Alpha Progression
RPE
RPE stands for rating of perceived exertion. In strength training, set RPE is a subjective 1-to-10 rating of how demanding a set was relative to the lifter's current repetition capacity. The upper end of the scale is commonly anchored to reps in reserve.
On the widely used RIR-based scale, RPE 10 means no further complete repetition was possible, RPE 9 means about one repetition remained, RPE 8 about two, and RPE 7 about three. Half steps can express an in-between judgment, such as RPE 8.5. These are practical anchors, not exact conversions. The relationship becomes less distinct for easier sets, and different coaches may define the lower part of the scale differently.
RPE records effort level, whereas a percentage of 1RM records load-based training intensity. A set at 70% 1RM could be RPE 6 when stopped early or RPE 10 when continued until no further repetition is possible. RPE can therefore help compare sets when daily performance changes or when exercises do not lend themselves to accurate percentage prescriptions.
To make ratings more useful, define the endpoint before the set: full intended range of motion, the normal repetition tempo, and acceptable technique. Rate the set immediately after it ends, then compare the estimate with what happens in later sessions. A systematic review and meta-analysis of RIR prediction accuracy found meaningful variation between estimates and actual repetitions to failure, so RPE should not be treated as an objective measurement. Practice and ratings made closer to failure can improve calibration, but uncertainty remains.
The label RPE is also used for whole-session or cardiovascular exertion, including Borg scales with different number ranges. A session RPE summarizes the workout; a set RPE evaluates one set. Recording the scale and unit avoids mixing these distinct measures, and pain should be logged separately rather than folded into a high RPE score.
