Long-term exercise is associated with distinct patterns of effective connectivity in the executive control network linked to cognitive flexibility aging

Cognitive flexibility declines with age, presenting a public health challenge. While physical exercise is linked to attenuated cognitive aging, its relationship with directed information flow during task execution remains unclear. Using task-fMRI and dynamic causal modeling, we examined whether long-term exercise history is associated with differences in effective connectivity in the executive control network during task switching. Studying 101 participants stratified by age and exercise history, we found that exercising older adults exhibited reduced switch costs, performing significantly better than their sedentary counterparts and approximating the performance of young adults. Neuroimaging revealed that cognitive aging involves lower directed executive network connectivity, while long-term exercisers showed relative preservation of connectivity in specific pathways critical for conflict detection and cognitive control. We identified two distinct connectivity patterns: efficient pathways (negatively correlated with switch cost) preserved in exercisers, and inefficient compensatory pathways (positively correlated with switch cost) prominent in sedentary older adults. Mediation analyses indicated that connectivity served as a correlate of exercise-related behavioral benefits, and multivariate modeling showed effective connectivity patterns reliably distinguished groups. These findings demonstrate that long-term exercise is associated with optimized task-dependent directed information flow by preserving efficient routing while reducing compensatory pathways, providing mechanistic insights into how exercise is linked to cognitive health.