Reps in Reserve

Reps in reserve, abbreviated RIR, names the count of additional reps a trainee could perform on a set before reaching technical failure. RIR 0 indicates failure with the last rep completed. RIR 2 indicates two reps remained at set termination. The measure pairs with RPE as the dominant prescriptive language of evidence-based strength programming post-2010.

How RIR maps to RPE

The RIR-to-RPE conversion is direct. RPE 10 equals RIR 0. RPE 9 equals RIR 1. RPE 8 equals RIR 2. RPE 7 equals RIR 3. RPE 6 equals RIR 4 or more. Most contemporary strength programs prescribe in RIR rather than RPE because the count is more concrete than the felt-effort scale and harder to drift in self-rating.

The accuracy of self-reported RIR climbs with training experience. Beginners systematically over-report RIR: the trainee claims RIR 3 when objectively only one rep remained. Zourdos et al. (2016) validated the underlying scale; Helms et al. (2016) set out the framework for applying RIR-based RPE to resistance training.

How kettlebell programming uses RIR

Kettlebell bell-weight granularity (4 kg jumps) blocks fine RIR adjustment on heavy lifts. A trainee pressing 24 kg at RIR 2 cannot drop to 22 kg to hit RIR 3. The next bell is 20 kg, which jumps to RIR 5 or 6. The RIR target gets absorbed by rep count rather than load. A 24 kg press for 4 reps at RIR 2 becomes 24 kg for 6 reps at RIR 2 in the next progression.

For density-based protocols, RIR applies per round of the complex rather than per individual set. The trainee tracks the RIR drift across the conditioning block. Round 1 at RIR 4 climbing to round 8 at RIR 1 indicates correct prescription. Round 1 already at RIR 2 indicates the load or density needs adjustment.

The RIR-RPE framework from Zourdos and Helms underlies most modern programming. The same prescriptive logic extends to intensification phases (lower RIR targets, RIR 0 to 2) and to accumulation phases (higher RIR targets, RIR 3 to 5).

For the broader scale interpretation, see RPE training.

Used in: Program 01 — Kettlebell Complex