Abstract
OBJECTIVE: To evaluate systematic reviews of randomised controlled trials (RCTs) on the effects of exercise on general cognition, memory and executive function across all populations and ages. METHODS: Systematic reviews and meta-analyses of RCTs evaluating the effects of exercise on general cognition, memory and executive function were eligible. Data extraction and risk of bias scoring were conducted in duplicate. The A MeaSurement Tool to Assess systematic Reviews (AMSTAR-2) was used to assess the risk of bias. Effect sizes were pooled using random effects models and reported as standardised mean differences (SMD). Subgroup analyses were conducted for participant and intervention characteristics.General cognition, memory and executive function. DATA SOURCES: CINAHL, The Cochrane Library, Embase, MEDLINE via OVID, Emcare, ProQuest Central, ProQuest Nursing and Allied Health Source, PsycINFO, Scopus, Sport Discus and Web of Science. RESULTS: 133 systematic reviews (2,724 RCTs and 258 279 participants) were included. Exercise significantly improved general cognition (SMD=0.42), memory (SMD=0.26) and executive function (SMD=0.24). Memory and executive function improvements from exercise were greater for children and adolescents than for adults and older adults. Those with attention-deficit/hyperactivity disorder exhibited greater improvement in executive function than other populations. Effects were generally larger for low- and moderate-intensity interventions. Shorter interventions (1-3 months) and exergames (video games that require physical movement) had the largest effects on general cognition and memory. Findings remained statistically significant after excluding reviews rated as low and critically low quality. CONCLUSIONS: These findings provide strong evidence that exercise, even light intensity, benefits general cognition, memory and executive function across all populations, reinforcing exercise as an essential, inclusive recommendation for optimising cognitive health. TRIAL REGISTRATION NUMBER: PROSPERO ID: CRD42023468991.