Chronic Exercise for Core Symptoms and Executive Functions in ADHD: A Meta-analysis

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.