Aerobic Fitness And Executive Functions During Middle Childhood - A Complex Relationship

Growing evidence from cross-sectional and longitudinal studies suggests that aerobic fitness is positively associated with executive functions (EF) during middle childhood, yet the cognitive mechanisms underlying this relationship are poorly understood. This issue is explained, in part, due to the complexity of EF as a psychological construct with the field divided around its dimensionality and nature, as EF components (i.e., inhibition, cognitive flexibility, and working memory) are strongly related, and also share strong variance with basic processing speed. PURPOSE: By combining cognitive modeling with structural equation modeling (SEM) to disentangle basic from executive processing in EF tasks, the present study provides a more nuance understanding of the cognitive mechanisms underlying the relationship between aerobic fitness and EF. METHODS: Children 8-12 years old (n = 257) completed (i) nine cognitive tests tapping executive functions (EF), and (ii) the multi-stage fitness test (cross-sectional design). Drift diffusion modeling was used to measure ability in EF tasks, whereas SEM was used to analyze the relationship between aerobic fitness and EF, characterized as a bifactor model (i.e., EF common factor, plus specific inhibition, cognitive flexibility, and working memory factors). RESULTS: First, aerobic fitness predicted the EF common factor capturing shared variance between EF tasks (β = 0.28, p < .001), whereas the relationship with EF specific factors was weak and non-significant. Next, a latent factor capturing basic processing was added in the model, which explained most of the variance in the EF common factor (β = 0.90, p < .001). As a result, the size of effect of aerobic fitness on the EF common factor diminished remarkably, yet it remained significant (β = 0.073, p = .001). CONCLUSION: These results suggest a small effect of aerobic fitness on EF, which goes beyond and above the effect of basic processing. Furthermore, the present works provides a novel conceptualization of the complex interplay between aerobic fitness and EF, shedding light into their underlying cognitive mechanisms. Support for this research was provided by grants from (i) the Jacobs Foundation (Switzerland, CH) and (ii) the Foundation Ernest Boninchi (CH)