Acute Exercise at Different Intensities Influences Corticomotor Excitability and Performance of a Ballistic Thumb...

The response to motor training is improved when preceded by a bout of aerobic exercise. However, the effect of exercise at different intensities on motor performance is not well understood. The aim of the current study was therefore to compare the neurophysiological and functional response to training with a ballistic abduction task following a single 30-min bout of low intensity continuous cycling exercise, high-intensity interval cycling exercise, or rest. In 13 healthy young subjects, transcranial magnetic stimulation (TMS) was used to assess changes in the motor evoked potential (MEP), in addition to short-interval intracortical inhibition (SICI), whereas performance was assessed by changes in thumb abduction acceleration performed over two consecutive days. High-intensity exercise resulted in increased MEP amplitude and decreased SICI immediately after exercise. Following training, the increased MEP amplitude that reflects training-dependent plasticity was not different between exercise conditions. In contrast, reductions in SICI following training on day 1 were increased following high-intensity exercise, but decreased following low-intensity exercise, whereas cortical disinhibition was abolished after training on day 2. Finally, low-intensity exercise resulted in improved ballistic motor performance on both days. Our findings provide some evidence to suggest that low-intensity aerobic cycling is beneficial for performance during subsequent ballistic training. Furthermore, the effects of exercise intensity on motor training may depend on the type of task performed.