The Claim

In recreationally trained women undergoing biceps-focused resistance training, performing preacher curls that emphasize muscle strain at long muscle lengths is associated with increased muscle thickness in the distal region of the upper arm (measured at 70% of the acromion-to-olecranon distance), with an observed effect size of Cohen’s d = 0.623 and approximately 8.8% growth from baseline, suggesting that regional hypertrophy may be influenced by exercise-specific resistance profiles.

Source: Regional Hypertrophy: The Effect of Exercises at Long and Short Muscle Lengths in Recreationally Trained Women

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
40score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Correlation
1 study reviewed
In plain English

For women who work out regularly, doing preacher curls that stretch the biceps a lot might help build more muscle in the lower part of the upper arm—about an 8.8% increase—compared to other curl types.

See the scientific wording

In recreationally trained women performing biceps-focused resistance training, preacher curls that emphasize muscle strain at long muscle lengths are associated with increased muscle thickness in the distal region of the upper arm (70% of acromion-to-olecranon distance), with a medium effect size (Cohen’s d = 0.623) and approximately 8.8% growth from baseline, suggesting regional hypertrophy may be influenced by exercise-specific resistance profiles.

What the research says

1 study
  1. Study: Regional Hypertrophy: The Effect of Exercises at Long and Short Muscle Lengths in Recreationally Trained Women

    The study found that preacher curls helped build more muscle in the lower part of the upper arm in women, which matches what the claim says.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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