Evidence cerebral blood-flow regulation mediates exercise–cognition links in healthy young adults.

Healthy young adults are presumed to be in their cognitive prime, yet emerging evidence indicates that regular engagement in physical activity can still benefit their cognitive functioning. The mechanisms supporting these exercise-related cognitive benefits remain unclear, but recent research points to cerebral blood-flow (CBF) regulation as potentially important. The current study investigated the possibility that efficacy of CBF regulation underpins exercise-cognition links in this high functioning population.In 55 healthy young adults, cognitive control performance (inhibition and switching) was examined in relation to habitual physical activity, aerobic fitness, and CBF regulation (evidenced by blood-flow responsiveness to increases and decreases in carbon dioxide: hypercapnic reactivity, n = 43, and hypocapnic reactivity, n = 42).Multiple regression analyses revealed that more frequent physical activity, and to some extent better aerobic fitness, predicted both better CBF regulation and better cognitive inhibitory control. CBF regulation also predicted better cognitive inhibitory control. Moreover, mediation analyses indicated that more frequent participation in physical activity may bring about improvements in cognitive inhibitory control through improved CBF regulation.These results provide novel insight into the cognitive and cerebrovascular benefits that may be gained with regular engagement in physical activity, even in a high-functioning population. Moreover, they point to better CBF regulation as a specific mechanism that may drive physical activity-related cognitive benefits, which converges with recent data in older women (Brown et al., 2010).