RIR counts reps left
After your last rep, ask honestly how many more clean reps you could have done. Zero means you hit failure, 2 means two more were in the tank. It keeps you training hard without grinding every set to total failure.
What is RIR or RPE?
RIR is reps in reserve, how many reps you have left; RPE is rate of perceived exertion, a 1 to 10 effort scale.
The quick answer
RIR means reps in reserve: if you stop with 2 good reps left, that is 2 RIR. RPE is rate of perceived exertion on a 1 to 10 scale, and it maps to RIR, so RPE 8 equals about 2 reps left and RPE 10 is all-out failure. Both are ways to gauge effort, and for muscle growth you generally want to train most sets at RPE 7 to 9, or 1 to 3 reps in reserve.
How to think about it
RPE is the flip side
RPE 10 is a maximal effort with nothing left, RPE 9 is one rep left, RPE 8 is two, and so on. Powerlifters often use RPE to autoregulate heavy singles, while bodybuilders use it to keep hypertrophy sets in the effective 7 to 9 range.
Use them to autoregulate
On a strong day you might hit your target reps at RPE 8 and add weight, on a tired day the same weight feels like RPE 9. Adjusting load to a target RIR or RPE keeps effort consistent even when energy varies.
Do this
- Rate your last setAfter each working set, note how many reps you had left to build your judgment of effort.
- Aim for 1 to 3 RIRKeep most growth sets within 1 to 3 reps of failure, which is RPE 7 to 9.
- Calibrate with a real set to failureOccasionally take a set to true failure so you learn what 0 RIR actually feels like.
Keep going
How SUUPR helps
RIR is reps in reserve, how many reps you have left; RPE is rate of perceived exertion, a 1 to 10 effort scale.