Acute Exercise Fatigue Impairs Cognitive Control: Neurophysiological Mechanisms Revealed by ERP and ERSP Analyses

This study aimed to investigate the effects of acute exhaustion exercise on cognitive control in young men, a key higher cognitive function for goal-directed behavior. Although long-term regular exercise benefits cognition, the effects of acute exhaustion exercise on cognitive control and its neural mechanisms are not fully understood. 35 male college students completed a Stroop task before and after exhaustion exercise on a cycle ergometer with incremental load. Electroencephalogram data were collected synchronously during the task. Behavioral measures (accuracy, reaction time), Event-Related Potential components (N2, P3 amplitudes and latencies), and Event-Related Spectral Perturbation (energy changes in theta, alpha, beta frequency bands) were analyzed. Results: Behavioral results showed that task accuracy only significantly decreased under the conflict condition (incongruent trials) following exhaustive exercise. ERP analysis revealed that the P3 amplitude at the anterior site (Fz) was significantly reduced post-exercise, but specifically for the incongruent condition, while the N2 amplitude demonstrated a more widespread enhancement. Time-frequency analysis found a significant decrease in alpha-band power over the parietal region after exercise. Theta and beta band activities were not significantly affected by exercise-induced fatigue. Conclusions: Acute exhaustive exercise did not impair early conflict monitoring functions (as indicated by stable N2 component and theta oscillations), but it compromised later higher-order cognitive processes related to attentional resource allocation and conflict resolution (manifested as reduced anterior P3 amplitude), accompanied by decreased efficiency in neural oscillatory activity associated with inhibitory control (reduced alpha power). This suggests that fatigue primarily affects the neural mechanisms of the "implementation" stage rather than the "monitoring" stage in the cognitive control cascade.