The Claim
In untrained young men, 10 weeks of cable biceps curl training performed with shoulder flexion at approximately 50° or shoulder extension at approximately 50° results in equivalent improvements in exercise-specific one-repetition maximum strength, with no meaningful difference between conditions as determined by equivalence testing (p = 0.061, 0.637), despite observed increases of 28% (Hedges’ g = 0.85) in the shoulder-flexed condition and 37% (Hedges’ g = 1.22) in the shoulder-extended condition.
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're a young guy just starting out, doing bicep curls with your arms in front of you or behind you gives about the same strength gains after 10 weeks — even if one seems to improve a bit more, the difference isn’t really meaningful.
See the scientific wording
In untrained young men, 10 weeks of cable biceps curl training with either shoulder flexion (~50°) or extension (~50°) produces equivalent improvements in exercise-specific one-repetition maximum strength, with increases of 28% (Hedges’ g = 0.85) for shoulder-flexed curls and 37% (Hedges’ g = 1.22) for shoulder-extended curls, and equivalence testing showing no meaningful difference (p = 0.061, 0.637), indicating similar strength gains despite different shoulder joint angles.
What the research says
1 studyThe study found that doing bicep curls with the shoulder bent forward or backward led to similar strength gains, just like the claim says.
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.