How to measure exercise intensity

Want to know just how hard you are working? Here's how to find out.

Once exercise becomes a regular habit, it’s time to consider just how much (and how hard) you are actually moving. The Department of Health and Human Services recommends that adults get at least 150 minutes of moderate physical activity or 75 minutes of vigorous physical activity or a combination of the two each week. For weight loss, experts recommend doubling those numbers. If you’re like many people, though, you may be a bit confused about whether your activities qualify as moderate or vigorous.

There are two basic ways to measure exercise intensity:

  • How you feel.
  • Exercise intensity is a subjective measure of how hard physical activity feels to you while you're doing it — your perceived exertion. Your perceived level of exertion may be different from what someone else feels doing the same exercise. For example, what feels to you like a hard run can feel like an easy jog to someone who's more fit.
  • Your heart rate. Your heart rate offers a more objective way to measure your exercise intensity. In general, the higher your heart rate during physical activity, the higher the intensity.

Studies show that your perceived exertion correlates well with your heart rate. So if you think you're working hard, your heart rate is likely elevated.

Estimating your intensity
To measure your exercise intensity, you can:

  • Take the talk test. If you can carry on a conversation in brief sentences, you’re probably in the moderate-intensity range. You’ll be breathing faster, developing a light sweat and feeling some strain in your muscles. If you're working at a vigorous intensity, you won’t be able to say more than a few words without catching your breath. (If you can sing while working out, you’re probably in the low-intensity range…so step it up!)
  • Calculate your target heart rate. Use this formula to calculate your target heart-rate range:
    • 220 minus your age = your maximum heart rate
    • Your maximum heart rate multiplied by 0.6 = your lower limit
    • Your maximum heart rate multiplied by 0.85 = your upper limit

During exercise, check your pulse to determine your heart rate. If it’s in the target range, you’re exercising at about the right level. If you find it difficult to find your pulse and count while exercising, it may be a good idea to invest in a heart-rate monitor.

Need a little extra motivation? Find out how many calories you burn doing your favorite activities.