Information for this section taken from: A Report of the Surgeon
General: Physical Activity and Health, U.S. Department of Health
and Human Services, 1996; News Release "Experts Release New
Recommendation to Fight America's Epidemic of Physical Inactivity",
American College of Sports Medicine, July 29, 1993; Guidelines
for Exercise Testing and Prescription, American College of Sports
Medicine, Fifth Edition; K. Weber et al, Exercise Testing in the
Evaluation of Cardiopulmonary Disease, Clinics in Chest Medicine
5, March 1984.
Benefits of exercise
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- Reduces the risk of dying prematurely
- Reduces the risk of dying from heart disease
- Reduces the risk of developing diabetes
- Reduces the risk of developing high blood pressure and helps
reduce blood pressure in people who already have high blood
pressure
- Reduces the risk of developing colon cancer
- Reduces feelings of depression and anxiety
- Helps control weight
- Helps build and maintain healthy bones, muscles and joints
- Helps older adults become stronger and better able to move
about without falling
- Promotes psychological well-being
What does the government say about exercise?
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On July 11, 1996, the U.S. Surgeon General released a report
calling physical inactivity a serious, nationwide problem and
a public health challenge. To rectify the problem, the report
calls for all Americans to do regular, moderate physical activity
on most days of the week.
According to the report, a moderate amount of physical activity
can be achieved in a variety of ways. Keep in mind that the same
amount of activity can be obtained in longer sessions of moderate
activities such as brisk walking as in shorter sessions of strenuous
exercise such as running.
Where do I start?
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The American College of Sports Medicine's guidelines classify
people into three categories to determine who should see their
doctor before starting an exercise program:
1. Apparently healthy individuals can begin moderate exercise
programs without exercise testing or a medical exam. Men 40
years or older and women 50 years or older should have an exercise
test and physical exam before a vigorous exercise program.
2. Individuals at higher risk should have an exercise test
prior to beginning a vigorous exercise program. People should
consider themselves at higher risk if they have two or more
major coronary risk factors including:
- diagnosed hypertension or systolic blood pressure greater
than or equal 160 or diastolic blood pressure greater than or
equal 90 mmHg on at least two separate occasions, or on antihypertensive
medication
- serum cholesterol greater than or equal 6.20 mmol/L (greater
than or equal 240 mg/dl)
- cigarette smoking
- diabetes mellitus
- family history of coronary or other atherosclerotic disease
in parents or siblings prior to age 55
3. People with disease. A thorough medical evaluation is recommended
before starting an exercise program for all people with known
cardiovascular, pulmonary, or metabolic disease.
How do I safely measure my fitness level?
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The most comprehensive assessment of your physical fitness is
a cardiopulmonary exercise test. It measures your heart, lungs,
and circulatory system working together, then simplifies the information
into a several values, including one called VO2max. Essentially,
this value represents your body's ability to deliver oxygen and
remove carbon dioxide, both vital functions of healthy living.
Your doctor will use this information to detect early warning
signs of the airways and lungs, heart, blood vessels, blood, and
cellular metabolism --- even before you may notice symptoms such
as shortness of breath, fatigue, or chest pain.
The test will also measure your heart rate, and your anaerobic
threshold (AT), the point at which your body has reached maximal
aerobic capacity. Before AT occurs, oxygen is effectively delivered
to the working muscles through increased breathing and work can
be continued indefinitely. After AT occurs, lactic acid begins
building up in the muscles, thus creating sore muscles later on.
This measurement is important because AT represents endurance.
To obtain this measurement, the cardiopulmonary exercise test,
sometimes called a gas exchange test, requires you to breathe
through a mouthpiece while taking a standard treadmill stress
test.
Moderate amounts of activity & correlating
VO2max
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VO2max level and correlating Physical
Activity
60-80 Intensive competitive athletics
Marathon running, swimming, cycling, rowing
50-59 Intensive recreational athletics
Mountain climbing, snow skiing, football, motorcycling
40-49 Moderate recreational athletics
Hiking, mowing, dancing, water skiing, stream fishing
25-39 Light recreational athletics
Gardening, golfing, horseback riding, canoeing, tennis, badminton,
level walking at 5 mph
20-24 Recreational activities
Level walking at 4 mph, bicycling at 10 mph, sailing
10-19 Light recreational activities
Fly-fishing, walking at 3.5 mph, bicycling at 8 mph, strolling,
croquet, housework
6-9 Light activities
Driving a car, hobbies done while sitting, standing
What is a good exercise program?
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The best type of exercise to strengthen your heart is aerobic
exercise, the type of activity that involves continuous motion
such as walking, bicycling, jogging, aerobics, and swimming.
They involve activity that requires your heart and lungs to work
harder to supply your cells with more oxygen. This increased workload
improves the condition of your heart and lungs, improving your
overall conditioning and endurance.
The other type of exercise, anaerobic, can be healthy but does
little for your heart. Weight lifting, for example, results in
strong muscles but doesn't challenge your heart and lungs in a
sustained fashion.
How do I know my target heart rate?
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It's best to reach and maintain exercise at a targeted heart
rate level or slightly above it to receive the optimum value from
your exercise activity.
In the past, many people have arrived at an estimated target
heart rate by subtracting their age from 220, then taking 70 percent
of this number to reach so many beats per minute.
However, estimating in this way does not result in a precise,
individualized target heart rate. Recent technological advances
now allow people to have personalized exercise prescriptions which
use your own heart rate based on your current level of fitness
to show how to optimize your fat loss and cardiovascular conditioning
program.
Your personalized exercise prescription will show two exercise
zones: one for optimum fat loss, another for optimum cardiovascular
training. The fat loss zone indicates the heart rate you should
maintain while exercising at a low level intensity such as walking
three to six times a week for more than 45 minutes. The cardiovascular
training zone will indicate the heart rate at which to exercise
at a higher level intensity such as running or cycling three to
six times a week for more than 20 minutes.
