Effect of intense muscle exercise on motor responses to magnetic stimulation of the brain and spinal cord

The parameters of evoked motor responses of the muscles of the upper and lower extremities to magnetic stimulation of the motor zones of the cerebral cortex, spinal segments, and n. tibialis were estimated in athletes adapted to performance of different duration and intensity (short-and long-distance runners) and having different sports qualifications. It was shown that the maximum amplitude of event-related motor responses of m. gastrocnemius med. and m. soleus to transcranial magnetic stimulation of the brain was higher in the group of long-distance runners as compared with short-distance runners. Ski racers of high qualification differ from less qualified skiers in lower thresholds of excitation and a higher maximum amplitude of evoked motor responses of m. carpi radialis, m. biceps brachii, m. gastrocnemius med., and m. soleus. No statistically significant differences were found between the tested groups of subjects in the time of central motor transmission or the latent period of evoked motor responses.