Abstract des Autors

Previous transcranial magnetic stimulation (TMS) studies showed depression of motor evoked potentials (MEP) after fatiguing exercise. The purpose of the present TMS study was to evaluate changes in MEP size and central motor conduction time (CMCT) after various kinds of exercise of daily life and sports. MEP size, central and peripheral motor conduction to the primarily exercised muscle were recorded immediately before and after predominantly aerobic (climbing stairs and jogging) and anaerobic (press-ups, dumb-bell holding, 400 m-run) exercise. The strength exercise (exhausting dumb-bell holding, press-ups) resulted in a significant decrease of MEP amplitudes (-36% and -28%, resp.), running in a decrease of the MEP amplitude by 18% (p<0.07). After aerobic exercises MEP amplitudes remained unchanged. The compound motor action potentials (registered after supramaximal peripheral electrical stimulation) and the CMCT remained unchanged in all paradigms. PMCT and total motor conduction time were decreased after aerobic exercises, probably due to an increase of temperature of the legs. In conclusion, TMS is a suitable technique for objective evaluation of central fatigue, indicating that only exhaustive or strength exercises result in reduced MEPs. Verf.-Referat