24

Heart-Rate Monitoring

Consistently performing aerobic exercise is a key to developing
the aerobic system. You can walk, jog, run, bike, swim, dance or do
almost anything aerobically. Unfortunately, these activities can also be
anaerobic. You can take the guesswork out of your workout and be
assured you’re truly aerobic by understanding your heart rate.
Throughout this book I’ve talked about fat- and sugar-burning. I
previously discussed measuring oxygen and carbon dioxide during
exercise to determine the respiratory quotient (RQ), which indicates
how much fat and sugar a person is burning. As accurate as this may
be, laboratory testing for RQ is also very impractical for the average
person. The best option — the most useful and least expensive way —
to make sure your exercise is training the aerobic system is with a
heart-rate monitor.
I began using heart rate monitors soon after entering private
practice in the late 1970s. Today, many people use heart monitors
while running, walking, dancing or riding a bike. As you attain high-
er levels of exercise intensity, your heart rate increases, and less fat
and more sugar is burned for energy. Most importantly, the level of
exercise intensity will dictate how your body reacts to that exercise
session during the next 24 hours. Higher levels of intensity, and high-
er heart rates, train your body to burn more sugar and less fat, while
easier exercise and lower heart rates do just the opposite. You can
monitor this with your heart rate.
There are two ways to check your heart rate, by hand or using a
monitor. Trying to obtain your heart rate by stopping to take your
pulse is often very inaccurate. If you are just one or two beats off in a
six-second count, that’s a difference of 10 to 20 beats per minute!
When you stop to take a pulse, your heart rate decreases rapidly. In
six seconds, the rate may drop by 10, 15 or 20 beats per minute. In