Mediators of the association between physical activity and executive functions in primary school children

There is growing interest in identifying the mechanisms underpinning the effects of physical activity on executive functions (e.g. inhibitory control, cognitive flexibility) in children. Our study examined cardiorespiratory fitness, muscular fitness, and motor competence as potential mediators of this relationship. The study used baseline data from the Learning to Lead (L2L) cluster randomised controlled trial. In total, 675 children (7-11 years, 49.5% girls) completed measures of moderate-to-vigorous physical activity (MVPA), cardiorespiratory fitness, muscular fitness, motor competence, and executive functions. Structural equation modelling was used to examine the potential mediating roles of cardiorespiratory fitness, muscular fitness, and motor competence in the cross-sectional association between MVPA and executive functions. Cardiorespiratory fitness (β = 0.06, SE = 0.021, p = 0.004) partially mediated the association between MVPA and cognitive flexibility. Muscular fitness was a significant mediator of the association between MVPA and both inhibitory control (β = 0.03, SE = 0.014, p = 0.027) and cognitive flexibility (β = 0.06, SE = 0.021, p = 0.005). No significant mediated effects were found for motor competence. Our findings suggest cardiorespiratory and muscular fitness (but not motor competence) mediate the association between physical activity and executive functions in children.