Examining the Relationship between Aerobic Fitness and Cortical Excitability

Abstract

Because of its ability to enhance cortical excitability, aerobic exercise is receiving interest as a primer for learning and rehabilitation. Previous studies show that physical activity level influences the brain s response to exercise. The purpose of this study was to examine the relationship between aerobic fitness and cortical excitability, as well as exercise-induced changes in excitability. Transcranial magnetic stimulation was used to obtain measures of excitability including the stimulus-response curve and those related to intracortical facilitatory and inhibitory networks before, immediately after, and 30 minutes after a session of aerobic exercise. We hypothesized that 1) increased fitness would be associated with increased cortical excitability at baseline; and 2) increased fitness would be associated with a larger response to the exercise, namely greater changes in cortical excitability relative to baseline. Our results did not support the hypotheses, suggesting that higher aerobic fitness may not result in greater cortical excitability.