The Study
Single vs. Multi-Joint Resistance Exercises: Effects on Muscle Strength and Hypertrophy
This is a medical experiment where researchers took 29 young men who had never weight-trained before and randomly split them into two groups. One group did multi-joint exercises (like lat pull-downs) and the other did single-joint exercises (like bicep curls). After 10 weeks, both groups got stronger and their muscles got bigger - and there was no real difference between the two groups. Because the researchers randomly assigned people to groups and measured before and after, this study can show that the type of exercise probably doesn't matter for getting bigger or stronger muscles in people who haven't trained before. But since there were only 29 people and we don't know if the testers knew who was in which group, we can't be 100% sure this would be true for everyone.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Researchers split 29 untrained men into two groups - one did only lat pull-downs (multi-joint), the other did only bicep curls (single-joint). After 10 weeks, both groups gained similar amounts of muscle strength and size.
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 547 / 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 - both groups gained about 10-12% strength and 6% muscle size, which is meaningful for beginners starting resistance training
- 2Multi-joint group: 10.4% strength gain, 6.1% muscle growth.
- 3Single-joint group: 11.9% strength gain, 5.8% muscle growth.
- 4No meaningful difference between groups.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Asian Journal of Sports Medicine
Year
2015
Authors
P. Gentil, S. Soares, M. Bottaro
Related Content
Claims (9)
If young men who have never weight trained before do bicep curls twice a week for 10 weeks, their arm strength increases by about 12% on average.
When young men who haven't trained before do either multi-joint exercises (like curls) or single-joint exercises (like bicep curls) for 10 weeks, their arm muscles grow by about the same amount - there's no meaningful difference between the two types of workouts.
When young men who haven't trained before do arm exercises twice a week for about 2 months, their biceps and related muscles grow by about 6% on average.
For beginners, it doesn't really matter whether you do exercises that work one joint (like bicep curls) or multiple joints (like squats) - what matters is what equipment you have, what movements feel natural, what you enjoy, and how much time you have. The muscles will grow about the same either way.
If young men who haven't exercised before do either multi-joint exercises (like pull-ups) or single-joint exercises (like bicep curls) for 10 weeks, their arm strength increases by about the same amount - neither type of exercise is clearly better than the other.
If young men who haven't trained before do lat pull-down exercises two times per week for about 2 and a half months, their arm muscles get about 10% stronger.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.