Exercise intensity: How to measure it
- 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 workout to someone who’s more fit.
- Your heart rate. Your heart rate offers a more objective look at exercise intensity. In general, the higher your heart rate during physical activity, the higher the exercise intensity.
Gauging intensity by how you feelHere are some clues to help you judge your exercise intensity.
Moderate exercise intensityModerate activity feels somewhat hard. Here are clues that your exercise intensity is at a moderate level:
- Your breathing quickens, but you’re not out of breath.
- You develop a light sweat after about 10 minutes of activity.
- You can carry on a conversation, but you can’t sing.
Vigorous exercise intensityVigorous activity feels challenging. Here are clues that your exercise intensity is at a vigorous level:
- Your breathing is deep and rapid.
- You develop a sweat after only a few minutes of activity.
- You can’t say more than a few words without pausing for breath.
Overexerting yourselfBeware of pushing yourself too hard too often. If you are short of breath, are in pain or can’t work out as long as you’d planned, your exercise intensity is probably higher than your fitness level allows. Back off a bit and build intensity gradually.
Gauging intensity using your heart rateAnother way to gauge your exercise intensity is to see how hard your heart is beating during physical activity. To use this method, you first have to figure out your maximum heart rate — the upper limit of what your cardiovascular system can handle during physical activity. The basic way to calculate your maximum heart rate is to subtract your age from 220. For example, if you’re 45 years old, subtract 45 from 220 to get a maximum heart rate of 175. This is the maximum number of times your heart should beat per minute during exercise. Once you know your maximum heart rate, you can calculate your desired target heart rate zone — the level at which your heart is being exercised and conditioned but not overworked. The American Heart Association and the Centers for Disease Control and Prevention recommend a general target heart rate of:
- Moderate exercise intensity: 50 to about 70 percent of your maximum heart rate
- Vigorous exercise intensity: 70 to about 85 percent of your maximum heart rate
How to determine your target zoneUse an online calculator to determine your desired target heart rate zone. Or, here’s a simple way to do the math yourself. If you’re aiming for a target heart rate in the vigorous range of 70 to 85 percent, you would calculate it like this:
- Subtract your age from 220 to get your maximum heart rate.
- Calculate your resting heart rate by counting your heart beats per minute when you are at rest, such as first thing in the morning. It’s usually somewhere between 60 and 100 beats per minute for the average adult.
- Calculate your heart rate reserve (HRR) by subtracting your resting heart rate from your maximum heart rate. Your HRR is your resting heart rate subtracted from your maximum heart rate.
- Multiply your HRR by 0.7 (70 percent). Add your resting heart rate to this number.
- Multiply your HRR by 0.85 (85 percent). Add your resting heart rate to this number.
- These two numbers are your training zone heart rate for vigorous intensity exercise. Your heart rate during exercise should be between these two numbers.
How to tell if you’re in the zoneSo how do you know if you’re in your target heart rate zone? Use these steps to check your heart rate during exercise:
- Stop momentarily.
- Take your pulse for 15 seconds. To check your pulse over your carotid artery, place your index and third fingers on your neck to the side of your windpipe. To check your pulse at your wrist, place two fingers between the bone and the tendon over your radial artery — which is located on the thumb side of your wrist.
- Multiply this number by 4 to calculate your beats per minute.