Purpose: Cross-education of strength has been proposed to be greater when completed by the dominant limb in right handed humans. We investigated whether the direction of cross-education of strength and corticospinal plasticity are different following right or left limb strength training in right-handed participants.
Methods: Changes in strength, muscle thickness and indices of corticospinal plasticity were analyzed in 23 adults who were exposed to 3-weeks of either right-hand strength training (RHT) or left-hand strength training (LHT).
Results: Maximum voluntary wrist extensor strength in both the trained and untrained limb increased, irrespective of which limb was trained, with TMS revealing reduced corticospinal inhibition.
Conclusions: Cross-education of strength was not limited by which limb was trained and reduced corticospinal inhibition was not just confined to the trained limb. Critically, from a behavioral perspective, the magnitude of cross-education was not limited by which limb was trained.
Keywords: Cross-education; Directionality; Short-interval intracortical inhibition; Silent period; Strength; Transcranial magnetic stimulation.