The effect of a single bout of moderate aerobic exercise on prefrontal activation during a cognitive-motor task in male university students: The moderating role of cardiorespiratory fitness

OBJECTIVE: This study examined whether cardiorespiratory fitness (CRF) is associated with differences in behavioral performance and prefrontal oxygenated hemoglobin (Oxy-Hb) responses during a cognitive-motor dual task in male university students. METHODS: Forty male university students were classified into high-CRF and low-CRF groups based on maximal oxygen uptake (VO₂max). Participants completed a single 25-min bout of moderate-intensity cycling. Before and after this exercise bout, they performed a cycling-based dual task that combined steady-state cycling with Serial-7 subtraction. During the dual-task assessments, reaction time, accuracy, and task-evoked prefrontal Oxy-Hb responses were recorded using functional near-infrared spectroscopy. RESULTS: Compared with the low-CRF group, the high-CRF group showed better baseline dual-task accuracy and higher baseline Oxy-Hb in the left dorsolateral prefrontal cortex. Following exercise, the high-CRF group demonstrated greater improvement in reaction time. Group differences in exercise-related changes in Oxy-Hb were also observed in the right dorsolateral prefrontal cortex and frontopolar area, although only the right dorsolateral prefrontal cortex effect remained significant after correction for multiple comparisons. Regression analyses further showed that VO₂max significantly predicted post-exercise reaction time, accuracy, and Oxy-Hb responses in selected prefrontal regions. CONCLUSION: CRF was associated with both baseline dual-task performance and post-exercise changes in behavioral performance and prefrontal Oxy-Hb responses. These findings are consistent with the view that higher cardiorespiratory fitness may be linked to more favorable neurocognitive responses following acute moderate-intensity exercise.