Training · Moderate evidence
Load and rep range
Light and heavy loads produce similar hypertrophy when sets are taken close to failure; heavy loads are superior for maximizing strength gains.
Meta-analyses and network meta-analysis · 3 sources · 2 min
What the studies show
- Hypertrophy was similar between low and high loads when training was carried out close to failure.
- Maximal strength increased more with heavier loads.
- The 6 to 12 rep range is practical because it balances mechanical tension, time efficiency, and fatigue, not because it is the only effective range.
How Letz applies it
Muscle gain and body recomposition goals use 6 to 12 reps; athletic performance uses 3 to 6; bodyweight-only workouts use 8 to 20 reps. The goal-specific rep range applies to the primary compound lifts — isolation and core work follow standard ranges, since maximal strength is not prescribed on abdominal exercises.
Numbers derived from this rule
| Parameter | Range | Weight | Rule |
|---|---|---|---|
| Reps per set | 6–12 reps2 variants by context | 60% | Broad ranges work when effort is high; 6 to 12 is practical for mass, 3 to 6 for maximal strength, and up to 20 with bodyweight.Load and rep range · Resistance Training, Strength, and Hypertrophy |
Who it applies to
Healthy adults; ranges of approximately 5 to 30 repetitions performed with high effort.
Limits
Very long sets with light loads require high discomfort tolerance and sound technique; there is no magic rep range, only the intent to push hard.
Sources
- Schoenfeld et al., Journal of Strength and Conditioning Research, 2017 DOI 10.1519/JSC.0000000000002200
- Lopez et al., Medicine & Science in Sports & Exercise, 2021 DOI 10.1249/MSS.0000000000002585
- Schoenfeld et al., Sports (Basel), 2021 DOI 10.3390/sports9020032
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.
- Rest Between SetsRest intervals of two minutes or more favor strength and hypertrophy in compound exercises; short rest intervals work well when time is constrained.