The Claim

Only the arm you actually train gets a boost in its muscle cells' ability to sustain signals from the brain—your other arm doesn’t get this change.

Source: Neural determinants of the increase in muscle strength and force steadiness of the untrained limb following a 4 week unilateral training

What the research says

Supports is higher

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

Supports
37score
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.

Description
1 study reviewed
In plain English

Only the arm you actually train gets a boost in its muscle cells' ability to sustain signals from the brain—your other arm doesn’t get this change.

See the scientific wording

Persistent inward currents (estimated by ∆F) increase only in the trained limb after four weeks of unilateral resistance training, indicating a training-specific neural adaptation.

What the research says

1 study

  1. Study: Neural determinants of the increase in muscle strength and force steadiness of the untrained limb following a 4 week unilateral training

    Only the arm that did the workouts got stronger at the nerve level due to a special electrical boost called persistent inward currents — the other arm got stronger too, but for different reasons.

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

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