RPEs

RPEs, or ratings of perceived exertion, are subjective measures used to gauge how hard a person feels they are working during physical activity. The most widely used scales are the Borg Rating of Perceived Exertion, including a 6–20 scale (the original Borg 6–20) and the Borg CR-10 scale, a 0–10 scale for maximal or peak effort. OMNI RPE scales provide activity-specific versions. RPE can reflect overall effort as well as sensations such as breathlessness and muscle exertion.

RPEs are used to prescribe and monitor exercise intensity, especially when objective measures like heart rate are unreliable or impractical. Practitioners may target specific ranges (for example, 12–13 on the 6–20 scale for light to somewhat hard effort) or use higher values for interval work. RPE can be applied alone or in conjunction with physiological metrics such as heart rate or VO2, and it is common in athletic training as well as cardiac, pulmonary, or orthopedic rehabilitation programs.

RPEs have demonstrated good reliability and validity in relation to physiological markers across diverse populations. They accommodate individual differences in fitness, medication effects, and environmental factors. Limitations include susceptibility to mood, fatigue, temperature, caffeine, and motivation, as well as the need for instruction and familiarization to ensure consistent use. Cultural or linguistic differences can also influence interpretation. In some cases, such as with beta-blocker use, perceived exertion may provide a more consistent gauge of effort than heart rate alone.

Practical guidance includes educating users on scale descriptors, providing a familiarization period, and using RPE ratings to autoregulate training. During sessions, ask for a rating at specified points and adjust intensity to align with target effort, ensuring alignment with goals and safety.