Heart rate ABCs - basics - controlling exercise with heart rate monitoring - Brief Article

Better Nutrition, August, 2002 by Edmund R. Burke

Exercise shouldn't be based on the distance traveled, the amount of time involved or the physical workload; it should be controlled by the degree of physical effort as measured by physiological signs, especially pulse rate. The best way to monitor how fast your heart is beating is a heart rate monitor, which usually consists of a strap worn across the chest that sends an electronic signal to a wristwatch-like device that converts the signal into beats per minute.

These monitors enable you to adhere to an exercise program based on heart rate by giving you immediate, continuous and reliable feedback. You are thus less likely to cross the line between healthy exercise for aerobic fitness (a target heart rate of 50 to 90 percent of maximum; see chart) and risky stressful exercise. You will also know if you're not training hard enough to get the full benefits of your efforts, since your workout will be more effective if you maintain a certain pulse rate within your target heart rate zone.

Training below the minimum intensity level, you'll burn mostly fat and won't see much improvement in aerobic capacity. Above the 90-percent level, you'll build up lactic acid; that level of training will make you more susceptible to injury if you're not a highly-conditioned athlete.

understanding heart rate zones

Whatever your objectives--from prevention of chronic disease or cardiac rehabilitation to weight management or winning athletic competitions--you can achieve them most efficiently by working out within certain target heart rate zones. These are represented as a percentage of your maximum heart rate, the fastest your heart should beat.

If your goal is losing weight, exercising at 60 to 70 percent of your maximum heart rate is the minimum zone to effectively burn fat calories. To improve your aerobic endurance and strengthen your heart, you'll need to exercise at 70 to 80 percent of your maximum heart rate.

You can approximate your own training heart-rate zones as follows. First, calculate your maximum heart rate:

220 - Your Age = Maximum Heart Rate

For example, a 30-year-old would have a maximum heart rate of 190. If exercising to gain aerobic fitness, the ideal heart rate for that person would be 70 to 80 percent of the maximum heart rate, or 133 to 152 beats per minute.

There are other methods--including some that are conducted in a laboratory--for determining your maximum heart rate. But you should always consult your physician before beginning any rigorous exercise regime.

% of Maximum   Exercise Zones
Heart Rate

80-100%        Competitive Training
70-80%         Aerobic Training
60-70%         Weight Management
50-60%         Moderate Activity

Note: Table made from bar graph.

Edmund R. Burke, PhD, is the director of the Exercise Science program at the University of Colorado at Colorado Springs and adviser to the United States Olympic cycling team.