Author(s): BADARIOTTI, J., LOCKHART, T.1, MOORE, R.1, STOCKER, B.1, CIRIA, L.2,3, ALAMEDA, C.2,3, AVANCINI, C.3, MAYES, H.1, COSTELLO, J.1, Institution: UNIVERSITY OF PORTSMOUTH, Country: UNITED KINGDOM, Abstract-ID: 1579

INTRODUCTION:
Acute aerobic exercise has been shown to enhance executive function, whereas task performance has been shown to be sensitive to exercise intensity (1). Evidence from electroencephalography (EEG) suggests that acute exercise alters task-related cortical activity during executive tasks, although direct comparisons of exercise intensity remain limited, particularly for working memory paradigms (2). Therefore, this study examined the effects of light- and moderate-intensity aerobic exercise (cycling) on short-term working memory performance and stimulus-locked EEG activity.
METHODS:
In a randomised, counterbalanced, within-participant crossover design, fourteen healthy adults (9 females) completed two experimental trials. In each trial, participants performed a numerical 2-back task before, and after, 20-min of cycling exercise at either light intensity (30–40% heart rate reserve [HRR]; Borg RPE 9–11) or moderate intensity (40–59% HRR; Borg RPE 12–13). Reaction time (RT), accuracy, and throughput were recorded. EEG was collected during task performance and transformed using current source density (CSD) interpolation. Time domain EEG was then extracted from the CSD transformed data. Cognitive performance was assessed using 2 (Intensity: light, moderate) × 2 (Time: pre, post) repeated-measures ANOVAs. Event-related potential (ERP) amplitude differences were examined using an exploratory cluster-based permutation analysis to identify potential event related components.
RESULTS:
RT decreased following exercise (main effect of Time: F(1,13)=17.85, p<0.001): light-intensity 33.81 ± 8.9 ms, and moderate-intensity, 25.29 ± 9.4 ms, while accuracy remained unchanged (p range p = 0.636 to p = 1). Throughput improved post-exercise (F(1,13)=15.40, p=.002). No main effects for intensity or interaction effects were observed for cognitive performance measures (p range p = 0.05 to p = 1). ERP analyses revealed significant clusters differentiating light- and moderate-intensity exercise in time windows corresponding to P300 components. Light-intensity exercise identified one significant negative cluster, indicating a reduction in P300 amplitude in the right frontal and frontocentral electrodes. While moderate-intensity exercise identified four significant positive clusters localized over parietal and parieto-occipital regions, indicating an increase in P300 amplitude. These results suggest an intensity-dependent modulation of task-related cortical activity.
CONCLUSION:
Acute aerobic exercise improved short-term working memory reaction time and throughput without compromising accuracy, independent of exercise intensity. Although cognitive performance outcomes were comparable across intensities, ERP findings suggest that exercise intensity influences cortical processing during working memory performance. These findings support the utility of EEG for examining intensity-related neural effects of acute exercise.

References:
[1] Chang et al., 2025 [2] Kao et al., 2020