We have discussed on recent podcasts about the concept of neuro-adaptation.
Neuro-adaptation is the initial strength gains we see in the first few weeks of corrective exercise homework, often it is more so better "coordination" of the motor patterns taught, and less so brute strength. But, it applies to strength training as well.
This strength increase is usually attributed to changes in the neural drive to muscle as a result of adaptations at the cortical or spinal level. This study investigated the change in the discharge characteristics of large populations of longitudinally tracked motor units in tibialis anterior before and after 4 weeks of strength training the ankle‐dorsiflexor muscles with isometric contractions. “
"We show for the first time that the discharge characteristics of motor units in the tibialis anterior muscle tracked across the intervention are changed by 4 weeks of strength training with isometric voluntary contractions.”
”The specific adaptations included significant increases in motor unit discharge rate, decreases in the recruitment‐threshold force of motor units and a similar input–output gain of the motor neurons.
The findings suggest that the adaptations in motor unit function may be attributable to changes in synaptic input to the motor neuron pool or to adaptations in intrinsic motor neuron properties." -Alessandro Del Vecchio et al
“These results demonstrate for the first time that the increase in muscle force after 4 weeks of strength training is the result of an increase in motor neuron output from the spinal cord to the muscle. “
The increase in muscle force after 4 weeks of strength training is mediated by adaptations in motor unit recruitment and rate coding
Alessandro Del Vecchio et al
Journal of physiology 06 February 2019