The Study
Effects of resistance training with controlled versus self-selected repetition duration on muscle mass and strength in untrained men
This study showed that if you lift weights with your own pace or a set pace, your muscles get just as strong and big in untrained guys. But it doesn't prove one way is better — just that both work similarly.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
People lifted weights with their legs, some choosing their own speed, others following a strict 2-second-up, 2-second-down rhythm. Both groups got stronger and built more muscle—same amount.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 562 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes—this means you don’t need to count seconds while lifting; just lift until you’re tired, and you’ll get the same results as if you were timing every rep.
- 2Everyone gained 8–10% more strength and 7–10% more muscle.
- 3Those who lifted faster used 47% more total weight over 8 weeks but didn’t gain more muscle or strength.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
PeerJ
Year
2020
Authors
T. S. Chaves, Thaís Marina Pires de Campos Biazon, Lucas Marcelino Eder dos Santos, C. Libardi
Related Content
Claims (6)
When the total amount of weight lifted is the same, changing how slowly you lower the weight during resistance training does not change how much muscle grows.
In untrained men, lifting weights with a self-chosen pace reduces the time muscles are under tension during each rep compared to a slow, controlled pace, but both methods produce the same increases in muscle strength and size when lifts are performed until muscle failure.
In untrained men, lifting weights to muscle failure at 70% of maximum strength with a self-chosen pace increases total work done by 47% over eight weeks compared to a fixed pace, but does not result in greater increases in muscle strength or size.
In untrained men, performing resistance training to muscle failure at 70% of maximum strength for 8 weeks results in measurable increases in muscle strength and muscle size, whether the pace of each repetition is chosen by the person or fixed by a protocol.
In untrained men doing leg extensions twice a week for eight weeks at 70% of their maximum lift, choosing their own lifting speed produces the same increases in muscle strength and thigh muscle size as using a fixed speed, even though each repetition involves less total time under tension and more total repetitions.
In untrained men, lifting weights with either a self-chosen pace or a fixed pace results in the same amount of muscle strength and size gain, as long as the total weight lifted is the same.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.