Aerobic physical activity to improve memory and executive function in sedentary adults without cognitive impairment: A systematic review and meta-analysis.

The worldwide population of adults ages 50 and older continues to increase and is projected to reach over 2.3 billion by 2030. Aging is the biggest risk factor for cognitive impairment and dementia. Aerobic physical activity may improve cognitive functioning, thus delaying aging-related cognitive decline. The purpose of this review was to examine the effect of aerobic physical activity on memory and executive function in sedentary adults with no known cognitive impairment. PubMed, CINAHL, Psycinfo, and Cochrane Library databases were systematically searched for peer-reviewed articles up to July 2019. Randomized controlled trials of sedentary adults, aged 50 and older, that compared an aerobic physical activity intervention to either no treatment or alternative active comparator and reported outcome measures of memory and/or executive function were included. A random effects meta-analysis was performed to examine the separate effect sizes for memory and executive function. Nine studies met inclusion criteria and contributed either memory and/or executive function effect sizes (n = 547). Results from the random effects meta-analysis suggested, by post-intervention, a large effect size for the aerobic physical activity interventions on memory (g = 0.80, 95%CI: 0.14-1.47; n = 7; p = 0.02) and a small effect on executive function (g = 0.37, 95%CI: 0.04-0.69; n = 6; p = 0.03). Aerobic physical activity may improve memory and executive function in sedentary adults without cognitive impairment. Policymakers and providers should promote aerobic physical activity in this population, and further research should investigate the most effective ways to promote aerobic physical activity in mid-life to older adults.