How to measure intensity: How hard am I working?

There are several methods of measuring intensity during a workout. Three common methods used are heart rate, rate of perceived exertion (RPE) and the talk test. These methods may be used alone or in combination.

Heart Rate:

You can determine your maximum heart rate by subtracting your age from 220. To determine a training zone, multiply that number by a lower percentage and again by a higher percentage. For example: I am 47 years old and I would like to train between 65% and 85% of my maximum heart rate. I would calculate my training zone as follows. Maximum heart rate: 220-47=173 bpm

Lower training level: 173 x 0.65=112 bpm

Upper training level: 173 x 0.85=147 bpm

I would therefore attempt to keep my heart rate between 112 bpm and 147 bpm during my workout. It will of course be lower during the warm up and cool down.

Heart rate training is just an estimate. It is a good place to start and track changes over time. In other words, when you begin exercising you may find that your heart rate goes up quickly and comes down slowly. After training for a month, your heart rate may go up more slowly and come down quickly when doing the same program. This indicates that the same amount of work is easier for you to do and the heart has become more efficient at handling that workload. Many medications and stimulants will affect heart rate.

Rate of Perceived Exertion (RPE):

This is simply a scale which an individual uses to determine how hard he/she is working. It is also called the Borg scale and is usually rated between 1 and 10 or 6 and 20 depending upon which scale is used.

The Borg Rating of Perceived Exertion (RPE) is a way of measuring physical activity intensity level. Perceived exertion is how hard you feel like your body is working. It is based on the physical sensations a person experiences during physical activity, including increased heart rate, increased respiration or breathing rate, increased sweating, and muscle fatigue. Although this is a subjective measure, a person’s exertion rating may provide a fairly good estimate of the actual heart rate during physical activity* (Borg, 1998).

Instructions for Borg Rating of Perceived Exertion (RPE) Scale

While doing physical activity, we want you to rate your perception of exertion. This feeling should reflect how heavy and strenuous the exercise feels to you, combining all sensations and feelings of physical stress, effort, and fatigue. Do not concern yourself with any one factor such as leg pain or shortness of breath, but try to focus on your total feeling of exertion.

Look at the rating scale below while you are engaging in an activity; it ranges from 6 to 20, where 6 means “no exertion at all” and 20 means “maximal exertion.” Choose the number from below that best describes your level of exertion. This will give you a good idea of the intensity level of your activity, and you can use this information to speed up or slow down your movements to reach your desired range.

Try to appraise your feeling of exertion as honestly as possible, without thinking about what the actual physical load is. Your own feeling of effort and exertion is important, not how it compares to other people’s. Look at the scales and the expressions and then give a number.

6 No exertion at all

7 Extremely light (7.5) 8

9 Very light

10

11 Light

12

13 Somewhat hard

14

15 Hard (heavy)

16

17 Very hard

18

19 Extremely hard

20 Maximal exertion

9 corresponds to “very light” exercise. For a healthy person, it is like walking slowly at his or her own pace for some minutes

13 on the scale is “somewhat hard” exercise, but it still feels OK to continue.

17 “very hard” is very strenuous. A healthy person can still go on, but he or she really has to push him- or herself. It feels very heavy, and the person is very tired.

19 on the scale is an extremely strenuous exercise level. For most people this is the most strenuous exercise they have ever experienced.

Borg RPE scale © Gunnar Borg, 1970, 1985, 1994, 1998

Talk Test:

The talk test is a simple way to measure relative intensity. As a rule of thumb, if you’re doing moderate-intensity activity you can talk, but not sing, during the activity. If you’re doing vigorous-intensity activity, you will not be able to say more than a few words without pausing for a breath. If you cannot talk, you are working at a high intensity which you can sustain for very brief periods.