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

PURPOSE 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. METHODS Children 8-12 years old completed nine cognitive tests and the multi-stage 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 socio-economic status. RESULTS 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 = .12, SE = .03, p < .001), and between cardiorespiratory fitness and (ii) grammar, spelling and vocabulary (β = .12, SE = .03, p < .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 functions domains were simultaneously taken into account. CONCLUSIONS 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, since 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 impact of cardiorespiratory fitness on language.