The Claim

In untrained men performing cable curls with matched resistance profiles, effort, and elbow range of motion, training with the shoulder in a maximally extended position does not result in a meaningful difference in elbow flexor muscle hypertrophy compared to training with the shoulder in a neutral position over a 10-week period, with both conditions leading to approximately 6%–9% increases in muscle thickness.

Source: The effects of shoulder extension angle on elbow flexor hypertrophy in the cable curl exercise

What the research says

Supports is higher

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

Supports
60score
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

If you're new to lifting and do cable curls the same way each time, it doesn't really matter whether your arms are stretched far back or in a neutral position — your biceps will grow about the same amount after 10 weeks.

See the scientific wording

In untrained men performing cable curls with matched resistance profiles, effort, and elbow range of motion, training with the shoulder in a maximally extended position does not produce a meaningful difference in elbow flexor muscle hypertrophy compared to training with the shoulder in a neutral position over a 10-week period, with both conditions resulting in approximately 6%–9% increases in muscle thickness.

Why this might work

When the biceps are worked with the same amount of resistance, same range of motion, and same level of effort, the muscle fibers experience similar levels of stretch and force regardless of whether the shoulder is pulled back or kept relaxed. This similar force and stretch triggers the same cellular signals that tell the muscle to grow, so the muscle gets about the same bigger either way.

Verified mechanismbased on 1 study

What the research says

1 study

  1. Study: The effects of shoulder extension angle on elbow flexor hypertrophy in the cable curl exercise

    When new lifters do cable curls with the same effort and movement, it doesn’t matter if their arms are stretched back or relaxed — their biceps grow about the same either way after 10 weeks.

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

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