The Claim
In untrained men performing cable curls with matched resistance profiles, elbow range of motion, and effort, differences in volume load due to shoulder position do not result in meaningful differences in elbow flexor hypertrophy, despite higher loads being lifted in the maximally extended shoulder position.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
If you do cable curls the same way every time except for where your shoulders are, it doesn’t really matter for building arm muscle—even if you can lift heavier when your arms are stretched out.
See the scientific wording
When resistance profiles, elbow range of motion, and effort are matched in cable curls, the volume load differences between shoulder positions do not translate into meaningful differences in elbow flexor hypertrophy in untrained men, despite consistently higher loads lifted in the maximally extended shoulder position.
When you lift weights, your muscles grow not because of how heavy the weight is, but because of how long they’re under tension and how much burning sensation they feel from built-up chemicals. Even if you can lift heavier with your arm stretched out, if the total time your biceps are working and the chemical buildup inside them are the same as when you lift lighter with your arm relaxed, your muscles grow just as much.
What the research says
1 studyStudy: The effects of shoulder extension angle on elbow flexor hypertrophy in the cable curl exercise
When people did cable curls with their arms stretched out vs. relaxed — but lifted the same amount of effort and moved their elbows the same way — their biceps grew just as much either way. So, even if you can lift heavier with your arms stretched, it doesn’t help your arms get bigger.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.