Anything from about 6 to 30 reps builds similar muscle if sets end close to failure, with 6–12 reps being most time-efficient. For maximal strength, heavy sets of 1–6 reps at 80–95% of your 1RM work best. Most lifters should mix heavy main lifts with moderate-rep accessories.
The number of reps per set changes which adaptations you emphasise. Muscle growth is similar across a wide range of loads when sets go close to failure, while maximal strength favours heavy loads.
Summary of the low- vs high-load meta-analyses (Schoenfeld 2017, Lopez 2021): growth is similar across a wide range when sets go close to failure; maximal strength clearly favours heavy loads.
| Reps per set | % 1RM (approx.) | Muscle growth | Max strength | Fatigue / joint stress |
|---|---|---|---|---|
| 1–5 | 85–100% | Good (needs more sets) | Best | High on joints, low on lungs |
| 6–12 | 67–85% | Best per time spent | Good | Moderate |
| 13–30 | 40–65% | Similar if near failure | Weaker | High discomfort, burning |
Relative hypertrophy (near failure)
Relative 1RM strength gain
Schematic illustration of the direction of findings, not exact effect sizes.
Enter your 1RM (or estimate it with the RPE calculator) to get a starting load for each rep target. Brzycki up to 10 reps, Epley above.
| Reps to failure | Load (lb) | Load (kg) | % 1RM |
|---|---|---|---|
| 1 | 275 | 125 | 100% |
| 3 | 260 | 118 | 94% |
| 5 | 245 | 111 | 89% |
| 8 | 220 | 100 | 81% |
| 10 | 205 | 94 | 75% |
| 12 | 195 | 89 | 71% |
| 15 | 185 | 83 | 67% |
| 20 | 165 | 75 | 60% |
| 25 | 150 | 68 | 55% |
| 30 | 140 | 62 | 50% |
| Outcome | Effect | Evidence |
|---|---|---|
| Muscle growth (low vs. high load) | Similar when near failure | Strong |
| Max strength (1RM) | Clearly favours heavy loads | Strong |
| Muscular endurance | Favours high reps | Moderate |
| Joint stress | Higher with heavy loads | Limited |
“8–12 reps is the only hypertrophy range.”
FalseSets from ~6 to 30 reps build similar muscle when close to failure.
“High reps only 'tone' muscles.”
FalseToning isn't a separate process; high reps near failure build muscle.
For: Intermediates
For: Lifters with achy joints
Schoenfeld et al. · J Strength Cond Res · 2017
For your training: Choose heavy sets for strength, any reasonable range for size.
Schoenfeld et al. · J Strength Cond Res · 2015
For your training: High reps work for growth even in experienced lifters.
Lopez et al. · Med Sci Sports Exerc · 2021
For your training: Load choice is mainly a strength and preference decision.
Anywhere from about 6 to 30 reps per set, as long as sets end close to failure. 6–12 is the most time-efficient.
Yes. Sets of 20–30 reps to near failure built similar muscle to 8–12 reps in trained men.
1–6 reps at 80–95% of 1RM, because strength gains are specific to heavy loads.
Usually yes: heavy work on main lifts, moderate and higher reps on accessories gives the best of both.
Ranked by citations. Metadata from OpenAlex (CC0).
Schoenfeld et al. · J Strength Cond Res · 2017 · 0 citations · Meta-analysis
Schoenfeld et al. · J Strength Cond Res · 2015 · 0 citations · Study
Lopez et al. · Med Sci Sports Exerc · 2021 · 0 citations · Meta-analysis
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