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What is RIR (Reps in Reserve)?

Paul Hummel Last reviewed June 10, 2026 3 min read
What is RIR (Reps in Reserve)?
Quick answer

RIR (Reps in Reserve) is the number of reps you could still perform before reaching muscle failure. It is a well-established method for controlling training intensity with precision.

The scale

A working set taken to RIR 0 ends in complete muscle failure. At RIR 2, you stop the set two reps short of failure. The concept is considered a reliable complement — or alternative — to classic percentage-of-1RM programming (Helms et al., 2016).

Chart: RIR ranges by training goal

Recommended RIR ranges

GoalRIR
Hypertrophy (primary range)0–3
Strength (heavy compound lifts)1–3
Recovery phases / deload4–5

How accurate are RIR estimates?

Experienced lifters judge their RIR considerably better than beginners do (Hackett et al., 2017). Accuracy improves with training experience and with deliberately reflecting on every set after you finish it.

An RIR of 0 to 3 represents the hypertrophy-optimal intensity zone (Schoenfeld & Grgic, 2017). Routinely training at RIR 4 or higher measurably weakens the growth stimulus.

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Sources

  1. Helms, E. R., et al. (2016). RPE and Velocity Relationships for the Back Squat, Bench Press, and Deadlift in Powerlifters. J Strength Cond Res, 31(2). PubMed
  2. Hackett, D. A., et al. (2017). Estimation of repetitions to failure for monitoring resistance exercise intensity. J Strength Cond Res, 31(8). PubMed
  3. Schoenfeld, B. J., & Grgic, J. (2017). Evidence-based guidelines for resistance training volume to maximize muscle hypertrophy. Strength Cond J, 40(4). PubMed
This content is for general informational purposes only and is not a substitute for medical, nutritional, or therapeutic advice. If you have a medical condition, are pregnant, or take medication, please consult a qualified professional. Recommendations apply to healthy adults.