In one eight-week study of 21 trained men, a group that rested 3 minutes between sets gained more in 1RM squat and bench press than a group that rested 1 minute. Reviews of the wider literature add qualifications, and how they differ from that study is the subject of this guide. Only the PubMed abstracts of four papers were read, on 1 November 2026. Full texts were not read, so nothing beyond the abstracts is reported, and the figures below are the authors’ own.
The four papers at a glance
- Schoenfeld and colleagues, Journal of Strength and Conditioning Research, 2016: a controlled study in which 21 young resistance-trained men were randomly assigned to 1-minute or 3-minute rests, with all other training variables held constant.
- Grgic, Schoenfeld and colleagues, Sports Medicine, 2018: a systematic review of rest intervals and muscular strength, covering 23 studies and 491 participants (413 males and 78 females).
- Grgic and colleagues, European Journal of Sport Science, 2017: a systematic review of short (60 seconds or less) against long (more than 60 seconds) inter-set rests and muscle size, covering six studies.
- Singer and colleagues, Frontiers in Sports and Active Living, 2024: a systematic review with Bayesian meta-analysis of inter-set rest and muscle size, covering nine randomised studies and 19 measurements.
Strength: what the 2018 review concluded
The 2018 review starts from a gap: recommendations on rest for strength gains are largely inferred from studies of acute effects, and it is uncertain whether they carry over to long-term adaptation. Its aim was to gather the studies that measured chronic strength adaptations with different rest intervals.
Its conclusion has three parts. Robust gains in muscular strength can be achieved even with short rests of under 60 seconds. Longer rests of more than 2 minutes seem to be required to maximise strength gains in resistance-trained individuals. For untrained individuals, short to moderate rests of 60 to 120 seconds seem sufficient. The authors rated all included studies as good to moderate in methodological quality.
The 2016 controlled study points the same way for trained men. After eight weeks of three total-body workouts a week, each made up of 3 sets of 8 to 12 repetition maximum on 7 exercises, maximal strength in both the 1RM squat and bench press was significantly greater in the 3-minute group than in the 1-minute group.
Muscle size: a less settled picture
The 2017 review described the findings on short against long rests as equivocal, and concluded that both short and long rests may be useful for gaining muscle size. It reported that novel findings in trained participants, using measures sensitive enough to detect change, suggest a possible advantage for long rests, and it called for further research because few studies had similar designs.
In the 2016 study, muscle thickness was significantly greater in the 3-minute group in the anterior thigh, with a trend, at p = 0.06, in the triceps. Both groups improved local upper-body muscle endurance, and the difference between them was not significant.
The 2024 meta-analysis found substantial overlap between the effect sizes for short and longer rests, and substantial heterogeneity in results. For the arm and thigh, its central estimates tended to favour longer rests; for the whole body, the estimate was close to zero and marginally favoured shorter rests. The credible intervals reported in the abstract for the arm, thigh and whole body all span zero. The authors conclude that results suggest a small hypertrophic benefit to rests of more than 60 seconds, perhaps mediated by reductions in volume load, but that no appreciable difference was detected when resting more than 90 seconds between sets.
Reading “perhaps mediated by volume load”
The 2024 authors offer a possible reason rather than a finding. They say the small benefit of longer rests is perhaps mediated by reductions in volume load, and that this is consistent with evidence that detrimental effects on volume load tend to plateau beyond 90 seconds. A sub-analysis of end-point data found that training to failure, or stopping short of it, did not meaningfully change how rest length related to muscle size.
What the abstracts leave open
- The samples differ. The 2016 study involved young resistance-trained men; the 2018 review had 413 male and 78 female participants and gives separate conclusions for trained and untrained individuals; the 2024 analysis covers healthy adults.
- The measures differ. Strength reviews and muscle-size reviews use different outcomes, and the 2024 paper pools arm, thigh and whole-body measurements that do not all point the same way.
- Equipment is not the focus. The abstracts read do not describe training with adjustable dumbbells or kettlebells, and the 2016 study tested strength with the squat and bench press.
- Pooled figures hide spread. The 2024 authors flag substantial heterogeneity, and the 2017 authors flag too few comparable studies.
The bottom line
For strength, the 2018 review concludes that short rests can still produce robust gains, while rests of more than 2 minutes seem to be needed to maximise gains in resistance-trained people. For muscle size, the 2017 review calls both short and long rests useful, and the 2024 meta-analysis reports a small benefit above 60 seconds with no clear extra benefit above 90 seconds. The abstracts do not address kettlebell or adjustable dumbbell training specifically, and the authors themselves describe the muscle-size evidence as varied.
Sources
- Longer interset rest periods enhance muscle strength and hypertrophy in resistance-trained men, Schoenfeld and colleagues, Journal of Strength and Conditioning Research, 2016, abstract, read 1 November 2026 (pubmed.ncbi.nlm.nih.gov)
- Effects of rest interval duration in resistance training on measures of muscular strength: a systematic review, Sports Medicine, 2018, abstract, read 1 November 2026 (pubmed.ncbi.nlm.nih.gov)
- The effects of short versus long inter-set rest intervals in resistance training on measures of muscle hypertrophy: a systematic review, European Journal of Sport Science, 2017, abstract, read 1 November 2026 (pubmed.ncbi.nlm.nih.gov)
- Give it a rest: a systematic review with Bayesian meta-analysis on the effect of inter-set rest interval duration on muscle hypertrophy, Frontiers in Sports and Active Living, 2024, abstract, read 1 November 2026 (pubmed.ncbi.nlm.nih.gov)
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