Near everyone in the wealthier parts of the world should undertake more physical activity than is presently the case. Too little exercise is harmful. That these populations are largely sedentary makes exercise look like a good intervention, one that improves long-term health considerably. Really, however, that exercise what is needed to bring human health up to par from its present low ebb. We evolved in an environment that required a great deal of physical activity, and many of our critical systems of regulation, maintenance, and stress response are tied to signals that are induced by physical activity. As a result, we corrode into age-related degeneration that much more rapidly in the absence of frequent, sustained exertion.
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.
Databases were systematically searched for peer-reviewed articles. 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 and a small effect on executive function. 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.