Corticospinal excitability and motor representation after long‐term resistance training

It is poorly understood how the central nervous system adapts to resistance training, especially after years of exposure. We compared corticospinal excitability and motor representation assessed with transcranial magnetic stimulation (TMS) between long-term trained (LRT, ≥3 years) versus untrained (UNT) males (n = 15/group). Motor-evoked potentials (MEPs) were obtained from biceps brachii during isometric elbow flexion. Stimulus-response curves created at hotspot 10% maximum voluntary torque (MVT) contractions. Maximum peak-to-peak MEP amplitude (MEPmax) was acquired 100% stimulator output intensity, whilst 25%−100% MVT produced. Maps contractions, an individualised TMS intensity eliciting 20% MEPmax hotspot. LRT had a 48% lower stimulus-response curve slope than UNT (p < .05). also 66% larger absolute map size, although used for mapping greater in (48% vs. 26% above active threshold) achieve target hotspot, due LRT. Map size strongly correlated (r 0.776, p .001). Once normalised there no difference groups .683). conclude that slope/excitability, suggesting higher neural efficiency. overwhelmingly determined by even when response matched among individuals, likely current spread intensities. Motor appears similar given size.