The effects of physical exercise on executive function in community-dwelling older adults living with Alzheimer's-type dementia: A systematic review

Executive function deficit is an indicator of Alzheimer's-type dementia and manifests as disruptions of attentional control, memory, cognitive flexibility, planning, and reasoning, among other cognitive problems. Physical exercise is suggested to have a protective effect on global cognition with aging. However, whether it influences executive function in people living with Alzheimer's-type dementia specifically is unknown. The current systematic review examined the efficacy of physical exercise on executive function performance in community-dwelling older adults living with Alzheimer's-type dementia. An electronic search of databases retrieved randomized and non-randomized controlled trials of community-dwelling older adults diagnosed with Alzheimer's-type dementia who completed a physical exercise intervention and who were assessed using an executive function outcome measure. Methodological quality of six studies meeting the inclusion criteria published between 2009 and 2016 was scored independently by two raters using the Physiotherapy Evidence Database and a Cochrane informed domain-based assessment of risk of bias. Trends toward improvement in executive function scores were seen across all six studies, and significant improvement was seen in four of the eligible studies. Future studies should explore the benefits of the American College of Sports Medicine recommended 150 min of physical exercise per week with select measures of executive function.