous system or from receptors, which are nerve cells with special functions. Different receptors are wired to respond to changes in body position, pain, temperature and pressure. Sensory nerve cells carry information from the peripheral receptors to the brain and spinal cord. Motor nerve cells carry impulses from the central nervous system to make the body respond to information from the receptors. If you’ve ever yanked back your hand after brushing a hot burner, you’ve experienced receptor nerves.

In fact, coordinated movements aren’t all that different from the hot burner withdrawal reflex. When your body moves in an organized way—like walking, for example—the peripheral and central nervous systems initiate the movements, guide the movements and monitor what’s happening. Also, when your muscles are tired and you’re feeling the burn of exercise, the pain is your nervous system at work, telling you that your muscles are fatigued and it’s time to rest.

Step 6: Strength Training in PracticeNow, let’s get into the specifics of types of muscle movement and how you can exercise the muscles using those movements.

Muscle MovementEvery time a nerve impulse stimulates a muscle, the muscle contracts. However, a contracting muscle isn’t necessarily getting shorter along its whole length. A concentric contraction, also called a positive contraction, shortens the muscle and develops tension. An eccentric contraction or negative contraction develops tension while actually lengthening the muscle. In either case, the muscles are moving against external resistance. If the force of the contraction is greater than the external resistance, it’s a concentric contraction. If the force of the contraction is less than the external resistance, it’s an eccentric contraction.

0203401LB02B-10-74

Muscles in Action I

10-7

Think of a pushup. When your biceps, triceps, pectorals and other shoulder and arm muscles push you up from the floor, their contraction is greater than the resistance of gravity pulling on your body weight, and the muscles are performing a concentric action. To move, they must overcome a stressor.

When those same muscles are lowering you slowly to the ground—trying not to drop you flat on your face—they are creating the resistance as they pull against gravity. Like brakes, they slow the weight’s descent. That action is eccentric action.

Exercising MusclesEveryone moves throughout the day, and to move, we use muscles. Dancing, snapping your fingers, waving to your neighbor outside washing his car—all of these activities use muscles. However, to build strength in specific muscles, you must be sure to give them appropriate exercise. You can exercise muscles to build strength in three ways:

● with isometric exercises

● with isotonic or dynamic resistance exercises

● with isokinetic exercises

Isometric ExercisesIn the previous lesson, you learned that isometric contraction occurs when a muscle tries to shorten but shortening is prevented. In isometric exercises, your muscles contract at high intensities but don’t change their length. The most common way to get that contraction is to press against an immovable object, such as a wall or piece of furniture. Your muscles develop strength at that point in their range of motion.

Let’s say a swimmer wants to increase her arm muscle strength. One isometric exercise she could do is to place her hands on top of a chest-high object—her dresser, for example—and press down as hard as she can for a count of 10. A series of repetitions of this exercise, with rest in between, would increase the strength of her musculature when it is in that exact position—but ONLY when it is in that exact position.

To increase the strength of her back, shoulder, chest and arm muscles as they work all along the length of her freestyle stroke, she would have to perform a series of isometric presses—one on an immovable object just above her head, one at chest height, one at waist height and one at the tops of her thighs.

Clearly, one advantage of isometric exercises is that they don’t require fancy equipment. However, they do have disadvantages. First, they significantly raise blood pressure because blood flow is nearly at a full stop in the muscle that’s exercising. Second, increasing strength along the length of the muscle requires significant planning. Third, doing isometrics can be monotonous, in part because you don’t have the psychological satisfaction of feedback. There’s no way to measure that you’re able to press harder than you did the last time you performed such an exercise, whereas when you’re lifting a free weight, you know you’re stronger when you can go from a three-pound dumbbell to a five-pound dumbbell. We’ll give you some examples of isometric exercises a little later in this lesson.

0203401LB02B-10-74


10-8

Isotonic ExercisesIn Lesson 9, you learned that isotonic contraction is the shortening of muscles. Isotonic exercises also are known as dynamic resistance exercises, and these exercises provide external resistance throughout the ROM of a muscle. The muscle works to overcome that resistance. There are two types of dynamic resistance exercises: constant and variable.

Traditional free weights and stacked-weight systems provide constant resistance. The amount of weight you’re trying to lift determines how hard your muscle has to work. Also, a 10-pound weight is a 10-pound weight whether you’re holding it straight out in front of you or down at your side. However, because of the changes in the angles of your muscles as they move, the amount of work your muscles have to do is different at different points in the exercise. For example, if you’re doing squats holding a barbell on your chest, you have to exert more force at the bottom of the squat than you do when you’re near the standing position, simply because of the angles.

That’s part of the reason why variable resistance exercise machines were developed. With these machines, levers, cams or linkage systems change as your muscle moves. They provide less resistance when your muscles are in weaker positions and more resistance when your muscles are in stronger positions. Because the machine itself makes these adjustments, your muscle effort is constant throughout the ROM of the exercise. Still, the amount of external resistance is what determines how hard your muscles must work. Specially designed weight machines, like Nautilus, provide this variable resistance.

An advantage to dynamic resistance exercises is that they include extensive feedback. After all, visible improvement in strength can be a powerful incentive to continue training. Furthermore, exercises using constant resistance are relatively easy to do. The equipment is available at most gyms, and a little creativity can produce less-expensive options, like lifting cans of food instead of free weights. Some experts believe that the movements of constant resistance exercises are more like those you would normally do while performing a sport, which makes them more effective in developing strength you can immediately apply to an activity.

A primary disadvantage of constant resistance exercises is that you can’t always train through a full ROM. Although variable resistance exercises overcome that disadvantage, they aren’t universally available, which often makes them a less-popular choice. Using machines means that muscles surrounding the ones you’re working get a free ride—the machine determines the motion you’ll perform, and the muscles that would normally work to provide stability and keep the exercising muscles supported aren’t working. Some trainers prefer that their clients use free weights for that reason. You’ll see some examples of isotonic exercises in a moment.

Isokinetic ExerciseIn isokinetic exercises, the speed of the movement matches the amount of resistance. The more muscle force you apply, the more resistance you encounter. If you pull harder, you will pull against more resistance.

Equipment for isokinetic exercises includes hydraulic equipment and some electronic resistance machines. Generally, the equipment provides resistance only when your muscles are performing concentric actions, though some electronic equipment also works during eccentric actions. You can get detailed feedback using isokinetic exercises. Also, they seem to work without producing much muscle soreness. However, the equipment is costly and not widely available.

0203401LB02B-10-74

Muscles in Action I

10-9

Step 7: Examples of Isometric ExercisesOne of the primary benefits of isometric exercises is that it is possible to find ways to do them in a number of places, not only a fitness club. The equipment you need is minimal—a weight or an immovable structure may be all it takes. Here are some examples.

Stand with your legs shoulder-width apart. Holding a weight, raise your arm out to the side until it is at shoulder height. Hold your arm there for a count of 10 to 20 seconds. The isometric part of the exercise occurs when you’re holding the weight still, not when you’re moving it into position.

In another example, select a weight as if you were going to perform a traditional biceps curl. In the middle of the curl, when your upper arm and lower arm are at a 45-degree angle, hold the weight still. Hold it for a count of 10 to 20 seconds. Again, the point at which you stop moving is the point at which the isometric exercise begins.

Another well-known isometric exercise is the wall sit. This exercise is often used to strengthen quadriceps muscles before snow skiing season. Standing with your back against the wall, slide downward, carefully walking your feet out until your thighs and lower legs are at a 45-degree angle. Hold the position for a count of 10 to 20 seconds. As you hold yourself there, you’re working against gravity by pressing against the wall. If you press through your heels and contract your rear muscles, you can work both the front and back of your thigh.

Step 8: Examples of Isotonic or Dynamic Resistance Exercises

Isotonic or dynamic resistance exercises can be as high tech or as low tech as you and your clients want them to be. You can use weight machines with either constant or variable resistance, free weights or your body’s own weight.

You can perform any number of dynamic resistance exercises with weights. Biceps curls, shoulder shrugs and shoulder or arm raises are all easy upper-body examples. If you fill a bucket with sand, you can sit on a raised surface, hook the bucket handle over your toe and straighten your leg for leg extensions. If you have access to a sturdy bar, you can do pullups.

You don’t even need special weights for dynamic resistance exercises; you can simply rely on the weight of your body and gravity to serve as forces to resist. Pushups—both the traditional face-down kind and the face-up style that exercise the triceps—are a familiar dynamic resistance exercise. Squats, whether on a flat surface or uneven surface, also rely on body weight to add resistance. Toe raises, in which you stand on a step and raise and lower your body weight by pointing and flexing your toes, are another example. And you can’t forget the old standby, situps.

0203401LB02B-10-74


10-10

Step 9: Muscle Soreness and FatigueHave you ever noticed that a softball game itself is really fun, but you pay for it a day or two later with sore, stiff muscles? Your muscles feel fatigued because you’ve worked them—that seems relatively simple. You’re tired when your workday is finished, too! But how tired your muscles get depends on the intensity and duration of the exercise you’ve just completed. If you’ve just done the 100-meter dash, your muscles are tired because they’re out of ATP; if you’ve just run a marathon, your muscles are tired because they’ve run out of glycogen. Dehydration is another factor that can cause fatigue.

Unfortunately, muscles do get sore. Fortunately, there are a few things you can do to help prevent it.

Muscles get sore at two different times. The first time is during or immediately after exercising. You know that lactic acid building up in the muscles and irritating nerve endings causes this type of soreness. Within half an hour to an hour after you stop exercising, the bloodstream removes most of this lactic acid.

That’s one reason why it’s a good idea to cool down after exercising. Keeping the blood flowing allows these waste products to be removed more quickly. Another effective way to alleviate the soreness that occurs while exercising or immediately after exercise is to stretch the muscles.

Note that pain during or immediately after exercise may also indicate an injury to the muscle or connective tissue, so be sure to pay attention to your body and your clients’ bodies.

The other time you notice muscle soreness is a little while after you’ve finished exercising. This type of soreness can last for one to three days and is generally called delayed onset muscle soreness or DOMS. Minor tears in the connective tissues that hold muscle fibers together and in the muscle cell membranes cause this type of soreness.

Again, stretching can help. Massage also helps your muscles get rid of the waste products that happen with the microscopic trauma they’ve experienced. You can do gentle stretching every day after your muscles have been warmed up. If you want to stretch on a day when you’re not training, take a warm shower or do a gentle warm-up before you stretch.

Many other theories and remedies exist to combat muscle fatigue and soreness. Because they replenish carbohydrates and trace minerals used in exercise, sports drinks can alleviate feelings of fatigue and muscle soreness. For a time, it was thought that low potassium levels in the muscles were the primary cause of soreness and that eating bananas helped. Warm baths in a jetted or plain tub with or without Epsom salts may help increase blood flow and reduce soreness. Even if the remedy doesn’t instantly cure the problem, it’s pleasant enough. And as you keep exercising, your tendency to experience delayed onset muscle soreness diminishes as your muscles become more fit.

Wow! You’re almost finished with your first lesson about muscles in action. Think of how much you’ve learned. Now, let’s pause for a moment and review what you’ve read.

0203401LB02B-10-74

Muscles in Action I

10-11


1. Of the food we eat, about _____ percent of the carbohydrate is digested and absorbed.a. 99b. 95c. 92d. 50

2. The best time to eat a protein-rich meal is _____.a. just before exerciseb. during warm-upc. during the aerobic part of your workoutd. after your body is cool and at rest

3. Which of the following is NOT a good reason to take a dietary supplement? a. You’re suffering from PMS.b. You’re a smoker.c. You heard the supplement advertised on TV.d. You follow a vegetarian diet.

4. Both collagen fibers and muscle fibers are arranged _____.a. in criss-cross patterns for strengthb. in lengthwise bundlesc. to have direct blood supplyd. to lie deep within the bone

5. _____ a direct blood supply, allowing healing following an injury.a. All connective tissues haveb. Fascia hasc. Cartilage hasd. Tendons have

6. The skull and vertebrae protect the _____.a. peripheral nervous systemb. central nervous systemc. fasciad. musculature

0203401LB02B-10-74


10-12

7. _____ nerve cells carry impulses from the central nervous system to make the muscles respond to information from the receptors. a. Centralb. Peripheralc. Motord. Sensory

8. An eccentric contraction _____.a. has no impact on the muscleb. shortens the muscle c. develops tension while lengthening the muscled. causes the muscle to spasm uncontrollably

9. Isometric muscle exercises _____.a. require special machineryb. raise the body’s blood pressurec. are expensive to scheduled. move a muscle through its entire range of motion

10. When you perform dynamic resistance exercises, you get _____ feedback.a. nob. somec. extensived. not particularly meaningful

11. Isokinetic exercises _____.a. match the speed of the muscle’s movement with the amount of resistance it encountersb. can be performed with free weightsc. can be performed with items you can find around the housed. include situps and pushups

12. Stretching and massage are ways to _____.a. prevent muscle sorenessb. prevent injuryc. build muscle massd. build endurance


0203401LB02B-10-74

Muscles in Action I

10-13

Step 12: Lesson SummaryYou are so close to finishing your second pack of lessons! By now, you should be getting a clearer picture of what your new career involves. In your work as a personal fitness trainer and nutritional specialist, the material you’ve read here will certainly help you help your clients.

We reviewed how nutrients affect the way muscles operate and the importance of connective tissues in the body. We talked in detail about muscle fibers, and you learned the role of the nervous system in muscle activity. You now know the different types of strength training, and you learned some sample exercises as well. You can practice these exercises to get hands-on experience. Lastly, we studied why muscles become sore and tired and the different ways to alleviate such problems.

In your next lesson, you’ll learn more about the amazing muscles in your body. And as you begin your next pack, you’ll begin to learn about the specific muscle groups. You’ll also get some more real-world experience as you practice performing a host of exercises to work those different muscle groups.

Take a few minutes to review this material before you begin your Quiz. And don’t forget, your instructor is only a phone call away if you have questions!


Good job! You’ve already learned so much. You deserve a break and a pat on the back. Chances are, you’re beginning to look at your body a little differently. Where you once saw arms, you now see muscles, tendons, bones and skin. Where you once saw simple breathing, you now see oxygen delivery, cardiac output and aerobic energy production.

Muscles are more than just bumps under the skin. They allow you to walk, talk, breathe and turn pages. Without muscles, you could never get this far in the course! Everyone has muscles, and keeping those muscles in shape is so important. Just think. Everyone is a potential customer. There isn’t a person alive who couldn’t make use of your skills. And this, of course, means more money and opportunities for you!

Personal training is an active career, and your body is one of your best selling tools. Practice what you learn. By staying in shape, you’ll not only feel good about yourself, but you’ll be an inspiration for your clients, too.

So grab your jump rope, ride your bike or get on that treadmill. It may look like you’re running in place, but you’re speeding toward your new career as a personal fitness trainer and nutritional specialist.

0203401LB02B-10-74


10-14

0203401LB02B-AK-74 AK-1

Answer Key

Lesson 6

Practice Exercise 6-11. To get the most out of her exercise program, a person should eat at least c. five times a day.

2. A body that is in famine mode is likely to b. store more of the food it receives as fat.

3. Which of the following is NOT a macronutrient? c. Sugar

4. When exercising to build muscle mass, it is important to consume enough a. complete protein.

5. The primary component of muscle tissue is c. water.

6. One way to prevent feeling hungry throughout the day is to d. eat smaller, more frequent meals.

7. The b. soybean is the only non-animal source of complete protein.

Practice Exercise 6-21. b. Peptide bonds are the chemical bonds between the amino acids.

2. An example of a complementary protein is c. peanut butter with bread.

3. How many grams of protein does a 110-pound woman need to consume each day? a. 40

4. d. Disaccharides are carbohydrates composed of two simple sugar units.

5. The body prefers to use b. carbohydrates as its primary source of energy.

6. The average person stores enough glycogen to fuel c. 90 minutes of exercise.

7. During ketosis, the body burns a. fat as an energy source.

8. A a. positive nitrogen balance tends to indicate muscle growth.

9. d. Fatty acids are composed of several hydrogen and carbon atoms.

10. Lipoprotein is a lipid that contains a b. protein component.

0203401LB02B-AK-74


AK-2

Practice Exercise 6-31. d. Iron-deficiency anemia is perhaps the most common deficiency in the United States.

2. Which of the following groups is most at risk for developing osteoporosis? b. Asian females

3. Smokers require more of which vitamin than nonsmokers? c. Vitamin C

4. a. Low blood sugar results from failing to eat enough of the right foods or waiting too long between meals.

5. To which hormone are anabolic steroids most closely related? b. Testosterone

6. Which of the following is a consequence of anabolic steroid use in adolescents? d. Stunted growth

0203401LB02B-AK-74

Answer Key

AK-3

Lesson 7

Practice Exercise 7-11. The two gases that the respiratory system uses are b. oxygen and carbon dioxide.

2. A spirometer is a device used to c. evaluate respiratory function.

3. d. Gas transport is the process of moving oxygen in red blood cells from the lungs to the cells in the rest of the body and moving carbon dioxide back again.

4. Maximal oxygen uptake is d. the greatest amount of oxygen that your body can use at the cellular level.

5. Which of the following does NOT stress your respiratory system? c. Talking

6. An electrocardiogram measures a. the electrical conductivity of the heart.

Practice Exercise 7-21. c. Water-based activities provide excellent benefits for people who have joint problems or who

have been injured doing some other activity.

2. Generally, lap swimmers prefer d. cooler water than recreational swimmers.

3. Stair machines and elliptical machines a. provide weight-bearing, low-impact exercise.

4. Duration refers to c. the amount of time in an exercise session that aerobic conditioning is occurring.

5. a. During warm up you can make the mental transition to exercising.

6. Cooling down b. reduces the likelihood that muscles will spasm or cramp.

7. Your muscles may be tired and feel sore while exercising because c. lactic acid is irritating nerve endings.

0203401LB02B-AK-74


AK-4

Lesson 8

Practice Exercise 8-11. Anatomy, physiology and pathology are included in the study of life called human biology.

2. When there are changes in the form of an organ, such as size, shape or color, they’re called morphological changes.

3. The science of the structure and relationships of body parts is called anatomy.

4. The study of the function of body parts is called physiology.

5. The study of disease is called pathology.

Practice Exercise 8-21. When the arms are at the side, the palms of the hands are facing forward and the thumbs are

pointing outward, the body is in the anatomical position.

2. A transverse section is also called a horizontal section.

3. A parasagittal section divides the body into unequal left and right portions.

4. A frontal section is also called a coronal section.

5. A horizontal section divides the body into superior and inferior portions.

6. A longitudinal section is also called a sagittal section.

7. A frontal section divides the body into anterior and posterior portions.

8. A midsagittal section divides the body into equal left and right portions.

9. A midsagittal section is also called a median section.

10. A section is a mental slice or cut.

0203401LB02B-AK-74

Answer Key

AK-5

Practice Exercise 8-31. c. anterior—in front of

2. i. posterior—in back of

3. d. distal—farther away from the center

4. e. external—outer, outside

5. f. inferior—below

6. g. proximal—nearer to the center

7. a. internal—within, inside

8. j. superior—above, upward

9. b. medial—toward the middle

10. h. peripheral—at or near the edge

Practice Exercise 8-41. The synovial joint is the most common type of joint in the body. The hip and shoulder are in this

class and are designed to allow a wide range of motion.

2. The fibrous joint type includes all joints where the surfaces of the bones are in almost direct contact and are not moveable.

3. Circumduction is movement of a body part so that its end follows a circular path. It is a combination of extension, adduction, flexion and abduction and occurs only in the shoulder and hip joints.

4. The cartilaginous joint allows only slight movement.

5. Supination involves turning the hand so that the palm faces upward.

6. Opposition occurs when the thumb pad moves toward and touches other anterior pads of the fingers.

7. Eversion involves turning the foot laterally so the sole faces away from the body.

8. Retraction occurs when a body part moves posterior or backward.

9. Depression is movement inferiorly or downward.

10. Extension is the opposite of flexion and causes the parts at the joint to straighten out or open so that the angle between the body parts is increased and the parts move farther apart.

0203401LB02B-AK-74


AK-6

Lesson 9

Practice Exercise 9-11. The b. skeletal system is the backbone of the body.

2. The solid, outermost layer of bone tissue is called a. compact bone.

3. Which of the following is NOT an example of a cartilaginous joint? c. The joints in the head and the trunk

4. The cells that compose cartilage are called a. chondrocytes.

5. Bone interacts with the thyroid gland and the parathyroid gland to provide a. calcium and phosphorus homeostasis.

6. The cloud of bone and collagen that forms around the site of a fracture is called a c. callus formation.

7. The d. skull is the part of the skeleton that encases the brain and the special sense organs, as well as forms the face.

8. The bones in the extremities or limbs and the pelvis are called the b. appendicular skeleton because they are appendages of the axial skeleton.

Practice Exercise 9-21. Which type of muscle function are you engaging when you bend your leg, make a fist or

consciously move any part of your body? a. Voluntary

2. Muscle tissue usually carries out voluntary muscle function. c. Skeletal

3. Muscles located in the b. internal organs usually carry out involuntary muscle functions.

4. The ability of muscle cells to shorten or try to shorten is a. contractility.

5. The ability of the muscle to respond to a stimulus is d. irritability.

6. The gap between the motor end plates of a nerve cell and a muscle cell is called b. a synapse.

7. The continuing contraction of small groups of muscle fibers in every muscle is called a. muscle tone.

8. The d. trunk muscles help protect many of our delicate internal organs.

0203401LB02B-AK-74

Answer Key

AK-7

Practice Exercise 9-31. To generate a force on an external object, a muscle must be attached to a. a bone at both ends.

2. The muscle that most directly generates the force for a particular movement is referred to as the b. agonist.

3. The muscle most involved in slowing or stopping a movement is referred to as the a. antagonist.

4. On average, men have more muscle tissue than women as a result of men’s higher levels of which hormone? c. Testosterone

5. Which type of muscle fiber is used most heavily during aerobic activity? a. Slow-twitch

6. The amount of weight that is used during resistance training is the b. load.

7. Lifting a load b. at a fast pace puts extra stress on the joints and requires less overall control of the load.

8. d. Negative training refers to lowering weight loads that are too heavy for a given individual to lift.

0203401LB02B-AK-74


AK-8

Lesson 10

Practice Exercise 10-11. Of the food we eat, about a. 99 percent of the carbohydrate is digested and absorbed.

2. The best time to eat a protein-rich meal is d. after your body is cool and at rest.

3. Which of the following is NOT a good reason to take a dietary supplement? c. You heard the supplement advertised on TV.

4. Both collagen fibers and muscle fibers are arranged b. in lengthwise bundles.

5. d. Tendons have a direct blood supply, which allows healing following an injury.

6. The skull and vertebrae protect b. the central nervous system.

7. c. Motor nerve cells carry impulses from the central nervous system to make the muscles respond to information from the receptors.

8. An eccentric contraction c. develops tension while lengthening the muscle.

9. Isometric muscle exercises b. raise the body’s blood pressure.

10. When you perform dynamic resistance exercises, you get c. extensive feedback.

11. Isokinetic exercises a. match the speed of the muscle’s movement with the amount of resistance it encounters.

12. Stretching and massage are ways to a. prevent muscle soreness.

prsona itnss ainrr utritiona ciaist - u.s. career...

Documents