An idea that struts its way around the gym is that slower muscle contractions are better for building muscle…
Is that true?
Current research suggests that for muscle hypertrophy (growth), a slower tempo isn’t necessarily better!
But first, here are useful terms to know:
- Concentric contraction: The phase of the movement where the muscle actively ‘shortens’ (usually when you lift the weight ‘up’)
- Eccentric contraction: The phase of the movement where the muscle actively ‘lengthens’ (usually when you lower the weight ‘down’).
What tempo promotes hypertrophy?
Tempo appears to have little effect – a wide range of concentric and eccentric tempos (~0.25‒4.5 seconds each phase) promotes muscle hypertrophy.
While more research is needed, logic dictates that the weight should be adequately controlled. This may not be achieved if you let gravity do too much of the work during the eccentric phase.
What matters more than tempo is taking sets close to failure, training volume, and progressive overload.
Does tempo not matter then?
Tempo could be more important for power development, specifically lifting fast with intent during the concentric phase.
TL;DR:
- If muscle hypertrophy is your goal: Lift fast or slow (~0.25‒4.5 seconds up and ~0.25‒4.5 seconds down) with enough control.
- If power development is your goal: Lift fast up.
- If you want both: Lift fast up and control down.
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References:
- Balachandran et al. (2022) (PMID: 35544136)
- Enes et al. (2025) – How slow should you go? A systematic review with meta-analysis of the effect of resistance training repetition tempo on muscle hypertrophy
- Schoenfeld et al. (2015) (PMID: 25601394)
