What does RPE stand for in fitness?

In fitness, RPE stands for Rate of Perceived Exertion. It is a self-assessment of how hard physical activity feels, taking into account sensations such as breathing difficulty, muscle fatigue, and overall effort.

The best-known RPE system is the Borg scale, developed by Swedish researcher Gunnar Borg in the 1960s. Its original version runs from 6 to 20, with 6 meaning no exertion and 20 meaning maximal exertion. The range was designed to roughly correspond to a healthy young adult’s heart rate when the score is multiplied by 10, though that relationship is only an estimate.

RPE is useful because the same workout can feel very different to different people. Coaches may prescribe an easy effort around “light” RPE or a demanding interval near “very hard.” The term is sometimes confused with pace or heart rate, but RPE measures subjective effort rather than a single external number. A later Borg CR10 scale uses a shorter 0-to-10-style range.