The Claim

Doing bicep curls one arm at a time makes your right arm stronger than doing them with both arms together, but doesn't make your biceps bigger than using both arms.

Source: Small muscle mass exercise enhances muscular adaptations? Effects of unilateral and bilateral biceps curl on maximum strength and muscle size changes.

What the research says

Supports is higher

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

Supports
61score
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.

Cause and effect
1 study reviewed
In plain English

Doing bicep curls one arm at a time makes your right arm stronger than doing them with both arms together, but doesn't make your biceps bigger than using both arms.

See the scientific wording

In untrained young women, 8 weeks of unilateral biceps curl training increases 1-repetition maximum strength in the trained right arm by 0.75 kg more than bilateral biceps curl training, but produces no greater increase in muscle thickness of the elbow flexors.

What the research says

1 study

  1. Study: Small muscle mass exercise enhances muscular adaptations? Effects of unilateral and bilateral biceps curl on maximum strength and muscle size changes.

    The study found that doing one-arm curls made the right arm 0.75 kg stronger than doing two-arm curls, but both types of training made the arm muscles grow the same amount.

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

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