Perceived Exertion (Borg Rating of Perceived Exertion Scale)
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, your exertion rating based on a 6 to 20 rating scale, may provide a fairly good estimate of your actual heart rate during physical activity* (Borg, 1998).
As you exercise you can rate your perceived exertion using several anchors. These include a rating of 6 perceiving “no exertion at all” to 20 perceiving a “maximal exertion” of effort. Practitioners generally agree that perceived exertion ratings between 12 to 14 on the Borg Scale suggests that physical activity is being performed at a moderate level of intensity. During activity, use the Borg Scale to assign numbers to how you feel (see instructions below). Self-monitoring how hard your body is working can help you adjust the intensity of the activity by speeding up or slowing down your movements.
Through experience of monitoring how your body feels, it will become easier to know when to adjust your intensity. For example, a walker who wants to engage in moderate-intensity activity would aim for a Borg Scale level of “somewhat hard” (12-14). If he describes his muscle fatigue and breathing as “very light” (9 on the Borg Scale), he would want to increase his intensity. On the other hand, if he felt his exertion was “extremely hard” (19 on the Borg Scale), he would need to slow down his movements to achieve the moderate-intensity range.
*A high correlation exists between a person’s perceived exertion rating times 10 and the actual heart rate during physical activity; so a person’s exertion rating may provide a fairly good estimate of the actual heart rate during activity (Borg, 1998). For example, if a person’s rating of perceived exertion (RPE) is 12, then 12 x 10 = 120; so the heart rate should be approximately 120 beats per minute. Note that this calculation is only an approximation of heart rate, and the actual heart rate can vary quite a bit depending on age and physical condition. The Borg Rating of Perceived Exertion is also the preferred method to assess intensity among those individuals who take medications that affect heart rate or pulse.