Subjective assessment of the demands of a training session. Gunnar Borg, a Swedish physiologist, devised a set of ratings (called the Borg scale) which numerically grades perceived exertion. His original rating consisted of 15 grades, from very, very light exertion to very, very hard exertion. This has been modified into the New Borg Scale to take into account the fact that exercisers become more sensitive to changes of exertion at higher work rates:
Adapted from Noble, et al. (1983) Medicine and Science in Sports and Exercise. 15 (2): 523.
The perceived ratings follow changes in heart rate (which is directly related to exercise intensity) quite closely, indicating that perceived exertion is a reasonable indicator of actual exertion. A record of perceived exertion in a training diary can be a very useful means of monitoring exercise intensity and fitness. As fitness improves, a person should be able to exercise at higher ratings of perceived exertion with less fatigue. If a person feels unusually tired after exercising at low ratings of perceived exertion, it probably means that he or she needs a rest.
RATINGS OF PERCEIVED EXERTION (RPE) SCALE: THE NEW BORG SCALE
PERCEPTION OF EFFORT
nothing at all
very, very weak (just noticeable)
very, very strong (almost maximal)
>10 (any number)
Subjects: Medicine and Health.