Training one arm makes both arms stronger
Neural determinants of the increase in muscle strength and force steadiness of the untrained limb following a 4 week unilateral training
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
The untrained limb improved force steadiness and strength without any physical training.
Common belief is that strength gains require muscle loading—this shows neural adaptations alone can produce measurable gains in strength and control.
Practical Takeaways
If you injure one arm, train the other—it may help maintain some strength and control in the injured side.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
The untrained limb improved force steadiness and strength without any physical training.
Common belief is that strength gains require muscle loading—this shows neural adaptations alone can produce measurable gains in strength and control.
Practical Takeaways
If you injure one arm, train the other—it may help maintain some strength and control in the injured side.
Publication
Journal
The Journal of Physiology
Year
2025
Authors
E. Lecce, P. Amoruso, A. D. Vecchio, A. Casolo, F. Felici, D. Farina, I. Bazzucchi
Related Content
Claims (6)
Unilateral resistance exercises can increase neural drive and muscle fiber recruitment compared to bilateral exercises due to reduced neuromuscular inhibition during single-limb contractions.
Working out one arm can make the other arm stronger and more steady, even if you didn't touch it—your brain is learning to control it better.
After training one arm, the other arm gets stronger because its motor neurons become easier to activate and receive more synchronized signals from the brain.
When your brain sends more coordinated signals to your muscles and less random noise, your movements become smoother and more controlled—even in muscles you didn’t train.
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.