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chapter
19
Prescription of
Exercise for
Health and
Fitness
Learning Objectives
• Understand the importance of a physically active
lifestyle for health promotion and disease prevention
• Discover the importance of obtaining medical clearance
before prescribing an exercise program and understand
what constitutes the basic components of medical
clearance
• Learn the principles of exercise testing and the exercise
electrocardiogram
(continued)
Learning Objectives (continued)
• Review the components of a sound exercise program
– Exercise prescription: type of exercise, frequency,
duration, and intensity
– Methods of monitoring exercise intensity
– Components of an exercise program: warm-up and
cool-down; endurance, flexibility, and resistance
training; and recreational activities
• Discover how to become more physically active and
gain the benefits of regular exercise
Physical Activity Statistics
• Nearly 40% of the U.S. population >18 years of age
report no leisure-time physical activity of light,
moderate, or vigorous intensity for at least 10 min
• Only 22% report engaging in vigorous physical activity
sufficient to promote the development and maintenance
of aerobic fitness (3 or more days/week, 20 or more
minutes)
• Only 20% report doing physical activity specifically
designed to strengthen muscles at least twice a week
The Beginning of the
Fitness Revolution
Dr. Kenneth H. Cooper
Surgeon General’s
Recommendations
• People of all ages, male and female, benefit from
regular physical activity
• At least 30 minutes of moderate to intense exercise on
most days of the week can improve health
• Additional health benefits are gained through greater
amounts of physical activity
°
Dr. Per-Olof Astrand,
Eminent
Swedish Physician and Physiologist
Purpose of Medical Clearance
• Helps identify potential risk factors
• Helps to develop an appropriate exercise prescription
• Helps motivate individuals to know their current blood
pressure, body fat, and blood lipid concentrations
• Provides a baseline to compare changes in health
• Provides an opportunity to check for early stages of
disease
Who Must Receive
Medical Clearance
• Men over 45
• Women over 55
• Anyone who has risk factors of CAD or
cardiopulmonary disease
Graded Exercise Testing
• Obtained while exercising on a treadmill or cycle
ergometer
• Rate of work is generally increased every 1-3 minutes
until maximal work rate is achieved
• Exercise electrocardiogram is obtained to monitor heart
rhythm and electrical conduction abnormalities and to
potentially identify existing coronary artery disease
• Exercise blood pressure is monitored
Obtaining an Exercise ECG
© Human Kinetics
Exercise ECG: (a) Normal ECG and (b)
an ECG With ST-Segment Depression
a
b
Major Signs and Symptoms Suggestive
of Cardiovascular, Pulmonary,
or Metabolic Disease
• Pain or discomfort in the chest, neck, jaw, arms, or other
areas that may be ischemic in nature
• Shortness of breath at rest or with mild exertion
• Dizziness or syncope
• Paroxysmal nocturnal dyspnea
• Ankle edema
• Palpitations or tachycardia
• Intermittent claudication
• Known heart murmur
• Unusual fatigue or shortness of breath with usual
activities
Graded Exercise Testing
• Sensitivity: exercise test’s ability to correctly identify
individuals who have the disease in question
• Specificity: test’s ability to correctly identify individuals
who do not have the disease in question
• Predictive value of an abnormal exercise test:
accuracy with which abnormal test results reflect the
presence of the disease
Medical Evaluation and Clearance
Key Points
• Before beginning an exercise program, men over 45,
women over 55, and anyone who is considered to be at
a high risk for CAD should have a comprehensive
medical evaluation
• ACSM guidelines should be followed for each phase of
the evaluation
• Exercise ECGs should be conducted for high-risk
individuals to detect undiagnosed CAD and other
cardiac abnormalities
Components of
Exercise Prescription
Mode or type of exercise—usually one or more
cardiovascular endurance activities
Frequency—3 to 5 days per week (or more)
Duration—20 to 30 minutes is optimal
.
Intensity—generally at least 50-60% VO2max, although
this varies individually, and health benefits can occur at
lower intensities
Minimum Threshold
• A minimal threshold for frequency, duration, and
intensity must be reached before any aerobic benefits
are obtained
• Threshold varies individually
Training Heart Rate: Linear Relationship
.
Between Heart Rate and VO2
Karvonen Method
• Maximal heart rate reserve = HRmax − HRrest
• Target heart rate (THR) is calculated:
THR75% = HRrest + 0.75 (HRmax − HRrest)
• Training heart rate ranges can be determined
Metabolic Equivalent (MET)
• Based on the value of resting metabolic rate
3.5 ml ∙ kg−1 ∙ min−1 = 1.0 MET
• Useful for a training guideline, but it fails to account for
environmental conditions, and it does not allow for
changes in physical conditioning
(continued)
(continued)
The Borg Ratings of Perceived
Exertion Scale
Reprinted, by permission, from G. Borg, Borg's perceived exertion and pain scales (Champaign, IL: Human Kinetics), 47.
The Exercise Program
•
•
•
•
•
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Warm-up and stretching
Endurance exercise
Cool-down and stretching
Flexibility training
Resistance training
Recreational activities
Warming Up and Cooling Down
• Involves low-intensity exercise and stretching
• Warm-up prepares the cardiovascular, respiratory, and
muscle systems for more intense exercise
• Cool-down prevents blood from pooling in the
extremities and muscle soreness
Starting a Resistance
Training Program
• Begin with a weight that is one-half of the person’s 1RM
• This is the proper weight if the person can lift it ~10
times
• After reaching 15 reps, progress to a heavier weight
• For weight control: 2-3 sets of each lift per day, 2-3 times
per week
(continued)
(continued)
Recreational Activities
• Important part of any comprehensive exercise program
• Offer enjoyment and relaxation
• Can also improve health and fitness
Exercise and Rehabilitation
of People With Diseases
•
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Cancer
Obesity
Diabetes
Renal disease
Osteoporosis
Arthritis
Chronic fatigue syndrome
Fibromyalgia
Cystic fibrosis