The Study
Effects of Rest Interval Length on Muscle Hypertrophy in Amateur Bodybuilders
This study is like a fair race where three groups of bodybuilders trained the same way, but each group rested for a different amount of time between sets. The ones who rested longer grew bigger muscles and got stronger. Because they were randomly assigned, we can guess that the rest time made the difference—not just luck.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
If you lift weights and rest only 60 seconds between sets, you can't do as many reps or lift as much weight later — but if you rest 90 seconds, you can keep going strong and build more muscle.
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 555 / 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 — 8–9% muscle growth is a big, noticeable difference for bodybuilders, and 10% strength gain means lifting noticeably heavier weights.
- 2After 10 weeks: 60s rest → muscles grew 4%; 90s rest → muscles grew 8%; 180s rest → muscles grew 9%.
- 3Strength went up 6% with 60s rest, but 10% with 90s or 180s rest.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Qubahan Journal of Coaching and Sports Sciences
Year
2025
Authors
Yusufcan Keskin, Chibuzo Maduka Uzoho, Chyavan Mohammed Abdulrahman
Related Content
Claims (8)
The amount of time between sets during weight training does not definitively change the point at which increasing workout volume no longer leads to more muscle growth.
In amateur bodybuilders, greater total training volume is linked to larger muscle growth, and this relationship is partly explained by the capacity to maintain high-quality effort across multiple sets.
Amateur bodybuilders who rest 90 to 180 seconds between sets gain more strength in the bench press and back squat than those who rest only 60 seconds, with strength increases of 9.3–10.7% compared to 5.9–6.3%.
Amateur bodybuilders who rest 60 seconds between sets complete 15–14% less total work than those who rest 90 or 180 seconds, resulting in smaller increases in muscle size and strength.
Among amateur bodybuilders, resting 90 seconds between sets results in the same muscle growth in the thigh and biceps muscles as resting 180 seconds between sets.
Among amateur bodybuilders with at least two years of training experience, resting 90 or 180 seconds between sets during a 10-week muscle-building program leads to larger increases in muscle thickness of the thigh and biceps compared to resting 60 seconds between sets, due to higher total training volume maintained.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.