ch11 physical fitness

Chapter 11Physical Fitness

Physical Fitness

• Most people can derive important health benefits by exercising regularly and becoming more physically active.

• Each year, lack of regular physical activity contributes to thousands of American deaths, primarily from heart disease, stroke, and diabetes.

• Physically fit people have the strength, endurance, and flexibility to perform activities of daily living

Physical Fitness

• Healthy adults under age 65 should perform moderate-intensity physical activity for 150 minutes per week (minimum)

• Moderate to vigorous activities should be performed in bouts that last at least 10 minutes, preferably spread throughout the week.

• In 2010, 1/3 of American adults did not exercise during their leisure time.

Principles of Physical Fitness

The Body in Motion– Physical movement involves the functioning of

the muscular and skeletal system• often referred to as musculoskeletal

system– Skeletal muscles provide shape, support, and

movement.– Skeletal muscle made up of muscle fibers.

Principles of Physical Fitness

The Body in Motion

– Tendons connect muscle to bone– Joints are where bones come together– Ligaments connect bone to bone

The Circulatory and Respiratory Systems

• Heart and lung function is interrelated• The heart pumps blood to the lungs• Oxygenated blood returns to the heart where it

is pumped to rest of body• Oxygen leaves blood and enters cells• Waste products such as carbon dioxide leave

cells and enter blood• Blood carries waste products to kidneys and

back to the heart

•Resting heart rate decreases 15 to 20 beats per minute

•Stroke volume increases

•Cardiac output increases during maximal effort

Circulatory System Principles

Principles of Physical Fitness

Physical Activity vs Exercise

Physical Activity- mowing, walking, gardening

Exercise- planned and performed to improve or maintain physical condition

RECOMMENDATION FOR EXERCISE

Every U.S. adult should accumulate 30 minutes or more of moderate intense physical activity on most and

preferably all days of the week. American College of Sports Medicine and Centers for Disease Control

Benefits of Exercise

• Reduces risk of chronic diseases.– Heart disease, certain cancers, type 2 diabetes,

hypertension, and osteoporosis• Reduces risk of obesity.• Improves immune system.• Improves and maintains muscle strength and joint

function.• Improves balance.• Reduces risk of premature death.

• Reduces symptoms of anxiety and depression.• Fosters improvement in mood and sense of well-

being.• Can improve quality of sleep.• Stimulates release of endorphins.• May relieve stress.

The Health-Related Components of Physical

Fitness

Cardiorespiratory fitnessMuscular strength

Muscular enduranceFlexibility

Body composition

• Intense physical activity requires more oxygen to support the work of skeletal muscles.

• Individuals with high degrees of cardiorespiratory fitness, or endurance, can perform intense physical activity longer without becoming fatigued.

• Cardiorespiratory fitness can be developed through aerobic activities (e.g., running, swimming, rope skipping).

Cardiorespiratory Fitness

Assessing Cardiorespiratory Fitness

To raise heart rates sufficiently to enhance cardiorespiratory fitness, the

physical activity should raise heart rates to within the target zone, generally 55% to 90% of one’s

maximum heart rate

Muscular Strength and Endurance

Muscular strength: ability of muscles to apply maximum force against an object that is resisting that forceMuscular endurance: ability to contract muscles repeatedly without becoming fatigued easily

Training Effect: an increase in size and strength of the muscle

Training Effect

Hypertrophy: a condition in which muscles become larger and stronger

Atrophy: when muscles lose size and strength from lack of use

Lifting

Repetition: the completion of a single movement (exercise) that overloads a particular muscle groupSet: involves performing the same exercise movement a number of times

Strength - 6 to 12 repsEndurance - 15+ reps

Types of Contractions

• Isotonic: Muscle length changes –Concentric- shortens–Eccentric - lengthens

• Isometric: muscle doesn’t change length

Flexibility• the ability to move a joint through its normal

(entire) range of motion

Static stretching:slowly and fully extending muscles and joints within natural range of motion (book says 15-30 seconds)

Ballistic stretching: (rapid bouncing)not recommended for general fitness training

Body Composition• The percentages of body weight contributed by

lean tissue (LBM) and fat• Some fat is essential to good health (about 4% in

men and 10% in women)• Spot exercising does not reduce fat in the

exercised region• Exercising can increase metabolic rate• Engaging in moderate to vigorous–intensity

aerobic activity for about 60 minutes, nearly every day, while not exceeding daily calorie needs, “burns” body fat

Athletic Performance

Speed—rate of movementPower—ability to concentrate forceCoordination—ability to perform a series of movements in a continuous mannerAgility—ability to make quick precise movementsBalance—ability to maintain poised upright body positionReaction time—time needed to adjust body position to a changing environment

Sports Related Components of Physical Fitness

Diet and Performance• Drink adequate amounts of water and choose a

well-balanced diet composed of a variety of foods (same size does not fit all-IIFYM)

• Eating more protein than needed does not result in bigger muscles (not true)

• High protein diets may cause dehydration and accelerate the loss of calcium from bones

• Carbohydrate loading can help certain athletes

Ergogenic Aids

• There are a variety of products that supposedly enhance physical development or performance.• Dietary supplements, drugs, and mechanical

devices• Some are beneficial and/or harmless.• Others are dangerous or illegal.

• Anabolic steroids

Anabolic Steroids

• Synthetic and natural substances chemically related to testosterone and have muscle-building properties.

• Often illegally obtained and abused by athletes who want to enhance muscle development and physical performance.

• Give individuals unfair competitive advantage over other athletes.

Steroids: Side Effects

Men:• Premature balding• Severe acne• Sleep disturbance• Increased aggression• Testicle shrinkage• Increased blood pressure and increased

risk of developing heart and kidney disease, certain cancers, and liver tumors

Steroids: Side EffectsWomen:

• Severe acne• Increased body hair, including facial hair• Scalp hair loss• Menstrual irregularities

Exercising for Health

F.I.T.T. Principle

F- frequency (number of days per week)I - intensity (how hard you train)T- time (how long you train)T- type (what you choose to do)

A Well Planned Workout

1. Warm up: low intensity activity for 5 minutes2. Engage in aerobic activity for 30 minutes3. Warm down with less intense activity for 5 minutes4. Stretch: 5 minutes

Danger Signs

Stop and consult a physician if you experience:• Irregular heartbeat, sensation that heart is

pounding in throat, or fluttering sensation in chest

• Pain or pressure in the chest, throat, or arms• Shortness of breath • Dizziness• Sudden loss of coordination• Cold sweating• Fainting

Preventing and Managing Exercise Injuries

Strains and SprainsNo clear clinical definitions exists• Strain generally refers to damage that a muscle or

tendon sustains when overextended rapidly.• Sprain usually refers to a damaged ligament

–usually more serious

Preventing and Managing Exercise Injuries

Strains and SprainsRICE—effective for treating strains and sprains• Rest• Ice• Compression• Elevation

Consult a physician if injured area does not improve in 2 days, or if pain worsens.

Preventing and Managing Exercise Injuries

Dislocation• A joint becoming displaced by force• Joints are susceptible to dislocation during

certain strenuous physical activities

Heat Related Issues

Dehydration: extreme loss of body waterHyperthermia: higher than normal body temperature

• Heat cramps• Heat exhaustion• Heatstroke

Heat Related IssuesTo prevent dehydration and hyperthermia:

• Avoid physical exertion outdoors during hottest time of the day.

• Drink enough fluids to replace that which is lost through sweat.

• Wear light-colored, loose-fitting clothing when exercising in warm conditions.

• Consider reducing the intensity and duration of activity when weather is hot and humid.

• Avoid alcoholic beverages.

Cold Related IssuesFrostbite

• Ice crystals form in the deeper tissues of skin when exposed to extreme cold

• Causes damage to tissuesHypothermia

• Body’s core temperature drops below 95°F–Shivering–Tiredness–Poor judgment–Disorientation–Loss of consciousness

Cold Related Issues

Preventing Hypothermia• When in cold temperatures, wear:

–Layers of warm dry clothing–A hat that can be pulled down over ears–Scarf–Gloves or mittens–Thick socks

Developing a Personal Fitness Program

• Determine your needs, interests, and limitations.• Set general fitness goals.• Choose activities that you enjoy.• Incorporates fitness session into your routine.

Across the Life Span

• Physical activities adopted in childhood are likely to be practiced for a lifetime

• Healthy, physically fit women can generally continue engaging in mild- to moderate- intensity exercise during pregnancy• Pregnant women who perform strenuous

regular exercise can increase their risk of having low-birth-weight babies

• Pregnant women should discuss exercise plans with their physicians

Across the Life Span• Most Americans become less active as they age.• However, it is important for people to continue

exercising.• Light regular physical activity can help:

• Reduce risk of heart disease, colon cancer, diabetes, obesity, and hypertension.

• Maintain or improve joint flexibility and muscle strength and endurance.

• Improve mood.• Increase ability to live independently.