What are RIR and RPE in strength training?

RIR and RPE describe the same set from opposite directions

RIR counts the repetitions you believe remained before you could no longer complete another repetition with the intended technique. A higher RIR therefore means an easier set. RPE rates the overall effort of the set; on a resistance-training-specific 1–10 scale, a higher number means a harder set.

The two can be translated approximately near the end of a set. RPE 10 is commonly used for 0 RIR, RPE 9 for 1 RIR, RPE 8 for 2 RIR, and RPE 7 for 3 RIR. The relationship becomes less precise farther from failure, so the number should be treated as a decision aid rather than a guarantee.

• RPE 10 ≈ 0 RIR: no additional good repetition
• RPE 9 ≈ 1 RIR
• RPE 8 ≈ 2 RIR
• RPE 7 ≈ 3 RIR

How can RIR guide weight and repetition choices?

Choose a target repetition range and an intended RIR before the set. If the program calls for 8–10 repetitions at 2 RIR, stop when you judge that about two technically acceptable repetitions remain. If you reach ten repetitions with substantially more than two left, the load may be light for that target. If you reach the lower end with none left, it may be heavy.

Adjust gradually and compare similar exercises, technique standards, and rest periods. RIR can support autoregulation when daily readiness changes, but it does not replace the structure of a program or the need to record the load and completed repetitions.

How accurate is an RIR estimate?

Research suggests RIR estimates tend to be more useful when they are made close to task failure. Accuracy can vary with training experience, load, exercise, repetition range, and familiarity with the scale. Lighter, longer sets can be particularly difficult to judge.

Calibrate the skill over time. Occasionally compare your estimate with what actually happens when an appropriate set is continued, without turning every set into a failure test. Technique should remain the boundary: a repetition that requires a different movement standard should not be counted as a clean repetition in reserve.

• Estimate after the set, using the same definition each time
• Keep exercise technique and range of motion comparable
• Expect more uncertainty on lighter, high-repetition sets
• Use multi-week patterns rather than one isolated rating

What should you record in a workout log?

Record the exercise, load, completed repetitions, and the RIR or RPE estimate. Rest duration and a short technique note add context when the next session feels different. This makes the effort rating interpretable instead of leaving it as a number without conditions.

Korvelis keeps set-level performance and notes alongside exercise history. When you review a trend, ask whether the same load became easier, whether more repetitions were completed at a similar RIR, or whether the rating changed because rest, technique, or recovery conditions changed.