ABSTRACT
OBJECTIVE: To explore the effects of a 12-week aerobic exercise program with different frequencies on executive functions (EFs) in preschool children. METHOD: Four kindergartens, comprising 126 preschool children in Shanghai, were enrolled in this 12-week cluster randomized controlled trial with a 12-week follow-up period. Kindergartens were allocated to high-frequency (three times a week) or low-frequency (once a week) exercise groups using stratified block randomization. Three core sub-EFs, including inhibition, working memory, and cognitive flexibility, were assessed at baseline, post-intervention, and the 12-week follow-up. RESULTS: Compared to baseline, both groups showed significant improvements in inhibition and working memory after the intervention and at the 12-week follow-up. However, only the high-frequency exercise group demonstrated a significant improvement in cognitive flexibility after the follow-up period. Nonetheless, there were no significant differences in the core sub-functions of EFs between the two groups at the end of the intervention or the follow-up periods. CONCLUSION: A 12-week aerobic exercise of three times a week was insufficient to significantly improve EFs in preschool children compared to once a week. Future studies are needed to examine the dose-response relationship of aerobic exercise on EFs and to verify the effects of different exercise modalities on EFs in preschool children.
ABSTRACT
BACKGROUND AND OBJECTIVES: The effects of chronic exercise interventions (CEIs) on core symptoms and executive functions (EFs) of attention-deficit/hyperactivity disorder (ADHD) and how different characteristics of CEIs could modify the effect remain unclear. We synthesized the current evidence on the effects of CEIs on core symptoms and EFs in children and adolescents with ADHD. METHODS: Data sources include PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure from database inception to July 31, 2022. Study selection includes randomized controlled trials that reported on the effects of CEIs on core symptoms and/or EFs in ADHD aged 6 to 18 years. RESULTS: Twenty-two randomized controlled trials were included. CEIs had a small beneficial effect on overall core symptoms (standardized mean difference [SMD] = -0.39, 95% confidence interval [CI]: -0.64 to -0.14), as well as inattention (SMD = -0.32, 95% CI: -0.63 to -0.004) among children and adolescents with ADHD. Closed-skill exercise showed a large improvement in core symptoms (SMD = -0.83, 95% CI: -1.30 to -0.35), whereas open-skill exercise did not. Additionally, CEIs had a moderately beneficial effect on overall EFs (SMD = -0.68, 95% CI: -0.91 to -0.45) and a moderate-to-large effect on the specific domains of EFs. The pooled effects on overall core symptoms and EFs were not significantly modified by study population (children or adolescents), exercise session duration (≤50 or >50 minutes per session, median), or total exercise sessions (<24 or ≥24 sessions, median). CONCLUSIONS: CEIs have small-to-moderate beneficial effects on overall core symptoms and EFs in children and adolescents with ADHD.
