Load & rep range
// What the research shows
The meta-analysisMeta-analysis A study of studies: the results of many individual studies are pooled statistically. More in the glossary → by Schoenfeld et al. (2017) compared 21 studies in which all sets went to failureMuscular failure The point where, despite full effort, you can't complete another clean rep. More in the glossary →. HypertrophyHypertrophy (muscle growth) A muscle getting bigger, mainly through thicker muscle fibres. More in the glossary → didn't differ between light (≤60% 1RM) and heavy loads. For 1RM strength, heavy training was clearly superior; for isometric strength it was not.
// In practice
- For hypertrophy, roughly 5–30 reps per set works, as long as you get close to failure.
- Very light sets are more fatiguing and unpleasant. A mix is most practical for many people.
- If you want a bigger 1RM, train heavy regularly.
// Limitations & open questions
The data apply to sets taken to failure. How well light loads work with more reps in reserveRIR (reps in reserve) How many more reps you could have done at the end of a set. 0 RIR means failure. More in the glossary → is less clear.
// Sources
// More from Training
Training volume
More hard sets per muscle per week lead to more growth, but each extra set adds a bit less than the one before.
Training frequency
For muscle growth it doesn't matter much how many days you spread your sets over. For strength, practising the lift more often helps.
Proximity to failure (RIR)
For muscle growth it pays to train close to failure. For strength it matters much less.
Range of motion & stretched position
Full range of motion is a good default. Training in the stretched position seems especially important for growth.