Cognitive decline among persons 65 years or older (hereinafter seniors) is a pressing health care issue. Effective pharmacologic treatment of mild cognitive impairment and dementia remains a major medical challenge.¹ Hence, effective primary prevention strategies for cognitive decline would greatly benefit individuals and society.

Studies supporting the notion that physical activity and exercise can help alleviate the negative impact of age on the body and the mind abound. This literature review provides an overview of important findings in this fast growing research domain. Results from cross-sectional, longitudinal, and intervention studies with healthy older adults, frail patients, and persons suffering from mild cognitive impairment and dementia are reviewed and discussed. Together these finding suggest that physical exercise is a promising nonpharmaceutical intervention to prevent age-related cognitive decline and neurodegenerative diseases.

This is a brief review of current evidence for the relationships between physical activity and exercise and the brain and cognition throughout the life span in non-pathological populations. We focus on the effects of both aerobic and resistance training and provide a brief overview of potential neurobiological mechanisms derived from non-human animal models. Whereas research has focused primarily on the benefits of aerobic exercise in youth and young adult populations, there is growing evidence that both aerobic and resistance training are important for maintaining cognitive and brain health in old age. Finally, in these contexts, we point out gaps in the literature and future directions that will help advance the field of exercise neuroscience, including more studies that explicitly examine the effect of exercise type and intensity on cognition, the brain, and clinically significant outcomes. There is also a need for human neuroimaging studies to adopt a more unified multi-modal framework and for greater interaction between human and animal models of exercise effects on brain and cognition across the life span.

The Canadian Longitudinal Study on Aging (CLSA) was established to understand and address the needs of an aging population.^1–3 Overall aims are to examine aging as a dynamic process; to investigate the inter-relationship among intrinsic and extrinsic factors from mid-life to older age; and to capture the transitions, trajectories and profiles of aging.⁴ A central objective in creating the CLSA was to provide national infrastructure and build capacity for state-of-the-art, interdisciplinary, population-based research and evidence-based decision-making.^5,6

Aim The increasing rate of all-cause dementia worldwide and the lack of effective pharmaceutical treatments emphasise the value of lifestyle approaches as prevention strategies. Emerging evidence suggests sedentary behaviour is associated with impaired cognitive function. A better understanding of this association would significantly add to our knowledge of how to best promote healthy cognitive ageing. Thus, we conducted a systematic review ascertaining the contribution of sedentary behaviour towards associated changes in cognitive function over the adult lifespan. Study design Systematic review of peer-reviewed literature examining the association of sedentary behaviour with cognition. Data sources We searched PubMed, PsycINFO, EBSCO and Web of Science, and reference lists of relevant reviews on sedentary behaviour. Two independent reviewers extracted (1) study characteristics and (2) information regarding measurement of sedentary behaviour and cognitive function. We also assessed study quality using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist. Eligibility criteria We limited search results to adults ≥40 years, observational studies published in English since 1990 and studies investigating associations between sedentary behaviour and cognitive function. Results 8 studies examined the association of sedentary behaviour with cognitive function. 6 studies reported significant negative associations between sedentary behaviour and cognitive function. 8 different measures of sedentary behaviour and 13 different measures of cognitive function were used across all eight studies. Summary Sedentary behaviour is associated with lower cognitive performance, although the attributable risk of sedentary time to all-cause dementia incidence is unclear. Our systematic review provides evidence that limiting sedentary time and concomitantly engaging in regular moderate-to-vigorous physical activity may best promote healthy cognitive ageing.