Domain-specific physical activity levels and risk of dementia: a systematic review and meta-analysis

Associations between physical activity and distinct health outcomes vary by domain (eg, leisure-time, occupational, household, or commuting); however, comparable evidence on dementia risk remains scarce. We aimed to examine the associations between domain-specific physical activity and risk of all-cause dementia, Alzheimer's disease, and vascular dementia.

In this systematic review and meta-analysis, we systematically searched PubMed, CINAHL, Scopus, PsycINFO, SPORTDiscus, and Web of Science for cohort and case-control studies published between Jan 1, 2021, and May 2, 2026. We also included studies from a previous systematic review (from database inception to Oct 21, 2021) with the same search strategy and eligibility criteria. Eligible studies included adults aged 20 years or older with cognitive function assessed at baseline, physical activity measures, and at least 1 year of follow-up. Studies were appraised with the Rayyan web-based platform and summary data (relative risk [RR] and 95% CI) were extracted by up to six independent reviewers. Outcomes were all-cause dementia, Alzheimer's disease, and vascular dementia, analysed by multilevel random-effects meta-analyses. Study quality was assessed with an adapted scale. This study is registered with PROSPERO (CRD420251010899).

Among 6270 identified records, 17 studies were eligible for inclusion. Combined with 57 studies in the previous systematic review, we included 74 studies totalling 4 227 297 participants (2 230 046 [52·8%] female and 1 997 251 [47·2%] male; median age 67·3 years [IQR 56·5-74·1]). 40 (54%) studies were of moderate or high quality and 69 (93%) were conducted in high-income countries. Over a median follow-up of 10·0 years (IQR 5·1-21·3), high physical activity levels were associated with reduced risks of all-cause dementia (n=146 effect sizes; RR 0·80 [95% CI 0·75-0·86]; I²=97·4%), Alzheimer's disease (n=59; 0·79 [0·70-0·90]; I²=91·3%), and vascular dementia (n=21; 0·71 [0·58-0·87]; I²=77·5%); however, associations varied by domain. Leisure-time (k=20 studies; n=33 effect sizes; RR 0·76 [95% CI 0·65-0·88]; I²=96·6%) and household (k=1; 0·85 [0·74-0·98]) physical activity were associated with a reduced risk of all-cause dementia. By contrast, occupational (k=5; 1·20 [1·01-1·42]; I²=85·6%) and commuting (k=2; 1·10 [1·03-1·18]; I²=0·0%) physical activity were associated with an increased risk. Dose-response meta-analyses showed non-linear inverse associations for leisure-time and occupational activity. Certainty of evidence ranged from very low to low across domains.

The association between physical activity and dementia risk might be domain-specific. Public health strategies for the prevention of dementia should address equitable access to safe spaces for exercise, adequate leisure time, and mitigation strategies in occupational settings.

US National Institutes of Health, Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul; the Brazilian National Council for Scientific and Technological Development; and Department of Science and Technology of Secretariat of Science, Technology, Innovation and Health Complex of Ministry of Health of Brazil.