Logging RPE and RIR

RPE (Rate of Perceived Exertion) in resistance training usually uses a 1–10 repetition-based scale: RPE 10 = no more reps possible, RPE 9 = one more rep, RPE 8 = two more, and so on. RIR (Reps In Reserve) is the inverse statement of the same thing — RIR 0 = failure, RIR 2 = could have done two more. They are interchangeable: RPE ≈ 10 − RIR.

Why log it: load and reps alone do not capture how hard a set was. 100 kg × 8 at RIR 4 and at RIR 0 are very different doses despite identical Training Volume Load. Recording effort lets the program:

• Auto-regulate — adjust today's load to hit a target RIR rather than a fixed number, accommodating daily readiness (see RPE / RIR Autoregulation).
• Cap fatigue — keep most working sets in a productive RIR 1–3 band for hypertrophy, reserving RIR 0 for tested maxes.
• Drive progression — when a prescribed load drifts to an easier RPE over weeks, that is the signal to add load (see Applying Progressive Overload).

Limitations: RPE/RIR rating accuracy improves with experience; novices tend to underrate effort (think they have more reps left than they do). Calibrate against occasional sets taken genuinely to failure. For cardio, a different (often Borg 6–20 or 0–10 session) RPE is used — see Cardio RPE and Session RPE.

• Resistance RPE: 1–10 rep-based. RPE 10 = failure; RPE 8 = ~2 reps left.
• RIR is the complement: RPE ≈ 10 − RIR. RIR 0 = failure.
• Logging effort makes equal-volume sets comparable and enables auto-regulation.
• Hypertrophy work commonly targets RIR 1–3; max testing uses RIR 0 / RPE 10.
• Novices systematically underestimate effort; calibrate with occasional failure sets.