Chapter 15 Staying Physically Active: A Way of Life
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can calculate your maximum heart rate
using the following formula:
220 – your age = maximum heart rate
A 16-year-old using this formula
would calculate his or her maximum
heart rate to be 204 beats per minute
(220 – 16 = 204). A 50-year-old would
calculate his or her maximum heart
rate to be just 170 beats per minute
(220 – 50 = 170).
Exercising Your Heart
The heart is a strong muscle. Like
your other muscles, your heart needs
exercise. Measuring your heart rate
can help you see if you are giving your
heart enough exercise.
For good exercise, your heart
needs to beat faster than its resting rate.
However, it should not beat so fast that it
is unsafe. You should never try to reach
your maximum heart rate. Instead, you
should try to exercise within a safe target
heart rate zone. This is the range of
heartbeats per minute at which the heart
muscle receives the best workout. Your
target heart rate zone is 60 to 90 percent
of your maximum heart rate. A 16-year-
old would calculate target heart rate zone
as follows:
Maximum heart rate:
220 – 16 = 204 beats per minute
204 × 0.6 = 122 beats per minute
204 × 0.9 = 184 beats per minute
Target heart rate zone:
122 to 184 beats per minute
When you begin an exercise
program, count your heart rate frequently
during your workouts. This will help
you decide whether you are pushing
yourself too little or too much. Your
initial goal should be to keep your heart
rate at the low end of your target zone.
As your fi tness improves, you should
be keeping your heart rate closer to the
high end of your target zone, 15-12.
Keys to a
Successful
Exercise Program
Beginning an exercise program
can be hard for some people. You need
to feel sure rewards will follow. Talk
with people who exercise regularly. Ask
them what benefi ts they have noticed
as a result of being physically active.
Their answers may inspire you to begin
an exercise program that includes more
than just daily lifestyle activities.
Extend
Your Knowledge
Facts About Resting Heart Rate
The American Heart Association reports that the
best time to measure your resting heart rate is in the
morning, after a good night’s sleep, and before you
get out of bed. The heart beats about 60 to 80 times
a minute when at rest. Resting heart rate usually rises
slightly with age. It is usually lower for physically fit
people, often lower than 65 beats per minute. Resting
heart rate is used to determine one’s training target heart
rate. The heart rate adapts to changes in the body’s
need for oxygen, such as during exercise or sleep.
Extend
Your Knowledge
How Does Your Heart Rate?
Measure your resting heart rate after sitting for 30
minutes or more. Record your resting heart rate. After
taking a leisurely walk for 10 minutes, measure and
record your heart rate. Measure and record your heart
rate after a brisk 10-minute-walk. Were the results
what you expected? Determine your resting heart rate
fitness rating using guidelines provided in this chapter.
(If your results are consistently high, you should
consult your health-care provider.)