Transcript Exercise Physiology and Fitness

Exercise Physiology & Fitness
CHAPTER 7
McGraw-Hill/Irwin
Copyright © 2012 by The McGraw-Hill Companies, Inc. All rights reserved.
Exercise Physiology & Fitness
2
 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?
Exercise Physiology
3
 The study of the effects of
exercise on the body.
 Body’s responses and
adaptations to different
exercises:


System to subcellular level
Acute (short term) to chronic
(long term) adaptations
 Population served:


Elite performer
People of all ages and abilities
Historical Development
4
 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.
Historical Development
5
 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.
Areas of Study
6
 Effects of various exercises
on various systems of the
body.
 Relationship of energy
metabolism to performance.
 Effects of environmental
factors on performance.
 Effects of individual
differences
 Effectiveness of various
rehabilitation programs.
 Ergogenic aids and exercise.
 Health and therapeutic
effects associated with
exercise.
 Effects of nutrition on
performance.
Specialization
7
EXERCISE PHYSIOLOGY – EMERGING FIELDS OF STUDY
Cardiac
Rehabilitation
Focuses on the assessments of cardiovascular functioning and
on the effectiveness of various exercise programs in preventing
cardiovascular disease and rehabilitating individuals suffering
from the disease.
Exercise
Biochemistry
Examines the effects of exercise at the cellular level, specifically
within the muscle cell.
Exercise
Epidemiology
Studies the relationship between physical activity and mortality.
Pediatric Exercise
Studies the response of the body to exercise during childhood,
including the effects of growth and maturation and how
responses differ between children and adults.
Physical Fitness
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 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.”
Physical Fitness
9
Health Fitness
Performance Fitness

Body composition

Agility

Cardiorespiratory
endurance

Balance

Coordination

Speed

Reaction Time

Power

Flexibility

Muscular endurance

Muscular strength
Physical Activity and Health
10
 Chronic Diseases

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
Physical Inactivity & Health
11
 Inactivity is 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.
Dose-response Debate
12
 What kind of activity?
 How much time spent
in activity?
 At what intensity
should it be performed?
 How often in order to
see benefits?
Consensus Statement
13
 Recommended that adults engage in 150 minutes
of moderate-intensity or 75 minutes of vigorousintensity physical activity per week.
 Recommended that adults engage in muscle-
strengthening exercises on 2 or more days a week
that work all the major muscle groups.
Additional benefits can be derived from
increasing the amount and/or intensity of physial
activity.
Health Benefits
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 Enhanced cardiovascular function, including
reduction of many cardiovascular disease risk
factors.
 Increased 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
Health Benefits
15
 Management of stress.
 Increased socialization through participation in
physical activities.
 Improved overall general motor performance.
 Increased 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.
Energy Production for PA
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 Two ways to produce ATP (adenosine triphosphate)
as energy to perform muscular activity:
 Anaerobic system
 Without
oxygen
 High energy expenditure, short time (6-60 seconds)
 Aerobic
 With
system
oxygen
 Lower rate of energy expenditure, longer period of time
(more than 3 minutes)
Principles of Fitness Training
17
 Principle of Overload
 To gain improvements in health and fitness, an increased
workload must be placed on the body.
 Principle of Specificity
 Training must occur with the specific muscle or body part
the person is attempting to improve.
 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.
Principles of Fitness Training
18
 Principle of 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.
 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.
Planning a Fitness Program
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 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 the
individual
 Program should meet the
goals of the individual.
 FITT Formula
FITT Formula
20
 Frequency
 Number of sessions each week
(i.e., how often).
 Intensity
 Degree of effort put forth
during exercise (i.e., how hard).
 Time
 Duration of activity (i.e., how
long).
 Type
 Mode of exercise being
performed.
Cardiorespiratory Endurance
21
 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.
Cardiorespiratory Endurance
22
FITT Formula
Frequency:
3 to 5 times per week
Intensity:
55% - 90% HRMAX
HRR
Time:
20 - 60 minutes
Type:
Aerobic activities
or 40%
- 85%
Target Heart Rate Zone
23
 HRMAX= 220 bpm – age
 Target zone = 55% to 90%
HRMAX
 Lower threshold target
HR= HRMAX x 55%
 Upper threshold target
HR= HRMAX x 90%
Body Composition
24
 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.
Body Composition
25
 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

Body Mass Index
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 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.
Classifications for BMI
Classification
BMI
Underweight
<18.5 kg/m2
Normal weight
18.5 - 24.9 kg/m2
Overweight
25 - 29.9 kg/m2
Obesity (Class 1)
30 - 34.9 kg/m2
Obesity (Class 2)
35 - 39.9 kg/m2
Extreme Obesity (Class 3)
 40 kg/m2
Energy Balance
27
 Number of calories taken into the body as food
minus number of calories expended.
 Caloric Expenditure:
 Neutral balance


Positive balance


Caloric intake equals expenditure.
More calories consumed than expended.
Negative balance

More calories are expended than consumed.
Body Composition Improvement
28
 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.
Measurement of Body Composition
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 Hydrostatic weighing
 Skinfold measurements
 Body mass index (BMI)
 Dual-energy x-ray
absorptiometry (DXA)
 Bioelectrical impedance
PERCENT BODY FAT NORMS FOR
MEN AND WOMEN
Description
Women
Men
Essential Fat
Athletes
Fitness
Acceptable
Obesity
10-13%
14-20%
21-24%
25-31%
>32%
2-5%
6-13%
14-17%
18-24%
>25%
*Source: ACE Lifestyle & Weight Management Consultant
Manual
Muscular Strength & Endurance
30
 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!
Exercises
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 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
Development of Muscular Strength
and Endurance
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 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
Muscular Strength and Endurance
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FITT Formula
Frequency:
3 days per week
Intensity:
Strength: 6-8 repetitions.
Endurance: 12-20 repetitions.
Time:
1 – 3 sets
Type:
Isotonic or progressive resistance exercises;
can also use isometric and isotonic exercises.
Flexibility
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 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
Improvement of Flexibility
35
 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
Flexibility
36
FITT Formula
Frequency:
2 to 3 days per week (recommended
every day)
Intensity:
Stretch past the normal length until
resistance is felt
Time:
Hold the stretch from 5 – 10 seconds
initially, building to 30 – 45 seconds
Type:
Static or contract-relax techniques
Developing a Fitness Program
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 Medical conditions, such as heart disease, diabetes,
and asthma must be taken into account.
 Consider the participant’s fitness needs and goals.
 Activities selected should allow participants to achieve
the desired fitness goals while maintaining interested
and enjoyment.
 Attention must be directed to educating participants
about the principles of designing a personal exercise
program, assessing their own fitness, and resolving
personal fitness problems.
Effects of Training
38
 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”
Environmental Considerations
39
 Hot and humid
weather




Use extreme caution
Heat cramps, heat
exhaustion, heat stroke
Fluid replacement
Adaptation
 Extreme cold weather



Heat conservation
Hypothermia
Frostbite
Nutrition and Fitness
40
 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.
Nutrition
41
 Food pyramid offers
guidelines for eating a
balanced diet.
 Current U.S. diet is too
high in fat, cholesterol,
sugar, and sodium while
lacking in carbohydrates
and fiber.
 Carefully monitor caloric
intake AND caloric
expenditure.
 Special diets for special
situations.
US Dietary Guidelines - 2005
42
 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
US Dietary Guidelines - 2005
43
 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, trans fatty acids,
and sodium.
 Consume potassium-rich foods.
 Drink alcoholic beverages in moderation.
 Safely prepare foods to avoid illness.
Ergogenic Aids
44
 Work-producing substances or phenomena
believed to increase performance.
 Used to enhance energy use, production, and/or
recovery in quest for improved performance.
 Forms of Ergogenic Aids:
 Mechanical
 Psychological
 Pharmacological
 Physiological
 Nutritional
Caffeine
45
 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.
Carbohydrate Loading
46
 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.
Hydration, Energy & Sports Drinks
47
 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.
Creatine
48
 Used in an effort to increase stores of muscle
phosphocreatine 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.
Anabolic-Androgenic Steroids
49
 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.