Repetition tempo
// 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. (2015; 8 studies) found similar hypertrophy with repetition durations from 0.5 to 8 seconds. Very slow training with over 10 seconds per rep appears inferior, though few well-controlled studies exist. A newer meta-analysis (2025, as a pre-printPre-print A study that's already public but hasn't yet been reviewed by independent experts. More in the glossary →) that looks at the lowering and lifting phases separately broadly confirms this: neither phase shows a clear advantage.
// In practice
- Lower under control, lift at a normal to brisk pace. No need to count a fixed tempo.
- Skip super-slow reps of 10+ seconds if building muscle is the goal.
- More important than tempo: get close enough to failureMuscular failure The point where, despite full effort, you can't complete another clean rep. More in the glossary → and use a full range of motionRange of motion (ROM) How far a joint moves during an exercise, from the stretched to the shortened position. More in the glossary →.
// Limitations & open questions
Only 8 studies in the main meta-analysis, many with untrained people. The newer analysis was not yet final when this entry was written.
// 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.
Load & rep range
Muscles grow similarly with light and heavy loads as long as sets are hard. Maximal strength needs heavy loads.