Transient and selective effects of acute exercise intensity on response inhibition: an EEG study

Acute aerobic exercise can transiently influence cognitive control, but how exercise intensity and recovery timing shape response inhibition and its neural correlates remains insufficiently understood. This EEG study tested how different exercise intensities modulate response inhibition, behavioral performance, and event-related potentials (ERPs) across pre-exercise, during exercise, and two recovery phases. Twenty-one healthy young adults (6 females, 15 males) participated and self-selected an exercise-intensity level at registration, exercising at a low, moderate or high intensity based on heart rate reserve. Participants performed a stop-signal task (SST) in four experimental conditions: pre-exercise (control), during exercise (exercise), immediately post-exercise (recovery_1), and after heart rate had returned to near resting levels (recovery_2). Behavioral performance indices, including reaction times and accuracy measures, and ERP components (P2, N2, and P3) were assessed. Behavioral analyses revealed significantly reduced reaction times during the exercise condition compared to the control condition, particularly in the high-intensity exercise group. These improvements were transient, with performance returning to baseline or slowing during the recovery phases. ERP analyses showed selective, phase-dependent modulation. Specifically, the N2 amplitude during go trials was significantly reduced during exercise, indicating altered engagement of go-related control processes rather than uniquely implying improved efficiency, while the N2 amplitude during stop trials remained unchanged. Additionally, the P3 amplitude during unsuccessful stop trials showed a modest increase in the immediate post-exercise recovery period, suggesting a transient modulation of evaluation/monitoring processes. Overall, these findings indicate phase-specific exercise effects in a response inhibition task, with facilitation of response execution and stopping during exercise flanked by recovery-phase ERP modulations. By systematically characterizing performance and ERPs across control, exercise, and recovery periods with EEG recorded during exercise with different intensities, we found that in-exercise behavioral gains were most pronounced at higher intensities, whereas persistence after exercise was limited. Overall, acute exercise temporarily enhances response execution and stopping efficiency during exercise-especially at higher intensities-but these effects do not appear to continue into short post-exercise recovery windows in the present protocol.