Previous studies found that exercise interventions have positive effects on executive functions of the general population. However, studies seldom target executive functions of children and adolescents with attention-deficit hyperactivity disorder (ADHD). This study aimed to synthesise empirical studies regarding the effects of exercise interventions on executive functions of children and adolescents with ADHD.
A systematic search of the relevant literature was conducted in March 2020 through six electronic databases: CINAHL Complete, Eric, MEDLINE, PsychINFO, SPORTDiscus with Full Text, and Web of Science. Randomised controlled trials/quasi-experimental designs that applied exercise interventions and assessed executive functions through neurocognitive tasks among children and adolescents with ADHD were included. Altogether, 314 studies were identified, from which 31 full texts were independently assessed by two authors for eligibility. Finally, 21 studies underwent systematic reviews and 15 were selected for meta-analysis. Data extraction procedures and risk of bias analysis were conducted by two independent authors using the Physiotherapy Evidence Database (PEDro) scale.
The findings indicated that exercise interventions improved overall executive functions of children and adolescents with ADHD (SMD = 0.611, 95% CI [0.386 to 0.836], p < 0.01). Exercise interventions had a moderate-to-large positive effect on inhibitory control (g = 0.761, 95% CI [0.376 to 1.146], p < 0.01) and cognitive flexibility (g = 0.780, 95% CI [0.331 to 1.228], p < 0.001). Likewise, during the subgroup analysis, intervention intensity and sessions of exercise (acute vs chronic) significantly moderated exercise intervention rather than intervention type.
Chronic sessions of exercise interventions with moderate intensity should be incorporated as treatment for children with ADHD to promote executive functions.