Why your muscles get stronger before they get bigger
The increase in muscle force after 4 weeks of strength training is mediated by adaptations in motor unit recruitment and rate coding
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Your muscles get stronger faster than they grow because your nerves learn to fire better. This study found that after 4 weeks of ankle exercises, nerves sent stronger signals to the muscle without making the muscle bigger.
Surprising Findings
Motor unit discharge rates increased during steady contractions (35–70% MVC) but NOT at the start or end of movement.
People assume training makes muscles fire faster when starting or stopping—this shows adaptation is specific to the ‘holding’ phase, not initiation.
Practical Takeaways
Do 3–5 sets of 10-second isometric ankle dorsiflexion holds (pull toes toward shin against resistance) 4x/week to boost neural efficiency for running, jumping, or rehab.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Your muscles get stronger faster than they grow because your nerves learn to fire better. This study found that after 4 weeks of ankle exercises, nerves sent stronger signals to the muscle without making the muscle bigger.
Surprising Findings
Motor unit discharge rates increased during steady contractions (35–70% MVC) but NOT at the start or end of movement.
People assume training makes muscles fire faster when starting or stopping—this shows adaptation is specific to the ‘holding’ phase, not initiation.
Practical Takeaways
Do 3–5 sets of 10-second isometric ankle dorsiflexion holds (pull toes toward shin against resistance) 4x/week to boost neural efficiency for running, jumping, or rehab.
Publication
Journal
The Journal of Physiology
Year
2019
Authors
A. Del Vecchio, A. Casolo, F. Negro, Matteo Scorcelletti, I. Bazzucchi, R. Enoka, F. Felici, D. Farina
Related Content
Claims (6)
Strength expression is highly movement-specific, but in untrained individuals, neuromuscular adaptation from compound movements can produce greater strength gains in target movements than direct practice due to enhanced motor unit recruitment and coordination.
Even though your nerves fire faster after training, they still respond to how hard you’re trying at the same rate—your brain’s control system didn’t get more sensitive.
Your muscles don’t fire faster when you start or stop pushing—only when you’re holding a steady push—after four weeks of strength training.
After four weeks of strong, held ankle lifts, your nerve signals to the muscle get faster during moderate efforts, making your muscle stronger without needing more muscle mass.
After four weeks of doing strong, held ankle lifts, your muscles start firing earlier when you try to push, so you can generate more force without your muscles getting bigger.