The Indirect Role of Executive Functions on the Relationship between Cardiorespiratory Fitness and School Grades.

Abstract

The aim of this study was to investigate the indirect effects of cardiorespiratory fitness on scholastic performance through executive functions. More precisely, we examined the contribution of the different domains of executive functions, and whether this relationship was specific to certain school topics. Children 8-12 yr old completed nine cognitive tests and the multistage fitness test. Structural equation modeling techniques were used to analyze the role of different domains of executive functions (inhibition, working memory, cognitive flexibility, and a common factor to all tasks) in the relationship between cardiorespiratory fitness and school grades in three domains: (i) mathematics; (ii) grammar, spelling, and vocabulary; and (iii) text comprehension and expression. Covariate analyses included age and socioeconomic status. The results of this study showed that an indirect effect of the various domains of executive functions explained, in part, the relationship between cardiorespiratory fitness and (i) mathematics (β = 0.12, SE = 0.03, P < 0.001), and between cardiorespiratory fitness and (ii) grammar, spelling, and vocabulary (β = 0.12, SE = 0.03, P < 0.001). No relationship between cardiorespiratory fitness and (iii) text comprehension and expression was observed. Although executive functions correlated with school grades, cognitive flexibility drove the indirect effect when all executive function domains were simultaneously taken into account. These results show the role that executive functions play in understanding the relationship between cardiorespiratory fitness and scholastic performance. Importantly, not all executive function domains contributed equally because cognitive flexibility played a leading role in this wide age range. Furthermore, the relationship between cardiorespiratory fitness and scholastic performance was strongest for mathematics and for low-level language topics but nonsignificant for higher-level language topics, providing a more modulated view of the effect of cardiorespiratory fitness on language.