To Your Health
July, 2009 (Vol. 03, Issue 07)
How Is Target Heart Rate Determined?
Your target heart rate for cardiovascular benefit (60-85 percent of maximum heart rate) is actually determined via a precise mathematical formula that involves several steps.
This example is based on a 24-year-old with an average resting heart rate of 78 beats per minute.
Step 1: The first step is to determine your resting heart rate, which can be done by taking your pulse as soon as you wake up in the morning, before getting out of bed. Take one-minute readings over the course of three days and divide by three to get your average resting rate. (For example, 76 plus 80 plus 78 divided by three = an average resting heart rate of 78 beats per minute.)
Step 2: Subtract your age from 220 to determine your maximum heart rate. For example, the maximum heart rate for a 24-year-old is 220 - 24 = 196.
Step 3: Subtract your resting heart rate from your maximum heart rate. Using our examples above, 196 - 78 = 118, which represents your heart rate reserve.
Step 4: Calculate the lower limit (60%) of your target heart rate. In this case, multiply 118 by 0.6, which yields 70.8, and add that number to your resting heart rate (70.8 plus 78 = 148.8). So, your lower limit is approximately 149 beats per minute.
Step 5: Calculate the upper limit (85%) of your target heart rate by multiplying 118 by 0.8, which yields 87.2; add that number to your resting heart rate (94.4 + 78 = 172.4). That means your upper limit is approximately 172 beats per minute.
Step 6: Divide your totals from steps 4 and 5 (in our example, 149 and 172) by the number 6; this will give you your lower and upper target heart rate limits (beats per 10 seconds). 148.8 / 6 = 24.8 and 172.4 / 6 = 28.7. That means if you take your pulse for 10 seconds while exercising and you're between 25 and 29 beats during those 10 seconds, you're achieving your target heart rate.
Chelsea Cooper, MPA, CPT, is certified by the National Academy of Sports Medicine as a personal trainer, performance enhancement specialist, and rehab and exercise specialist. To learn more, visit www.trainwithchelsea.com.