Mental fatigue impairs sport-specific visuomotor inhibitory control in trained table tennis players

Introduction: Mental fatigue (MF) is a psychobiological state caused by prolonged cognitive activity, which negatively impacts human performance. Research has shown that MF impairs sport-specific psychomotor performance across a myriad of sports, including table tennis (TT). Although some research already exists implying that some TT-performance outcomes are impaired by MF, sports such as TT require a more detailed overview of MF-performance decrements, such as visuomotor inhibitory control ability. Methods: Eleven trained TT players participated in this randomized counterbalanced crossover study. Participants were either required to perform a Stroop task (MF) or watch a documentary (control). The primary outcome was reaction time, assessed by using a TT-specific visuomotor task that included both simple (i.e. non-inhibitory) and inhibitory stimuli. Electroencephalography was measured throughout the trials. Secondary outcome measures include the subjective level of MF experience, motivation, rating of perceived exertion (RPE) and other traditional parameters. Results: Subjective mental fatigue was significantly higher in the MF-condition compared to the control condition (p<0.001). Nonetheless, no decrease in the Stroop performance was present. Reaction time on the visuomotor task, specifically on the inhibitory stimuli (p=0.001), was slowed down in the MFcondition compared to the control condition. RPE increased in both groups, while motivation and other secondary outcome measures remained uninfluenced. Spectral power (in upper α band and θ band) during the visuomotor task was decreased by MF, while event related potentials remained unaltered. Conclusion: The present study confirms that MF negatively impacts TT-performance, specifically inhibitory-related performance. Furthermore, this study also demonstrates, that the MF-associated decrease in TT-performance is associated with neurophysiological changes in the brain. Future studies should aim to follow-up neurophysiological changes during sport-specific tasks to create further insights in this matter. Moreover, coaches and other personnel employed in TT should be aware of MF and its effects, and possible ways to counteract it.