Target Heart Rate: How to Calculate It

You finally concluded that you need to get into better physical shape and you are motivated and have even started and exercise program. You are now trying to figure out what your target heart rate should be to exercise in your aerobic zone. There’s a couple different ways to determine your target heart rate and a couple of things to keep in mind.

First Things First

How high you can get your heart rate during exercise is a good approximation of how much oxygen you can move through your body.  And, how much oxygen you can move largely determines how fit you are aerobically. The more oxygen you can move the more fit you are, and generally more healthy you are.

Higher levels of aerobic fitness are also associated with lower all-cause and cardiovascular mortality. In fact, you can obtain a better risk reduction in heart disease by increasing your aerobic fitness than you can from lowering your cholesterol, quit smoking, and keeping your blood pressure and blood sugar under control.

In other words, high aerobic fitness is more beneficial than modifying those other risk factors of heart disease. Keep that in mind. Exercise is free and has few side effects unlike medications.

Predicted Maximum Target Heart Rate

One thing you will need to determine is your predicted maximum heart rate.  To take the guessing out you can have this actually determined through an exercise treadmill test or bicycle ergometer test. But, short of that there are a couple of formulas you can use.

The most popular is to subtract your age from 220. This is the easiest way, but tends to slightly overestimate maximum heart rate in the young and slightly underestimate in the older crowd.  A more accurate method is to multiply your age by 0.7 and subtract that number from 208.  So if you’re 50 your predicted maximum heart rate would be 208 minus (50 times 0.7) which equals 173. Once you determined your predicted maximum heart rate you then determine the upper and lower intensity/heart rates to keep yourself in the aerobic zone.

Exercising in the Aerobic Zone

The aerobic zone is defined by an upper and lower heart rate. The minimum level of intensity or lower heart rate is referred to as the aerobic training threshold.  This sets the low end of your target heart rate zone. This is the level of intensity you must reach in order to see improvement in your aerobic fitness.

The upper level of intensity or upper heart rate is called the anaerobic threshold. Exercising above this number no longer stresses or loads the aerobic system and instead loads the anaerobic system.  There is nothing wrong with exercising in the anaerobic zone, and in fact, you should spend some time doing that, but that’s another article.

To get into the anaerobic zone you have to pass through the aerobic zone – so there is aerobic benefit by doing high intensity training which we strongly recommend if you do not have heart issues.

Aerobic Zone

To determine your target zone multiply your predicted maximum heart rate by 0.70 and 0.85.  This establishes the low and upper end of the aerobic zone. So for a 50-year-old whose predicted maximum heart rate is 173 the lower end of the aerobic zone is 173 times 0.7 which equals 121.  The upper end of the aerobic zone is 173 times 0.85 or 147.

Someone who has been sedentary should start exercising at the lower end of the aerobic zone, while someone who has been physically active can exercise in the upper end. This, of course, assumes that you don’t have any existing heart disease.  And, if you are new to exercise and over age 40 being evaluated by a physician is recommended before embarking on a moderate intensity exercise program.

Borg Perceived Exertion Scale

Another way to gauge and monitor your exercise intensity is use the Borg Perceived Exertion Scale. The scale goes from 6 to 20. By adding a zero to both numbers we get 60 and 200 which correspond to heart rates.  Level 6 is essentially being at rest. The aerobic zone correlates with exercise that is rated 13 to 15. The Borg scale is a useful poor man’s target heart rate calculator.

Rating                                   Perceived Exertion During Exercise

6, 7, 8                                         very, very, light

9, 10                                           very light

11, 12                                         fairly light

13, 14                                         somewhat hard

15, 16                                         hard

17, 18                                         very hard

19, 20                                         very,very hard

The Borg scale is useful when you are exercising and are unable to check your heart rate. By becoming familiar with the scale you can get a good approximation of your exercise intensity. A vast majority of middle-aged adults should strive for a Borg scale level of 13 to 14, younger healthy adults a level of 15 to 16, and senior citizens a level of 11 to 12 in order to get into the aerobic zone.

See related articles.

“Exercise for Sexy Abdominal Muscles”

“Endurance Exercise: Metabolic Responses”

“Exercise Your Way to Losing Weight Fast”

“Exercise for the Ailing Heart”

“Exercise Myths”