Effects of aerobic exercise on cognitive function and quality of life in patients with Alzheimer’s disease: a systematic review and meta-analysis

Objectives Numerous studies have examined the effects of physical activity on cognitive performance and executive function in people with Alzheimer’s disease (AD), although findings are inconsistent and reviews focusing on specific workout and assessment tool types are insufficient. This study aimed to systematically investigate the effects of aerobic exercise on quality of life, cognitive performance, and depressive symptoms in people with AD. Design Risk of bias was assessed using the Cochrane RoB2 tool; meta-analyses used random-effects models; certainty of evidence was graded using GRADE. Data sources PubMed, Web of Science, Cochrane Library, EMBASE, Scopus, CINAHL, and CNKI through 12 March 2024. Eligibility criteria All randomized controlled trials (RCTs) using aerobic exercise as an intervention for individuals with AD. Data extraction and synthesis Two reviewers independently screened and extracted data. Standardised mean differences (SMDs) with 95% CIs were computed; Review Manager 5.4 and Stata were used for analyses, meta-regression, and sensitivity analyses. Publication bias was assessed with funnel plots, Egger’s test, and Duval and Tweedie trim-and-fill. Results Aerobic exercise enhanced cognitive function by MMSE (SMD=0.95, 95% CI 0.58 to 1.32, Z=5.06, p<0.00001) and ADAS-cog (SMD=-0.67, 95% CI -1.15 to -0.20, Z=2.77, p=0.006), and improved quality of life (SMD=0.36, 95% CI 0.08 to 0.64, Z=2.51, p=0.01), but had no statistically significant effect on depressive symptoms (SMD=-0.25, 95% CI -0.63 to 0.13, Z=1.27, p=0.21). Subgroup analyses suggested MMSE improvements with duration >16 weeks and <50 min per session; ADAS-cog improvements with duration >16 weeks and >30 min per session; and quality of life improvements with duration >16 weeks, frequency >3/week, and 30–50 min per session. Conclusion Aerobic exercise improves cognitive function and quality of life in patients with AD but does not significantly reduce depressive symptoms. Given high heterogeneity and variable study quality, conclusions require verification via more rigorous RCTs. PROSPERO registration number CRD42024526067.