Moving the body or watching the screen: 20-minute exercise modulates brain activity and enhances cognitive performance in younger and older male adults

Acute exercise (AE) has been shown to enhance cognitive and mental functioning, yet the underlying neural dynamics across age groups remain unclear. This study examined how a 20-min bout of moderate-intensity AE modulates behavioral and neural responses supporting cognitive control. Fifty-one healthy males (28 younger, 23 older adults) completed both AE (treadmill, 60–70% heart-rate reserve) and control (video watching) conditions in a counterbalanced within-subject design. EEG was recorded during a Stroop color–word task following each condition. AE shortened reaction times without reducing accuracy, indicating greater processing efficiency. Event-related potential analyses revealed reduced N1/N2 amplitudes, while time–frequency results showed stronger frontal alpha desynchronization and increased theta–beta modulations. These effects reflect enhanced attentional allocation and cortical engagement. Collectively, findings suggest that even a single AE session can transiently optimize neural efficiency through a dual-phase mechanism—reducing early sensory and conflict-monitoring demands while facilitating later attentional and evaluative processes—highlighting exercise as a brief yet effective means to promote adaptive mental functioning across the adult lifespan. • A 20-min bout of moderate-intensity aerobic exercise engages a dual-phase neural mechanism supporting inhibitory control. • Exercise attenuates early sensory and conflict-monitoring demands while enhancing later cognitive control and motor preparation. • These findings indicate that transient physical activity optimizes neural efficiency across age groups through temporally distinct processes.