Impact of maximal physical exertion on interference control and electrocortical activity in well-trained persons

PURPOSE: The aim of this study was to examine the impact of a maximal physical load on cognitive control in twelve well-trained males focusing on the time course of changes in a 15 min post-exercise interval. METHODS: Prior to and three times after an incremental cycle ergometer task until exhaustion, behavioural performance and neurophysiological correlates using N2 and P3 event-related potentials (ERPs) were assessed during the execution of a modified flanker task. These data were compared to a control condition following the same protocol, however, without physical load between pre-test and post-tests. RESULTS: Regardless of compatibility (congruent, incongruent), behavioural findings revealed a significant interaction of Condition × Time with shorter reaction times in the post-exercise blocks as compared to the control condition. Neuroelectric measures demonstrated exercise induced effects of a reduced central N2 amplitude and shorter parietal P3 latency in the time course of post-exercise flanker blocks as compared to rest. CONCLUSIONS: It is concluded that a state of maximal physical exhaustion facilitates information processing speed in a cognitive control task in well-trained persons. This effect persists even after a recovery period of 15 min. The current findings contribute to a deeper understanding of the neuronal mechanisms of interference control following maximal physical load, suggesting a reduced conflict monitoring as indicated by a reduced N2 amplitude and an increased stimulus classification speed as reflected by P3 latency. The flanker task, however, might have been too simple to elicit monitoring conflicts on the behavioural level.