Full-text language: English
Garopoulou, V.1,2,6,7, Kourdoukla, E.1,3,7, Mouzakidis, C.1,3, Biblias, P.4, Loufakis, M.7, Kaloteraki, N.1,3, Kapousizis, O.5,7, Tsolaki, M.1,6
11st "Neuroscience and Neurodegeneration" M.Sc., Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
2Department of Sports Science and Coaching, New York College of Athens; Bachelor of Science (BSc Hons) in Sports Science and Coaching, University of Greater Manchester, U.K.
3Hellenic Association of Alzheimer's Disease and Related Disorders (Alzheimer Hellas), Thessaloniki, Greece
4Department of Physical Education and Sports Science, Aristotle University of Thessaloniki, Greece
5Panhellenic Institute of Neurodegenerative Diseases, Thessaloniki, Greece
6Medical School, Aristotle University of Thessaloniki, Greece; Laboratory of Neurodegenerative Diseases, CIRI, A.U.Th., Thessaloniki, Greece
7Medability Institute, Thessaloniki, Greece
Corresponding author: [email protected] & [email protected]
Abstract
Background: Dementia is a leading cause of disability in older adults, and physical inactivity is a modifiable risk factor. It is unclear whether total weekly activity volume or its temporal distribution matters more for dementia risk, and how observational findings relate to trial evidence.
Aim: To critically appraise recent evidence on physical activity volume and pattern in relation to dementia risk, to summarize the level of evidence for proposed biological mechanisms, and to outline a consensus-based exercise prescription framework, keeping these three kinds of evidence distinct.
Methods: Narrative review prepared according to the Scale for the Assessment of Narrative Review Articles (SANRA). PubMed/MEDLINE was searched for English-language publications from January 2015 to August 2026 and supplemented by reference-list screening. Cohort studies, randomized trials, meta-analyses, and consensus statements were eligible. Evidence was synthesized narratively, without pooling or formal risk-of-bias grading.
Results: In a UK Biobank accelerometer cohort (n = 91,512), more than 300 minutes/week of moderate-to-vigorous physical activity (MVPA; ≥3 metabolic equivalents) was associated with lower dementia incidence than less than 300 minutes/week, whether concentrated in 1–2 days (hazard ratio [HR] 0.73, 95% confidence interval [CI] 0.60–0.89) or regularly distributed (HR 0.79, 95% CI 0.64–0.98); the two patterns did not differ significantly (HR 0.91, 95% CI 0.70–1.18). Two further weekend-warrior analyses used overlapping UK Biobank data, and one independent cohort with self-reported activity reported a concordant association with mild dementia. Among participants below the MVPA threshold, light physical activity above 840 minutes/week was associated with lower dementia incidence, but the effect estimate is not numerically available in the source. A meta-analysis of randomized trials found a smaller effect on global cognition (standardized mean difference 0.29, 95% CI 0.17–0.41).
Limitations: The evidence is predominantly observational and dominated by one cohort, and is open to reverse causation, residual confounding, and healthy-volunteer bias. The review is narrative and based on a single database.
Conclusions: Higher physical activity volume, whether concentrated or distributed, is associated with lower dementia risk in observational data, but causality cannot be inferred and trial effects on cognition are smaller. Supervised multicomponent exercise consistent with international consensus guidance is a reasonable, low-risk recommendation for older adults; its role in dementia prevention remains to be confirmed.
Keywords: Dementia prevention; physical activity; exercise prescription; cognitive aging; healthy longevity; personalized medicine.