You can use your target heart rate to know how hard to exercise to gain the most aerobic benefit from your workout. You can exercise within your target heart rate to either maintain or raise your aerobic fitness level. To raise your fitness level, you can work harder while exercising to raise your heart rate toward the upper end of your target heart rate range. If you have not been exercising regularly, you may want to start at the low end of your target heart rate range and gradually exercise harder.

To take your heart rate during exercise, you can count the beats in a set period of time (for example, 30 seconds) and then multiply by a number to get the number of beats per minute. For example, if you count your heartbeat for 30 seconds, double that number to get the number of beats per minute. You can also wear a heart rate monitor during exercise so you do not have to take your pulse. A heart rate monitor shows your pulse rate continuously, so you see how exercise changes your heart rate. Then, you can work harder or easier to keep your heart working in your target heart rate range.

Target heart rate is only a guide. Each individual is different, so pay attention to how you feel, how hard you are breathing, how fast your heart is beating, and how much you feel the exertion in your muscles.

Do not use the target heart rate measurement if you are taking medicine that affects your heart rate, such as beta-blockers, calcium channel blockers, or digoxin. If you have a heart condition or other chronic disease, talk to your doctor before you start an exercise program.

Try to make physical activity a regular and essential part of your day. But if you haven't been active, start slowly and be sure to talk to you doctor before you add regular exercise to your day. For more information, see the topic Fitness.

Source: McArdle WD, et al. (2007). Training for anaerobic and aerobic power. In Exercise Physiology, 6th ed., pp. 469–507. Philadelphia: Lippincott Williams and Wilkins.