Aerobic fitness and academic achievement: disentangling the indirect role of executive functions and intelligence

Research in children points to aerobic fitness as a source of individual differences in academic achievement. By examining the indirect effects of executive functions (EF) and intelligence on the relationship between aerobic fitness and academic achievement, the present study provides novel insight about the cognitive mechanisms underlying this relationship. 218 children (8-10 years) completed the following assessments: (i) a VO2max test to assess aerobic fitness; (ii) four tasks tapping components of EF (i.e., inhibition and cognitive flexibility); (iii) sub-tests of the Kaufman Brief Intelligence Test to assess fluid and crystallized intelligence; and (iv) sub-tests of arithmetic, spelling, and reading achievement (WRAT 3rd edition). Structural equation modeling (SEM) was conducted to examine the indirect role of EF and intelligence on the relationship between aerobic fitness and sub-domains of academic achievement. Covariate analyses included age, pubertal timing, and socio-economic status. Preliminary analysis via linear regression showed a direct effect of aerobic fitness on arithmetic achievement, whereas no effect was observed on spelling and reading achievement. Importantly, multiple mediation SEM revealed the direct effect of aerobic fitness on arithmetic achievement disappeared after accounting for the indirect effects of EF, whereas intelligence did not contribute significantly on this complex mediation process. Moreover, among EF components, cognitive flexibility, but not inhibition, was observed to mediate between aerobic fitness and arithmetic achievement. Unpacking which components of EF and intelligence affect the link between aerobic fitness and academic achievement, holds the promise of better understanding the heterogeneity still present in the literature.