Back to glossary
Exercise & fitness

RIR (Reps in Reserve)

DERIR (Wiederholungen in Reserve)

Reps in Reserve (RIR) is an autoregulation method for prescribing and grading resistance-training intensity by asking the lifter to estimate how many additional repetitions could be performed at the end of a set before reaching momentary muscular failure. An RIR of 0 corresponds to a maximal effort (RPE 10 on a 0-10 scale), RIR 1 means one rep short of failure, and RIR 3 means three reps in reserve. Validated by Zourdos and colleagues (J Strength Cond Res, 2016), the RIR-based RPE scale correlates strongly with bar-velocity and with percentage of 1-rep maximum (1RM) in both experienced and novice lifters, with stronger correlations at higher intensities. Compared with rigid %1RM prescriptions, RIR adapts to daily readiness fluctuations and is therefore favoured in modern hypertrophy and powerlifting programming.

Sources

  1. Zourdos MC, Klemp A, Dolan C, et al.. (2016). Novel resistance training-specific rating of perceived exertion scale measuring repetitions in reserve. *Journal of Strength and Conditioning Research*doi:10.1519/JSC.0000000000001049
  2. Helms ER, Cronin J, Storey A, Zourdos MC. (2016). Application of the Repetitions in Reserve-Based Rating of Perceived Exertion Scale for Resistance Training. *Strength and Conditioning Journal*doi:10.1519/SSC.0000000000000218
  3. Bastos V, Machado S, Teixeira DS. (2024). Feasibility and Usefulness of Repetitions-In-Reserve Scales for Selecting Exercise Intensity: A Scoping Review. *Perceptual and Motor Skills*doi:10.1177/00315125241241785