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©2009 McGraw-Hill Higher Education. All rights reserved.
Exercise Physiology & Fitness
Chapter 7
©2009 McGraw-Hill Higher Education. All rights reserved.
Exercise Physiology & Fitness
What is exercise physiology? What is the role of physical
activity and exercise in achieving physical fitness and health?
How do you use the FITT formula to design a fitness program?
What are the contributors and deterrents to fitness?
©2009 McGraw-Hill Higher Education. All rights reserved.
Exercise Physiology
The study of the effects of exercise on the body.
Body’s responses and adaptations to exercises System to subcellular level Acute (short term) to chronic (long term) adaptations
Population served Elite performer People of all ages and abilities
©2009 McGraw-Hill Higher Education. All rights reserved.
Historical Development Late 1800s - the use of anthropometry to
measure changes in students’ development after training programs.
Early 1900s – McKenzie ~ Investigating effects of exercise on various systems of the body and the idea of preventative medicine
After WWII - increased interest in fitness as a result of youth fitness tests and the results of the physicals of men in the military.
1968 – Dr. Kenneth H. Cooper promotes aerobic exercise and its contribution to health; publishes Aerobics
©2009 McGraw-Hill Higher Education. All rights reserved.
Historical Development
1970s: APS recognized exercise physiology as a specialized area of physiology.
1974: ACSM: Guidelines for Graded Exercise Testing and Prescription
1980s and 1990s: Increased understanding of the relationship between physical activity and health. 1996:Surgeon General’s Report Physical Activity &
Health 2000: 1st certification exams for Clinical Exercise
Physiologists
©2009 McGraw-Hill Higher Education. All rights reserved.
Areas of Study
Effects of various exercises on various systems of the body
Relationship of energy metabolism to performance
Effectiveness of training programs
Effects of environmental factors on performance
Identification of factors that limit performance
Effectiveness of various rehabilitation programs
Ergogenic aids and exercise
Health and therapeutic effects associated with exercise
Effects of nutrition on performance
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Specialization
Cardiac rehabilitation Assessment of cardiovascular functioning Prevention of cardiovascular disease Rehabilitation of individuals with the disease
Exercise biochemistry Effects of exercise at the cellular level Exercise epidemiology: Relationship between
physical activity and mortality Pediatric exercise science:Scientific study of
the response of the body to exercise during childhood and maturation.
©2009 McGraw-Hill Higher Education. All rights reserved.
Physical Fitness
Ability of the body’s systems to function efficiently and effectively.
Individuals who are “physically fit” have the ability to: “carry out daily tasks with vigor and
alertness, without undue fatigue, and with ample energy to enjoy leisure-time pursuits and to meet unforeseen emergencies.”
©2009 McGraw-Hill Higher Education. All rights reserved.
Physical Fitness
Health fitness Body composition Cardiorespiratory
endurance Flexibility Muscular
endurance Muscular strength
Performance fitness Agility Balance Coordination Endurance Flexibility Muscular
endurance Muscular strength
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Physical Activity and Health
Chronic disease – major threat to health today
Hypokinetic diseases Diseases caused by insufficient physical
activity, often in conjunction with inappropriate dietary practices.
Coronary heart disease, hypertension, osteoporosis, non-insulin diabetes, chronic back pain, and obesity
©2009 McGraw-Hill Higher Education. All rights reserved.
Physical Inactivity & Health
Inactivity a risk factor for several diseases
Individuals who lead a sedentary lifestyle have increased risk of morbidity and mortality. Inactive individuals have almost twice
the risk of CHD as those who are active The degree of risk is similar to
cigarette smoking, hypertension, and obesity.
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Dose-response Debate
What kind of activity? How much time spent in activity? At what intensity should it be
performed? How often in order to see benefits?
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Consensus Statement There is an inverse and generally linear
relationship for rates of all-cause mortality, total CVD, and CHD incidence and mortality and for the incidence of type 2 diabetes.
Accumulation of at least 30 minutes of moderate-intensity PA on most days of the week is associated with a significant 20%-30% reduction in all-cause mortality.
Additional benefits can be derived from increasing the amount and/or intensity of physial activity.
©2009 McGraw-Hill Higher Education. All rights reserved.
Health Benefits
Enhanced cardiovascular function Reduction of many cardiovascular disease
risk factors Increase ability to perform tasks of daily
living Reduced risk of muscle and joint injury Improved work performance Improved physical appearance, self-image,
and sound mental health Reduction of susceptibility to depression
and anxiety
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Health Benefits Management of stress Enhancement of self-concept and esteem Socialization through participation in
physical activities Improved overall general motor
performance Energy Resistance to fatigue Mitigate the debilitating effects of old-
age or retain a more desirable level of health for a longer period of time
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Energy Production for PA
Use of ATP as energy to perform muscular activity. Two ways to produce ATP:
Anaerobic system Without oxygen High energy expenditure, short time (6-60
seconds) Aerobic system
With oxygen Lower rate of energy expenditure, longer period
of time (more than 3 minutes)
©2009 McGraw-Hill Higher Education. All rights reserved.
Principles of Fitness Training
Principle of overload To improve improvements in health and fitness,
an increased workload must be placed on the body.
Principle of specificity Design program to reflect specific goals.
Principle of progression Overload should be applied gradually, and
steadily increased as the body adapts. Principle of diminishing returns
As fitness increases, gains achieved become less and less as individuals approach limits of adaptability
©2009 McGraw-Hill Higher Education. All rights reserved.
Principles of Fitness Training
Principle of variation Variation helps maintain individuals’ interest
and provides a change of pace while continuing to make progress toward desired goals
Principle of reversibility “Use it or lose it” – inactivity leads to gradual
erosion of benefits achieved Cardiovascular gains can disappear
within 5-10 weeks of inactivity Some strength gains persist for 6 months
to 1 year after cessation of training
©2009 McGraw-Hill Higher Education. All rights reserved.
Principles of Fitness Training
Principle of individuality Individuals respond differently to
exercise and will vary in their rate of improvement and levels of achievement.
Principle of recovery Rest allows the body to recover and
adapt to the changes placed on it Principles of safety
Safety is paramount
©2009 McGraw-Hill Higher Education. All rights reserved.
Principles of Fitness Training
Include warm-up and cool down as part of the training program Helps prevent injury and prepares body
for exercise as well as returns it to a normal state.
Consider behavioral factors Motivation of individual to adhere to
fitness program Promote adherence through strategies as
goal-setting and enhancing self-efficacy
©2009 McGraw-Hill Higher Education. All rights reserved.
Planning a Fitness Program
Threshold of training Minimal level of exercise needed to achieve
desired benefits.
Target zone Defines the upper limits of training and the
optimal level of exercise.
Needs and goals of individual Program should meet the goals of the individual
FITT Formula
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FITT formula
Frequency Number of sessions each week
Intensity Degree of effort put forth during
exercise. Time
Duration of activity Type
Mode of exercise being performed
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Cardiorespiratory Endurance
Body’s ability to deliver oxygen effectively to the working muscles to perform physical activity.
Most important component of health fitness.
Helps prevent hypokinetic disease. Concerned with the aerobic
efficiency of the body.
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Cardiorespiratory Endurance
Frequency: 3 to 5 times per week Intensity: 55% - 90% HRMAX
40% - 85% HRR Time: 20 - 60 minutes Type: Aerobic activities
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Target Zone
HRMAX= 220 bpm - age Target zone = 55% to 90% HRMAX
Lower threshold target HR= HRMAX x 55%
Upper threshold target HR= HRMAX x 90%
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Body Composition
Percentage of body weight composed of fat as compared with fat-free or lean tissue.
Obesity is associated with numerous health problems and earlier mortality.
Determination of the cause of obesity is important.
©2009 McGraw-Hill Higher Education. All rights reserved.
Body Composition
Body composition is influenced by nutrition and physical activity.
Energy balance is important to achieving a favorable body composition.
Energy expenditure through: basal metabolism (maintenance of essential life
functions) work (including exercise) excretion of body wastes
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Body Mass Index
Estimated – Weight in pounds
X 703 divided by height in inches squared
Often used in large scale surveys because of ease of collecting large amounts of data
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Energy Balance
Number of calories taken into the body as food minus number of calories expended
Caloric expenditure Neutral balance
Caloric intake equals expenditure. Positive balance
More calories consumed than expended. Negative balance
More calories are expended than consumed.
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Body Composition Improvement
Decreasing percentage of fat Decrease caloric intake through diet. Increase caloric expenditure through physical
activity and exercise. Moderate decrease in caloric intake and
moderate increase in caloric expenditure. Follow sound practices
Obsession with weight loss, in conjunction with many other factors, may contribute to the development of an eating disorder.
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Measurement of Body Composition
Hydrostatic weighing Skinfold measurements Body mass index (BMI) Dual-energy x-ray absorptiometry
(DXA) Bioelectrical impedance
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Muscular Strength & Endurance
Muscular strength is the ability of a muscle or a muscle group to exert a single force against a resistance.
Muscular endurance is the ability of a muscle or muscle group to exert force repeatedly or over a period of time.
Maintenance of proper posture; protect joints. Production of power to enhance performance. Use it of lose it!
©2009 McGraw-Hill Higher Education. All rights reserved.
Exercises
Isometric exercises Muscle exerts force against an immovable object. Static contraction
Isotonic exercises Force is generated while the muscle is changing
in length. Concentric and Eccentric contractions
Isokinetic exercises Contractions are performed at a constant velocity
©2009 McGraw-Hill Higher Education. All rights reserved.
Development of Muscular Strength and Endurance
Principle of Overload is critical. Repetition - performance of a movement
through the full range of motion. Set - number of repetitions performed
without rest. Strength
Low number of repetitions with a heavy resistance.
Endurance High number of repetitions with a low resistance
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Flexibility
Maximum range of motion possible at a joint Joint specific: better range of motion in
some joints than in others. Can prevent muscle injuries & low-back pain Decreased flexibility can be caused by:
Sedentary lifestyle (lack of use of muscles) Age High amounts of body fat Stress
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Improvement of Flexibility
Ballistic stretching Momentum generated from repeated bouncing to
stretch. (Not recommended) Static stretching
Slowly moving into a stretching position and holding for a certain period of time (10-30 seconds; 5 times).
Contract-relax technique Relaxing of the muscle to be stretched by
contracting the opposite muscle (hamstrings/quadriceps)
Measurement of flexibility - goniometer
©2009 McGraw-Hill Higher Education. All rights reserved.
Conducting Fitness Programs
Provide for cognitive and affective goals as well as physical activity.
Make fitness enjoyable. Establish goals and a plan of action to
attain them. Monitor progress. Provide for maintenance of fitness. Fitness requires personal commitment.
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Effects of Training
Lower oxygen consumption Lower pulse rate Larger stroke volume Lower rise in blood pressure Slower respiration rate Lower rate of lactic acid
formation Faster return to “normal”
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Effects of Training
Greater cardiorespiratory efficiency. Greater endurance. More “work” can be performed at less
cost. Improvement in fitness components. Coordination and timing of
movements are better.
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Physical Activity & Health
Adults - 30 minutes of physical activity equal to brisk walking on most, preferably all, days of the week.
Children – 60 minutes of physical activity on most, preferably all, days of the week
Activity of greater intensity will yield greater health benefits.
Strength-developing activities at least twice a week.
Physical activity as an integral part of one’s lifestyle.
©2009 McGraw-Hill Higher Education. All rights reserved.
Environmental Considerations
Hot and humid weather Use extreme caution Heat cramps, heat exhaustion, heat stroke Fluid replacement Adaptation
Extreme cold weather Heat conservation Hypothermia Frostbite
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Nutrition and Fitness
Nutrients carbohydrates fats proteins vitamins minerals water
Maintaining water balance is important.
A well-balanced diet is necessary to obtain all the nutrients required by the body.
©2009 McGraw-Hill Higher Education. All rights reserved.
Nutrition
Food pyramid offers guidelines for eating a balanced diet.
Current U.S. diet is too high in fat, cholesterol, sugar, and sodium and lacking in carbohydrates and fiber.
Carefully monitor caloric intake AND caloric expenditure.
Special diets for special situations.
©2009 McGraw-Hill Higher Education. All rights reserved.
US Dietary Guidelines - 2005
Consume adequate nutrients within caloric needs
Maintain body weight within a healthy range
Engage in regular physical activity (PA) 30 minutes of moderate-intensity PA/day to
reduce risk of chronic disease Greater health benefits can be accrued from
engaging in PA for a longer time and/or at a greater level of intensity
©2009 McGraw-Hill Higher Education. All rights reserved.
US Dietary Guidelines - 2005
Consume a sufficient amount and variety of fruits and vegetables
Consume at least half of your grains from whole grains
Consume 3 cups/day of fat-free or low-fat milk or equivalent mild products
Limit consumption of saturated fatty acids and trans fatty acids
Limit consumption of sodium Consume potassium-rich foods Drink alcoholic beverages in moderation Safely prepare foods to avoid illness
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Ergogenic Aids Work-producing substances or
phenomena believed to increase performance
Used to enhance energy use, production, and/or recovery in quest for improved performance
Forms Mechanical Psychological Pharmacological Physiological Nutritional
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Caffeine Stimulant, restricted by IOC – standard up to
6 to 8 cups of coffee Enhances muscle tension development,
increased alertness, decreased perception of fatigue, increased endurance performance
Effect depends on dosage and amount of caffeine athlete typically consumes
Side effects – very rapid heart rate, diuresis, insomnia, nervousness, diarrhea, anxiety
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Carbohydrate Leading Used in endurance events lasting 60 to
90 minutes or longer in order to maintain pace and delay fatigue
Change training regimen and modify diet to eat more complex carbohydrates than normal in order to store additional glycogen in muscles and liver to provide extra energy
Pre-event meal – 1 to 5 grams of carbohydrate per kilogram of body weight 1 to 4 hours prior to event
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Hydration, Energy & Sports Drinks
Proper hydration is important for safety reasons and to improve performance.
Fluid replacement during exercise is associated with lower heart rate, body core temperature, and levels of perceived exertion.
Water – 4-6 ounces for every 15-20 minutes of exercise
Sports and/or energy drinks – add fluid as well as replace lost electrolytes and supply additional carbohydrates
©2009 McGraw-Hill Higher Education. All rights reserved.
Creatine Used in an effort to increase stores of muscle
phosophocreatine and have more fuel available to support short, high intensity activity
Used in conjunction with a resistance training program to maximize muscle strength and increase fat-free mass
ACSM – creatine supplementation enhances exercise performance in events involving short periods of extremely powerful activity, especially during repeated efforts.
©2009 McGraw-Hill Higher Education. All rights reserved.
Anabolic-Androgenic Steroids
Synthetic forms of male hormone testosterone – testosterone secreted by testes is responsible for the development of masculine characteristics and promotion of growth of tissue, muscle mass, weight, and bone growth
Taken orally or injected in 10 to 100 times the recommended therapeutic dosage
Banned by IOC and some sport organizations Serious side effects, some irreversible,
associated with chronic use including increased risk of heart disease, liver tumors, cancer, hypertension, mood swings, aggressive behavior.