RPE (Rate of Perceived Exertion)

RPE: what is it?

Rate of Perceived Exertion started as a 6-to-20 scale for cardio (the Borg scale) and was later adapted into a 1-to-10 scale for lifting. The lifting version is anchored to reps in reserve: the number tells you how close the set came to failure, whatever the weight on the bar. That makes it the most practical way to prescribe effort for a client whose strength changes from week to week.

The RPE scale for strength training

The modern lifting scale runs from 1 to 10 and is read in half steps. Each value maps to a number of reps the lifter could still have done with good form.

RPE versus percentage of 1RM

Prescribing "80% of your max" assumes the max is accurate today. It rarely is: sleep, stress, a cold or a new job move a client's real strength up or down by several percent. An RPE prescription like "5 reps at RPE 8" self-adjusts. On a good day the client loads more, on a bad day less, and the training stimulus stays where you wanted it.

The two approaches are not rivals. Many coaches write percentages for the first working set and let RPE guide the load on the following sets, or use RPE caps on top of a percentage plan ("3 x 5 at 80%, do not exceed RPE 8").

How to teach RPE to a client

Beginners under-rate hard sets and over-rate easy ones, mostly because they have never actually reached failure. The fastest fix is one supervised set taken to technical failure on a safe exercise (leg press, machine row). Once the client has felt RPE 10, RPE 8 becomes a real reference rather than a guess.

Bar speed is the second anchor. On compound lifts, the last rep of an RPE 8 set is visibly slower than the first, and an RPE 9 rep grinds. Filming a set and reviewing it together tightens the client's ratings within a few weeks.

• Ask for the rating immediately after the set, before the number gets tidied up.
• Rate the last rep, not the whole set.
• Use half points: 8.5 is a legitimate answer.
• Expect ratings to be more accurate on compound lifts than on isolation work.

Common mistakes

The most frequent error is prescribing RPE to a client who has no idea what failure feels like; the numbers are noise until that reference exists. The second is chasing RPE 10 every set. Most hypertrophy and strength work lives between RPE 7 and 9, with RPE 10 reserved for the last set of an exercise or a testing week.

Finally, RPE is a rating of the set, not of the whole workout. A client who "felt tired" can still have done every set at RPE 7. Keep the two separate in your notes.