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Test Title
W.I.T.S. Personal Trainer Certification Lecture Three:
Nutrition; Exercise Prescription for Weight Management;
Exercise Prescription for Cardiovascular Fitness
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Good Nutrition• Malnutrition: under, over or unbalanced consumption of nutrients leads to disease.• Good nutrition results from eating the
right food, with the right nutrients, in the right quantities.
• Poor nutritional choices have been linked to CVD and cancer.
• Fitness professionals can convey information about good nutrition, but may not prescribe detailed diets.
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The Six Essential Nutrients• Macronutrients (needed in large
quantities):– carbohydrate– fat– protein– water
• Micronutrients (needed in small quantities):– vitamins– minerals
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The Six Essential Nutrients
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Carbohydrate
• Plant-based foods (fruits, vegetables, grains, seeds, nuts).
• Carbohydrates are broken down to glucose.
• Body’s preferred source of energy for physical activity and mental function.
• 1 g carbohydrate yields 4 kcal. 5
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Carbohydrate
• Nutrient Density: refers to the amount of minerals, vitamins and fiber found in a carbohydrate food source.
• Glycemic index: used to describe how quickly a food elevates the blood glucose level after ingestion.
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Carbohydrates• Simple Carbohydrates:
– mono- and disaccharides – break down quickly to glucose – soft drinks, juice, candy, processed foods,
refined grains
• Complex Carbohydrates: – nutrient-dense polysaccharides – break down slowly to glucose – fresh whole fruits, grains, vegetables, nuts,
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Fat• Fat performs many vital functions:
– temperature regulation– protection of vital organs– distribution of vitamins A, D, E, K– energy production– formation of cell membranes– hormone production
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Fat
• Triglycerides:– the primary storage form of fat in the
body– composed of three fatty acid chains
bound to a glycerol backbone– majority stored in adipose cells
• 1 g. fat yields 9 kcal• 1 pound fat = 3500 kcal
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Fat• Phospholipids: Important
constituents of cell membranes.• Lipoproteins: Allow fat to travel
through the bloodstream.• Cholesterol:
– ingested in the diet and manufactured in the body
– used to form cell membranes and make hormones
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Fat• Saturated Fat
– high intake linked to CVD• Trans Fat
– CVD and obesity• Unsaturated Fat• Essential Fatty Acids
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Protein• Amino acids combine to form proteins. • Protein serves a variety of roles in the
body: – provide enzymes for metabolism – enable muscle contraction – act as connective tissue – promote blood clotting – act as messengers for hormones like human
growth hormone • 1g protein yields 4 kcal.
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Protein
• 8 essential amino acids that the body cannot make, and which must be gotten from food.
• 0.8 g of protein per kilogram of body weight is generally adequate.
• Protein can be supplied by both meat and vegetables.
• Vegetarians should consume complementary proteins.
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Vitamins
• Vitamins are organic substances essential to the normal functioning of the human body.
• Fat-soluble vitamins are A, D, E, and K.
• Water-soluble vitamins are B and C.
• Antioxidant vitamins are thought to help ward off disease.
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Minerals• Inorganic elements that serve a variety of
functions in the human body. • Most consume inappropriate amounts of
calcium, iron, and sodium. – Your body uses calcium for cardiac and skeletal
muscle function. – Adequate Ca2+ promotes bone health and can prevent
osteoporosis. – Dairy products, dark green vegetables, and some nuts
are good sources of Ca2+.
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Iron• Used by the body to make hemoglobin, the O2-
carrying protein in RBCs. • Deficiency may lead to anemia. • Premenopausal women should ingest 18 mg of
iron each day to offset monthly loss of RBCs. • Good sources of iron are red meat, eggs,
spinach, legumes, and prune juice.
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Sodium
• Sodium is a mineral that many Americans over-consume.
• Sodium is found in most processed foods.
• Sodium intake should be limited to no more than 2,300 mg a day.
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Water• Makes up 60%+ of total body weight. • Creates the environment in which all
metabolic processes occur. • A person should ingest 1 to 1.5 ml of
water for each kilocalorie expended each day.
• Adequate intake for men is 3.7 L · day–1 and for women is 2.7 L · day–1.
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Dietary Assessment• Food logs can be useful in learning about
a person’s food intake.
• A fitness professional can often provide general information on healthy eating. – Contact a R.D. for specific dietary
considerations.
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Dietary Guidelines For Americans
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• • Help people make healthy food choices
• Focus on lowering the risk of chronic disease and promoting health
• Encourage most people to eat fewer calories, be more active
• Identify a variety of healthy eating patterns
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Daily Nutritional Values• Daily values are used in food labeling to
help consumers understand the nutritional quality of foods.
• Food labels must contain information about total calories, fat (including saturated fat), cholesterol, sodium, carbohydrate (including dietary fiber), protein, and various vitamins and minerals.
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Nutrition Facts Label
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Lipoproteins and CVD Risk • LDL Cholesterol: “bad” cholesterol
• linked to arterial plaque and CVD• formed from dietary saturated fat
• HDL Cholesterol: “good” cholesterol• helps prevent arterial plaque build-up• manufactured in the liver
• Total Cholesterol: • total amount of HDL and LDL• expressed as mg·dl
• Triglycerides:• fatty acids circulating in the blood stream
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Hydration for Exercise• 14 to 20 oz (400-600 ml) of water 2 hr
before exercise • 7 to 10 oz (200-300 ml) 10 to 20 min
before exercise • 6 to 12 oz (180-350 ml) every 15 to 20 min
during exercise • 16 to 24 oz (475-700 ml) of fluid after
exercise for every pound (0.45 kg) of weight lost
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Protein Intake for Athletes
• Aerobic athletes training intensely : – 1.2 to 1.4 g of protein per kg of weight.
• High intensity-volume resistance training: – 1.6 to 1.7 g per kilogram of body weight.
• Best obtained via a healthy diet rather than amino acid supplements.
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Carbohydrate and Athletes
• Athletes should obtain 60% to 65% of their calories from carbohydrate.
• In preparation for competition, carbohydrate loading can be useful. – Carbohydrate loading consists of tapering
activity and ingesting large amounts of CHO in the days leading up to competition.
– Rest completely on the day before competition.
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Ergogenic Aids • Some may not be harmful but provide no athletic
edge. • Some provide an edge but are banned. • Some lead to health risks. • Higher-than-RDA levels of vitamins and minerals
do not appear to provide a competitive edge. • Creatine phosphate may enhance high-intensity
exercise performance but long-term effects are unknown.
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Female Athlete Triad
• Condition characterized by disordered eating, amenorrhea, and osteoporosis.
• Widespread among athletes, especially those whose sport emphasizes or requires low body weight (swimmers, gymnasts, dancers, rowers, and others).
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Etiology of Obesity • The prevalence of obesity continues to rise.
• Causes of obesity are often not simple to identify.
• Genetics plays a role, but lifestyle choices (e.g., food intake and caloric expenditure) are the most important factors.
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Prevalence of Obesity
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Energy and Caloric Balance
• Energy Balance: – Energy consumed – energy expended
• Positive caloric balance – Caloric intake > caloric expenditure – Leads to weight gain
• Negative caloric balance – Caloric intake < caloric expenditure – Leads to weight loss
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Daily Caloric Need
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Resting Metabolic Rate
• Calories expended to maintain body during resting conditions.
• Represents 60% to 70% of daily caloric need.
• Measured using indirect calorimetry. • Is proportional to body weight. • Decreases with age. • More calories are needed to sustain
muscle than are needed to sustain fat. 35
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Changing Lifestyle to Promote a Healthy Weight
• Reduce total calories.
• Reduce fat intake.
• Increase physical activity.
• Change unhealthy eating behaviors.
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ACSM Recommendations for Weight Management
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• Weight-loss goal of 1 to 2 lb per week• Weekly deficit of 3,500 to 7,000 kcal (1 lb
fat = 3,500 kcal)• Moderate caloric restriction plus
exercise• Limit fat intake to <30% of daily
calories• Aim for minimum 150 minutes of
physical activity per week• 200 to 300 minutes per week will likely
produce more benefits
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Exercise Prescription for Weight Management
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• Frequency: 5 to 7 days per week• Intensity: initially 40-60% HRR
progress to >60% HRR• Time: initially 30 min/day progressing
to 60 min/day• Type: Aerobic to target large muscle
groups and facilitate caloric deficit, resistance training to help maintain fat-free mass
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Strategies for Successful Weight Loss
• Keep records. • Plan meals and snacks. • Solicit support. • Set specific goals. • Develop a reward system. • Avoid self-defeating behaviors. • Combine moderate caloric restriction with
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Gimmicks and Gadgets for Weight Loss
• Quick fixes are often inappropriate long-term solutions to weight control.
• Saunas and sweat suits merely contribute to dehydration.
• Electrical stimulators for the abdominal muscles often use unsubstantiated claims.
• Spot reduction is a myth that certain exercises can cause weight loss in targeted areas.
• Fad diets may lead to short-term weight loss but rarely lead to long-term success.
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Disordered Eating Patterns
• Eating Disorder: A clinically diagnosed condition in which unhealthy eating patterns may lead to severe declines in health, and even to death.
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Disordered Eating Patterns• Anorexia Nervosa
• Bulimia Nervosa
• Binge-Eating Disorder
• Disordered Eating
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Signs of Disordered Eating • Preoccupation with food, calories, and weight. • Concerns about being or feeling fat, even when
weight is average or below average. • Increasing self-criticism of one’s body. • Secretly eating or stealing food • Eating large meals, then disappearing or making
trips to the bathroom • Consumption of large amounts of food not
consistent with the individual’s weight. – Please review your reading for more signs.
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Strategies for Weight Gain • Increase caloric intake by 200 to 1,000 kcal ·
day–1. • Increase the number of healthy snacks
consumed. • The majority of additional calories consumed
should be complex carbohydrate. • Add resistance training to the daily routine. • When training intensely, be sure to consume
daily 1.5 g of protein for each kilogram of body weight.
• Increase consumption of milk and fruit juices.
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Physical Activity, Exercise and CRF
• Linked to reduced risk of chronic disease and death.
• One of the top 10 health indicators.• As CRF increases, risk of death
decreases.
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Exercise Dose and Effect• Dose (amount) of exercise
prescribed is relative to desired effect (response) for an individual.
• The dose for elite performance is different than the dose for functional health.
• Fitness professionals need to identify clients’ goals, in order to prescribe the appropriate dose of exercise. 46
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Potency and Slope• Potency: (intensity)
– Ability of the exercise to bring results.– High intensity exercise may be done
less frequently than moderate.
• Slope: – Reflects how much of an effect results
from a change in dose.– Changes can be short-term or long-
term, depending on the effect being measured.
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Maximal Effect and Variability
• Maximal effect– A specific dose of exercise may be
effective for some, but not others.– Moderate exercise improves risk
factors, but strenuous exercise can modify or reverse risk factors and improve VO2 max.
• Variability – A specific dose of exercise may elicit
varying effects from one individual to another; and in one individual, depending on circumstances.
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Side Effects
• Just like a drug, exercise may have adverse side effects, including increased risk of injury or death.
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Characteristics of an Exercise Dose
F.I.T.T. Principle• Frequency: How often?
• Intensity: How hard?
• Time: How long?
• Type: What type?50
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Art of Exercise Prescription
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• The proper dose of activity is dependent on the desired effect or goals of the individual client
• The dose of exercise needed for achieving better health differs from that needed to achieve peak performance
• Exercise is Medicine focuses on the need for fitness professionals to communicate effectively with medical personnel to realize a client’s goals
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Health Outcomes of Physical Activity: Strong Evidence– lower risk of early death, CHD, stroke,
HBP, adverse blood lipid profile.– lower risk of Type II diabetes and
metabolic syndrome.– lower risk of colon and breast cancer.– prevent unwanted weight gain and
promote weight loss.– improved CRF and muscular strength.– prevention of falls, reduced depression
and improve cognitive function.52
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Health Outcomes of Physical Activity
• Moderate to strong evidence:– better functional health.– reduced abdominal obesity.
• Moderate evidence:– lower risk of hip fracture.– lower risk of lung and endometrial
cancer.– weight maintenance after weight loss.– increased bone density.– improved sleep quality. 53
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Short- and Long-Term Responses to Exercise
• Acute responses: Occur with one or several bouts of exercise, but do not improve further.
• Rapid responses: Benefits occur early, then plateau.
• Linear responses: Gains continue over time.
• Delayed responses: Occur only after several weeks of training.
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Short- and Long-Term Responses to Exercise
• BP and insulin sensitivity are most responsive to exercise.
• Changes to VO2 max and HR are intermediate.
• Serum lipid changes are delayed.
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Short- and Long-Term Responses to Exercise
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Public Health Recommendations
• Minimum of 150 to 300 minutes of moderate-intensity exercise, or 75 to 150 minutes of vigorous-intensity exercise weekly.
• More health-related benefits can be realized by exceeding the minimum recommendations.
• Multiple intermittent bouts daily can accomplish minimum goals.
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Public Health Recommendations
• Resistance training of all major muscle groups should be done on at least 2 nonconsecutive days per week.
• Benefits are gained when a sedentary person becomes active, or when a moderately active person engages in more vigorous activity.
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Guidelines for CRF Programs
• Screen participants.• Encourage regular participation.• Provide a variety of activities.• Program for progression.• warm-up, a cool-down, stretching,
and muscular endurance exercises.• Periodically re-assess your client.
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Formulating the ExRx
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Following FITT PrincipleFrequency
• Moderate intensity (≥5 days per week) • Vigorous intensity (≥3 days per week)
– Gains can be made on <3 day, but intensity would need to significantly increase, and weight-loss goals may become difficult to reach
– For previously sedentary >4 days/wk at vigorous intensity may increase dropout or injury rate
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Formulating the ExRx
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Following FITT PrincipleIntensity
• Moderate intensity (≥5 days per week) • Vigorous intensity (≥3 days per week)
the overall dose should be 500-1000 MET-minutes per week
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Understanding METs
• Intensity of exercise is expressed in metabolic equivalents (METs).
• METs are a ratio of a person’s working metabolic rate to their resting metabolic rate.
• One MET is the energy cost of sitting quietly.
• 1 MET = 3.5 ml·kg-1·min-1
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Understanding METs• Moderate intensity:
– Activity that noticeably elevates HR for more than 10 minutes.
– 3.0-6.0 Mets are the moderate intensity equivalent of 5 to 6 on a 10 point RPE scale.
– Brisk walking is considered moderate intensity.
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Understanding METs• Vigorous intensity:
– Activity that substantially increases breathing and HR.
– > 6 METs is the vigorous activity equivalent of 7 to 8 on a 10-point RPE scale.
– Jogging or running are considered vigorous intensity.
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ExRx: Intensity• Answers the question: “How hard?”• Can be expressed as:
– Percent of VO2 max.– Percent of VO2 reserve (VO2R).– Percent of Heart Rate reserve (HRR).– Percent of max HR.– Rating of perceived exertion (RPE).
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ExRx: Duration• Answers the question: “How many
minutes?”• VO2 max improves with duration.• Optimal duration depends on
intensity.• When the duration of vigorous
exercise exceeds 30 minutes, the risk of injury increases.
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Determining Intensity: Metabolic Load
• Most direct way to determine intensity is percent of VO2 max.
• Optimal range of percent VO2 max for CRF is 60% to 80%.
• Measuring VO2 max is expensive and difficult.
• Target heart rate (THR) is used to approximate training intensity using estimations of VO2 max.
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THR: Direct Method• Maximal GXT:
– intensity is gradually increased– heart rate is linear with metabolic load.– HR is monitored at each stage, and
plotted on a graph against METs.– max value is reached when linear
relationship discontinues.– peak value is reached when the subject
can no longer continue.
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Maximal Heart Rate (MHR)
• Best calculated by GXT results.• GXT is not always possible in the
fitness setting.• Tanaka et. al. refined the max HR
formula to estimate maximal HR.• MHR = 208 - (0.7 x age)
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THR: Indirect Methods• Heart Rate Reserve (HRR)
– difference between resting and maximal heart rate.
– % of HRR = % of VO2R– for average to high levels CRF, % HRR
roughly equals % VO2 max.– HRR Formula:
• [(MHR - RHR) x 60% ]+ RHR = 60 % HRR • [(MHR - RHR) x 80%] + RHR = 80% HRR• values represent range of 60%-80% HRR.
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Training Threshold
• The minimal intensity necessary to elicit a training effect.
• For most of the population, the training threshold is:– 60%-80% of VO2max, HRR and VO2R– 75%-90% HRmax.– 50% - 85% HRR is optimal for CRF
improvement.
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Rating of Perceived Exertion (RPE): Scale of 0-10
Extremely Easy: 0-1 Easy: 2-3 Somewhat Easy: 4-5 Somewhat Hard: 6-7 Hard: 8-9 Extremely Hard: 10
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Program Selection/Type• Part of the FITT Principle
• Depends on client goals, need for supervision, and other personal and environmental variables.
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Programming for Untested and Fit Populations
• As fitness levels improve, absolute exercise intensities must be greater to maintain THR ranges.
• Fit individuals can exercise at >85% VO2max.
• Training for competition requires higher intensities than training for CRF.
• Performance requires increased frequency and duration of training.76
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Guidelines for Health, Fitness and Performance
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Questions/Discussion?