When you work out, are you doing too much or not enough? There is a simple way to find out by calculating your target heart rate, and the American Heart Association has some tips for your training.  “We don’t want people to over-exercise, and the other extreme is not getting enough exercise,” says Gerald Fletcher, M.D., a cardiologist and professor in the Mayo Clinic College of Medicine in Jacksonville, Fla.

Before you learn how to calculate and monitor your target training heart rate, you have to know your resting heart rate. Your resting heart rate is the number of times your heart beats per minute while it is at rest. You can check it in the morning after you have had a full night’s sleep (hopefully), before you get out of bed.

According to the National Institute of Health, the average resting heart rate is 60-100 beats per minute for adults, including seniors, as well as for children ten years and older.  For well-trained athletes, the resting heart rate is between 40 - 60 beats per minute.

Once you know your resting heart rate, you can determine your target training heart rate. As you exercise, follow these tips on a periodic basis:

• Take your pulse on the inside of your wrist, on the thumb side.
• Use the tips of your first two fingers (not your thumb) to press lightly over the blood vessels in your wrist.
• Count your pulse for 10 seconds and multiply by 6 to find your beats per minute.
• As you work out, stay between 50 percent to 85 percent of your maximum heart rate. This range is your target heart rate. 

This table below illustrates the estimated target heart rates for various age groups.  The maximum heart rate is calculated by taking the number 220 and subtracting your age.  For example, if you are 40 years old, your maximum heart rate is 180.

In the age category closest to yours, read across to find your target heart rate. Heart rate during moderately intense activities is about 50-69% of your maximum heart rate, whereas heart rate during hard physical activity is about 70% to less than 90% of the maximum heart rate.

These figures are averages, so use them as general guidelines.

Age	Target HR Zone 50-85%	Average Maximum Heart Rate, 100%
20 years	100-170 beats per minute	200 beats per minute
30 years	95-162 beats per minute	190 beats per minute
35 years	93-157 beats per minute	185 beats per minute
40 years	90-153 beats per minute	180 beats per minute
45 years	88-149 beats per minute	175 beats per minute
50 years	85-145 beats per minute	170 beats per minute
55 years	83-140 beats per minute	165 beats per minute
60 years	80-136 beats per minute	160 beats per minute
65 years	78-132 beats per minute	155 beats per minute
70 years	75-128 beats per minute	150 beats per minute

The American Heart Association cautions that a few high blood pressure medications lower the maximum heart rate and thus the target zone rate. Therefore, if you are taking medication for high blood pressure, check with your physician to determine if you should be using a lower target heart rate.

Those who have a heart condition or are in cardiac rehab should talk to your doctor about what exercises are best, the appropriate target heart rate, and whether or not monitoring the heartrate during exercise is appropriate. 

If your heart rate is too high, you are straining your heart and need to slow down. If it is too low, and the intensity feels “light” or “moderate/brisk,” you may want to push yourself to exercise a little harder.

During the first few weeks of working out, aim for the lower ranger of your target zone (50 percent) and gradually build up to the higher range (85 percent). After six months or more, you may be able to exercise comfortably at up to 85 percent of your maximum heart rate.

If all this math is making your head hurt, here is a great rule of thumb to remember:  If you are working out and are unable to carry on a conversation, you may be overexerting yourself and should slow down until you can converse easily.