Fluctuation of conflict and attentional processes underlying inhibitory control during high-intensity interval training.

Exercise can impair and improve inhibitory control (IC) and influence IC-related neuroelectric mechanisms during and after exercise, respectively. However, it remains unknown whether these effects coexist and fluctuate during intermittent exercise consisting of elevated physical exertion separated by recovery periods, despite this exercise modality is similar to athletic, military, and first-respond activities in applied settings. This study investigated IC fluctuation during a high-intensity interval training (HIIT) session alternating between exercise and recovery intervals. Thirty-one adults performed flanker tasks during a 33-min cycling-based HIIT and a rest control on counterbalanced days. Accuracy, response time (RT), and task-related N2/P3 event-related potentials were recorded to index IC. Compared with the control condition, overall RT decreased while accuracy declined selectively for incongruent trials during exercise intervals of HIIT. The HIIT condition showed an earlier onset of RT decrease over repeated exercise-recovery cycles, culminating in shorter RT toward ending intervals compared to control. Within the HIIT condition, N2 and P3 amplitudes reduced during exercise but rebounded during recovery intervals, while the HIIT condition resulted in suppressed P3 amplitude compared to the control condition only during exercise intervals. Although elevated exertion quickens responses at the cost of downregulated conflict processing, attention allocation, and IC accuracy, these neurocognitive changes are limited to exercise intervals and restored during recovery, with processing speed improvements continue accruing beyond exercise intervals. These findings highlight the importance of structuring cognitive tasks around recovery periods in physically demanding situations to mitigate cognitive impairment while leveraging heightened arousal for performance efficiency.