Three Ways to Measure Your Activity Intensity

Gauge how hard your body is working when you exercise, to make your workout time well spent!

By Lucy Casale, Contributing Writer

Maybe you take a water aerobics class. Or maybe you shoot hoops with friends after work. You might garden or take long walks. If you already do activities like these, you’re engaging in moderate-intensity aerobic activity.

To stay healthy, adults need 150 minutes of this sort of activity each week. You can break this down into five 30-minute sessions to make it more doable. Or try three 10-minute sessions daily, five times per week. Adults should also do muscle-strengthening activities two or more days per week. These guidelines are for people ages 18 to 64. However, if you are 65 or older, are generally fit and have no health conditions that limit you, you can follow these guidelines.

If 150 minutes is too much for you at first, don’t beat yourself up. Some activity is better than none. Take it slow and work your way up to that goal. However, once you can exercise for those 150 minutes, you’ll most likely want to ensure it’s time well spent.

Can’t tell if what you’re doing qualifies as a moderate-intensity aerobic activity? You can measure your activity intensity to find out. You don’t need special tools or equipment. It’s a self-monitoring process. This measurement helps you figure out how hard your body is working. You can then adjust the intensity of your activity by speeding up or slowing down your movements.

There are three fairly simple ways to measure your activity intensity.

The Talk Test
Level of difficulty: Easy
If your activity is moderate intensity, you should still be able to talk. But you should not be able to sing.

Rate of Perceived Exertion
Level of difficulty: Medium
This measurement has you select a number rating from a scale of 6 to 20. This number should correspond with your perceived exertion, or how hard you think you are working. A rating of 6 represents no exertion. A rating of 20 means you’re working at your maximum. Generally, ratings between 12 and 14 suggest that you’re working at a moderate level of intensity.

Rate of Perceived Exertion Scale
6 – no exertion at all
7.5 – extremely light
9 – very light
11 – light
13 – somewhat hard
15 – hard
17 – very hard
19 – extremely hard
20 – maximal exertion

Try to base your rating on your overall feeling of exertion. Take into account physical sensations. These may include sweating, muscle fatigue, increased heart rate and increased breathing rate. Don’t focus on one factor, like shortness of breath or leg pain.

Target Heart Rate
Level of difficulty: More challenging
If you’re doing a moderate-intensity physical activity, your target heart rate should be 50 to 70 percent of your maximum heart rate.

Your maximum heart rate is based on your age. You can estimate it by subtracting your age from 220.

For a 50-year-old person, the estimated maximum heart rate is 220 - 50 = 170 beats per minute (bpm)
At 50 percent: 170 x 0.50 = 85 bpm
At 70 percent: 170 x 0.70 = 119 bpm

This means that the target heart rate for a 50-year-old person is between 85 and 119 bpm during physical activity. Once you know what your target heart rate is, you can take your pulse to find your heart rate.

Finding your heart rate:
Stop exercising to take your pulse.

If you are physically inactive or you have a health condition such as arthritis, diabetes, heart disease, pregnancy or other symptoms, check with your doctor before starting an exercise program or increasing your activity level. He or she can tell you what types and amounts of activities are safe and suitable for you.