Do changes in cardiorespiratory fitness resulting from physical activity interventions impact academic performance and executive function in children and adolescents? A systematic review, meta-analysis, and meta-regression

Objective: The aim of this work was to conduct a systematic review, meta-analysis, and meta-regression to examine changes in cardiorespiratory fitness (CRF), academic performance (AP), and executive function (EF) of children and adolescents, in addition to the association of CFR changes with AP/EF changes, following a physical activity (PA) intervention. Method: This review was prospectively registered (PROSPERO CRD42017070845). We systematically searched Medline/PubMed (EBSCOhost), Science Direct (Elsevier ScienceDirect), Scopus (Scopus), SPORTDiscus (SPORTDiscus), Academic Search Complete, CINAHL Complete, and PsychINFO databases, with the final literature search taking place on 15th March 2018. Intervention studies that reported a pre- and a post-intervention measure of CRF and AP or EF and a control group were included. Random-effects models were used to calculate pooled effect sizes for CRF, AP, and EF (and sub-domains of EF; inhibition, working memory, and cognitive flexibility) and meta-regression was used to examine associations between moderators and outcomes. Results: A total of 13 studies (4,397 children and adolescents, aged 6-15 years old) were included. Pooled effect size (Hedges g) estimates [95% confidence intervals] were: 0.67 [95% CI = 0.08, 1.25] for CRF, -0.06 [95% CI = -0.17, 0.06] for AP, and 0.06 [95% CI = -0.02, 0.15] for EF. The effect sizes for the sub-domains of EF were as follows: 0.03 [95% CI = -0.06, 0.13] for inhibition, 0.17 [95%CI = -0.04, 0.38] for working memory, and 0.00 [95% CI = -0.16, 0.16] for cognitive flexibility. The mixed-effect meta-regression models showed that the amount of change in CRF was not significantly associated with the PA interventions effect on AP, with an effect size estimate of 0.16 [95% CI = -0.44, 0.11], or on EF, with an effect size estimate of 0.14 [95% CI = -0.14, 0.42]. Conclusions: Significant positive effects were found for CRF after PA interventions. No significant effects were found for AP or EF and CRF change was not associated with their changes. However, it should be noted that most of the PA interventions took place during time allocated to the curriculum teaching, and no negative impact on AP or EF from the additional PA was found. This suggests that schools might implement PA interventions into the curriculum with the aim of improving children’s CRF, which is associated with numerous health benefits for children in their present and future, likely without affecting educational outcomes