Cognitive decline is a common feature of aging. Physical activity is a modifiable lifestyle factor that has been identified as positively impacting cognitive health of older adults. Here, we review the current evidence from epidemiological (i.e., longitudinal cohort) and intervention studies on the role of physical activity and exercise in promoting cognitive health in older adults both with and without cognitive impairment. We highlight some of the potential underlying mechanisms and discuss some of the potential modifying factors, including exercise type and target population, by reviewing recent converging behavioral, neuroimaging, and biomarker evidence linking physical activity with cognitive health. We conclude with limitations and future directions for this rapidly expanding line of research.
Teresa Liu-Ambrose and John R. Best
Ryan S. Falck, Glenn J. Landry, Keith Brazendale, and Teresa Liu-Ambrose
Evidence suggests sleep and physical activity (PA) are associated with each other and dementia risk. Thus, identifying reliable methods to quantify sleep and PA concurrently in older adults is important. The MotionWatch 8© (MW8) wrist-worn actigraph provides reliable estimates of sleep quality via 14 days of measurement; however, the number of days needed to monitor PA by MW8 for reliable estimates is unknown. Thus, we investigated the number of days of MW8 wear required to assess PA in older adults. Ninety-five adults aged > 55 years wore MW8 for ≥ 14 days. Spearman-Brown analyses indicated the number of monitoring days needed for an ICC = 0.95 was 6–7 days for sedentary activity, 9–10 days for light activity, and 7–8 days for moderate-to-vigorous PA. These results indicate 14 days of MW8 monitoring provides reliable estimates for both sleep and PA. Thus, MW8 is ideal for future investigations requiring concurrent measures of both sleep quality and PA.