The Study
Effects of High-Volume Versus High-Load Resistance Training on Skeletal Muscle Growth and Molecular Adaptations
This study is like a fair race between two different ways of lifting weights — one with light weights and lots of reps, the other with heavy weights and fewer reps. It found that one way made the thigh muscle bigger, and the other made you stronger. But it only tested 15 guys who already lifted a lot, so we can’t say it works the same for everyone.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
This study tested if doing lots of light lifts or fewer heavy lifts makes your leg muscles grow bigger and stronger.
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 — 3.2% muscle growth is meaningful for athletes; 5–6 kg strength gain is practically significant for performance.
- 2Lighter weights + more reps: legs grew 3.2% bigger.
- 3Heavier weights + fewer reps: legs didn’t grow, but got 5–6 kg stronger.
- 4Lighter weights also made more non-muscle stuff in the cells.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Frontiers in Physiology
Year
2021
Authors
C. Vann, C. Sexton, Shelby C. Osburn, Morgan A Smith, Cody T Haun, Melissa N. Rumbley, Petey W. Mumford, Brian K Ferguson, Nathan T. Montgomery, Carlton D. Fox, Bradley A Ruple, James McKendry, Jonathan C. Mcleod, A. Bashir, R. Beyers, M. Brook, Kenneth Smith, P. Atherton, Darren T. Beck, J. McDonald, Kaelin C. Young, Stuart M Phillips, M. Roberts
Related Content
Claims (10)
When resistance training is performed until muscle fatigue is reached, lifting light weights and lifting heavy weights result in the same amount of muscle growth.
The more you lift each week for a specific muscle, the more it grows—but after a point, doing even more doesn't help much.
If you do lots of reps with lighter weights for six weeks, your body might make more of the non-muscle proteins inside your muscles than if you lift heavy weights with fewer reps — and this difference is pretty big.
When the number of weekly resistance training sets for a muscle group is increased from 8 to 12, muscle size increases by about 0.9% compared to the lower volume.
Doing more workout volume doesn’t necessarily make your muscles grow more—your body’s internal muscle-building signals stay about the same no matter how much you train.
If you're a young man who already trains regularly, doing more sets with lighter weights for 6 weeks can make your thigh muscle grow a little bigger — but doing fewer sets with heavier weights won't make it grow at all.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.