Training · Moderate evidence
Proximity to Muscular Failure
Training to failure is not mandatory; sets finished with a few reps in reserve already produce gains, and hypertrophy improves as sets get closer to failure.
Meta-analyses and meta-regression · 3 sources · 2 min
What the studies show
- Training to failure was not superior to stopping short of it for hypertrophy.
- Hypertrophy improves as sets end closer to failure; strength increased similarly across a wide range of RIR.
- Strength and muscle mass gains were similar between failure and non-failure in meta-analysis.
How Letz applies it
The plan targets 1 to 3 reps in reserve (2 to 4 for beginners); the guided workout never requires failure and treats pain or breakdown in technique as a cue to stop.
Numbers derived from this rule
| Parameter | Range | Weight | Rule |
|---|---|---|---|
| Reps in reserve at the end of the set | 1–3 RIR1 variant by context | 70% | Ending sets with 1 to 3 reps in reserve already produces gains; absolute failure is not necessary and compromises recovery.Proximity to Muscular Failure · Load and Volume Autoregulation |
Who it applies to
Adults in resistance training with effort monitored by RIR or velocity loss.
Limits
Estimating reps in reserve is imprecise in beginners; frequent failure increases fatigue and reduces the quality of subsequent sets.
Sources
- Refalo et al., Sports Medicine, 2023 DOI 10.1007/s40279-022-01784-y
- Robinson et al., Sports Medicine, 2024 DOI 10.1007/s40279-024-02069-2
- Grgic et al., Journal of Sport and Health Science, 2022 DOI 10.1016/j.jshs.2021.01.007
More in Training
- Resistance Training, Strength, and HypertrophyVarious training prescriptions improve strength and hypertrophy; heavier loads favor strength, and multiple sets favor hypertrophy.
- Weekly Volume: Sets per Muscle GroupMore weekly sets per muscle produce greater hypertrophy, with diminishing returns; for strength, moderate volumes already capture most of the gains.
- Frequency: training each muscle at least twice per weekTraining a muscle group twice a week is superior to once for hypertrophy; for strength, higher frequency helps primarily because it distributes volume more effectively.
- Load and rep rangeLight and heavy loads produce similar hypertrophy when sets are taken close to failure; heavy loads are superior for maximizing strength gains.