Abstract
Ageing is associated with declines in key cognitive domains and increased risk of dementia, including Alzheimer's disease (AD). While pharmacological treatments are emerging to treat dementia pathologies, their access remains limited, and growing evidence suggests physical activity and structured exercise may support cognitive health in older adulthood. Observational studies indicate that higher habitual physical activity levels are associated with better cognitive performance and slower decline. Randomized controlled trials have shown that both aerobic and resistance exercise can improve memory and executive function in both cognitively unimpaired older adults and those with mild cognitive impairment. Several mechanistic pathways by which exercise can enhance cognitive health in older adults have been identified, including increases in neurotrophic factors, alterations to dementia-related pathologies, improvements in vascular and metabolic health, and reductions in neuroinflammation. Despite promising findings, inconsistencies remain regarding optimal exercise modalities and doses, particularly in diverse populations. Addressing these gaps through high-quality and inclusive research will be critical in the translation of exercise into scalable interventions to promote cognitive health and mitigate dementia risk in ageing populations.