The Study
The role of exercise selection in regional Muscle Hypertrophy: A randomized controlled trial
This study tried to see if different exercises make different parts of your leg muscles grow bigger. They randomly picked who did which exercise, which is a good way to find out what really works. But we don’t know if the people measuring the muscles knew who did what — so we can’t be 100% sure the results are totally fair.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Two groups trained with either leg extensions or squats, same effort. One grew their thigh muscle all the way from top to bottom; the other only grew the middle part.
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 541 / 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 — if you want your thigh muscle to grow evenly, leg extensions may be better than squats for the front thigh.
- 2Leg extensions: all 3 parts of rectus femoris grew.
- 3Squats: only middle part of vastus lateralis grew.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of Sports Sciences
Year
2021
Authors
Aitor Zabaleta-Korta, Eneko Fernández-Peña, J. Torres-Unda, Arkaitz Garbisu-Hualde, J. Santos-Concejero
Related Content
Claims (5)
Isolation exercises targeting a single joint (e.g., leg extensions) produce greater hypertrophy in bi-articular muscles (e.g., rectus femoris) compared to multi-joint compound movements (e.g., squats) due to avoidance of active insufficiency.
Even if you work out the same amount and intensity, what exercise you pick can change which part of your muscle gets bigger.
Different leg exercises make different parts of your thigh muscles grow bigger—leg extensions grow all parts of one muscle, while squats mainly grow the middle part of another.
Leg extensions make the whole front of your thigh muscle grow evenly, while squats mainly make the middle part of a different thigh muscle grow.
When you work out, different parts of the same muscle can grow at different rates. Some exercises might make the far ends of your muscles grow more than the middle parts.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.