I've long wondered about the accuracy of those heart-rate monitors on treadmills, elliptical trainers and stationary bicycles — you know, the kind where you wrap your hands around a metal bar and a few seconds later your heart rate is displayed.
This past weekend, while doing a blast of cardio on one of the Expresso bicycles at my gym, the bicycle showed my heart rate to be 181 at one point, as I navigated a rather difficult video course. Now this might have been a cause for concern, seeing as how a heart rate of 181 is 12 beats above what my maximum heart rate should be if I follow the standard formula (220 minus age). But I wasn't concerned at all, because I've gotten into the habit of monitoring my intensity during aerobic activity by using something known as the Borg Scale.
The Borg Scale enables you to rate your level of exercise intensity based on your perception of how hard you're working.
The original Borg scale goes from 6 to 20, with 7 representing "very, very light" intensity, 13 being "somewhat hard," 15 being "hard" and 19 being "very, very hard." A revised Borg Scale with ratings from 1 to 10 was also developed, but I prefer the original because it roughly corresponds to heart rate when multiplied by 10. In other words, a rating of 13 on the original Borg scale would correspond to a heart rate of 130 beats per minute, a rating of 15 would represent a heart rate of about 150, and so on.
For the average person engaging in aerobic activity, a range of 12 to 16 on the original Borg Scale represents an appropriate exercise intensity, according to the American Council on Exercise.
During my aforementioned ride, when the bike put my heart rate at 181, I would have rated my level of exertion on the original Borg scale at 15, which is why I wasn't concerned about the heart-rate information displayed on the bike. Conversely, there have been times when I've been on the treadmill or elliptical trainer and it's displayed a low heart rate, about 115 or so, even though I was sweating and feeling like I was working pretty hard. Given a choice, I'll listen to what my head has to say over the heart-rate monitors on such machines.
Now I'm not recommending that anyone disregard the information displayed by any heart-rate monitor. I'm just saying that it's often helpful to supplement that information with a reality check of your own. Using the Borg Scale is an easy way to do that. And if you're still concerned that your heart rate might be too high, I would recommend simply stopping your activity briefly and checking your heart rate by palpating the pulse at your neck or at your wrist.
The more information you have, the better the decision you will be able to make. That's true of many of life's situations, both inside and outside the gym.