Heart rate monitoring is a valuable tool that can help you get more out of your workouts, particularly when combined with interval training. To do this, you need to decide on your personal target heart rates for high-intensity and medium-intensity fitness. Then you monitor your heart rate while you exercise to make sure it stays within the desired range. The result is that your exercise will be tailored for maximum burn.
“Any amount of exercise is good, but if you have a certain goal like losing weight or increasing your cardiovascular fitness, working out at your target heart rate will help,” says Elizabeth Dawes Kim, MD, adult and geriatric psychiatrist at Kaiser Permanente San Francisco. “Think of it like investing; if you’re going to put in the time, you might as well make your exercise work for you..”
The best way to find out your personal target heart rate is to get an evaluation from your doctor, says Kim. To calculate your target heart rate yourself, you need to know your maximum heart rate, which is the highest your heart rate should go during strenuous exercise.
You can estimate your maximum heart rate by subtracting your age from 220. The estimated maximum heart rate for the average 30-year-old, for example, would be 190 beats per minute and for the average 40-year-old it would be 180 beats per minute. But these are just general rules; many factors besides age affect your maximum safe heart rate, such as your overall health and any medications you are taking.
In general, your target heart rate for high-intensity intervals should be about 85 percent of your maximum heart rate. This would mean that if you’re 35 and your maximum heart rate is 185, your high-intensity target heart rate would be about 157 beats per minute. For periods of more moderate exercise, the general advice is to keep your heart rate at 50 to 75 percent of maximum.
“When I’m looking to do build endurance, then I want to keep it in the lower 130 to 140 range, but if I’m looking to do Kubata and other high-intensity interval workouts, then my target rate might be closer to 170,” says Kim.
The American Heart Association has more information on how to determine your target heart rate range, including how to find your resting heart rate.
During the first few weeks of working out, experts suggest aiming for the lower ranger of your target zone (50 percent) and gradually building up to your high-intensity target. After six months or more, you may be able to exercise comfortably at up to 85 percent of your maximum heart rate.
Programming your heart rate monitor with your desired range takes the guesswork out of aerobic exercise, Kim says. “If you’re out walking the dog and it beeps too low, then you know to talk a walk a little faster.” And of course heart rate monitoring can also tell you when you’re pushing yourself too hard. “If your monitor beeps that you’ve gone high, then you know it’s time to rest,” says Kim.