Objective To synthesise randomised controlled trials (RCTs) regarding the effects of chronic exercise interventions on different domain-specific executive functions (EFs) among children and adolescents.
Design Systematic review with meta-analysis.
Data sources PsycINFO, PubMed, SPORTDiscus, Academic Search Premier, Embase and Web of Science were searched.
Eligibility criteria for selecting studies RCTs or cluster RCT design, which employ chronic exercise interventions and target healthy children (age 6–12 years) and adolescents (age 13–17 years). We defined chronic exercise as physical activity (PA) which consists of multiple exercise sessions per week and lasts for an extended period of time (typically over 6 weeks).
Results We included 19 studies, with a total of 5038 participants. The results showed that chronic exercise interventions improved overall EFs (standardised mean difference (SMD)=0.20, 95% CI 0.09 to 0.30, p<0.05) and inhibitory control (SMD=0.26, 95% CI 0.08 to 0.45, P<0.05). In meta regression, higher body mass index was associated with greater improvements in overall EFs performance (β=0.03, 95% CI 0.0002 to 0.06, p<0.05), whereas age and exercise duration were not. In subgroup analysis by intervention modality, sports and PA programme (SMD=0.21, 95% CI 0.12 to 0.31, p<0.05) and curricular PA (SMD=0.39, 95% CI 0.08 to 0.69, p<0.05) improved overall EFs performance, but integrated PA did not (SMD=0.02, 95% CI −0.05 to 0.09, p>0.05). Interventions with a session length < 90 minutes improved overall EFs performance (SMD=0.24, 95%CI 0.10 to 0.39, p=0.02), but session length ≥ 90 minutes did not (SMD=0.05, 95%CI -0.03 to 0.14). No other moderator was found to have an effect.
Conclusions Despite small effect sizes, chronic exercise interventions, implemented in curricular or sports and PA programme settings, might be a promising way to promote multiple aspects of executive functions, especially inhibitory control.
Contributors YX: contributed to the design of the study, literature search, data screening and extraction, conducted all statistical analyses and wrote the first draft of the manuscript. YY: contributed to the literature search, data screening and extraction, statistical analyses, and critically reviewed and revised the manuscript. TH: contributed to the design of the study, data screening and data interpretation, critically reviewed and revised the manuscript. All authors approved the submission.
Funding TH was supported by Shanghai Pujiang Program (16PJC052) and the research project from General Administration of Sport of China (2017B044).