The Study
The effects of lengthened-partial range of motion resistance training of the limbs on arm and thigh muscle cross-sectional area
This study compared two ways of lifting weights and found that both made muscles about the same size in people who already lift regularly. But it didn’t prove one is better — just that they’re probably not very different.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
This study checked if doing partial weightlifting moves (with muscles stretched) builds muscle just as well as doing full moves.
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 571 / 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.
- 1The difference is so small it doesn't matter for real life — neither method is clearly better.
- 2After 12 weeks, both groups gained almost the same tiny amount of muscle: arm muscle changed by -0.032 units, thigh by 0 units.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Related Content
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Claims (6)
When people who already work out build muscle, they don’t get much bigger very fast, and the gains slow down over time—so to tell if one workout plan is better than another, you’d need to study a lot of people.
Doing partial-range weight exercises with a longer muscle stretch can build arm and thigh muscles just as well as doing full-range exercises, as long as you’ve been training for a while and do it for 12 weeks.
If you're already fit and lift weights, whether you do partial reps with the muscle stretched or full reps, you'll gain about the same tiny amount of strength after 12 weeks.
Scientists use tape measures and skin pinches to guess how much muscle people gain from weight training, but these methods aren’t precise enough to notice small muscle gains.
A lot of workout studies don’t have enough participants to notice small but real muscle gains in people who already lift weights, so their results might be confusing or wrong.
Doing only the bottom part of an exercise (where the muscle is stretched) can build as much muscle in your arms and legs as doing the full movement, as long as you put in the same amount of effort and work.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.