Abstract

Approximately 14% of adults over 70 years old in the United States have dementia (Plassman et al., 2007) and another 22% have milder cognitive impairment (Plassman et al., 2008). It is expected that the number of people who develop dementia worldwide will quadruple over the next 40 years due to the aging of the baby boomer generation and longer life expectancies (Brookmeyer, Johnson, Ziegler-Graham, & Arrighi, 2007). Current medications provide some symptomatic relief but do not cure or change the course of the disease. Therefore, there is tremendous interest in identifying strategies for preventing or delaying the onset of dementia. Physical activity (PA) has emerged as one of the most promising strategies for dementia prevention (Middleton & Yaffe, 2010). In this chapter we will provide a brief overview of cognitive function, cognitive impairment, and dementia and will then summarize the evidence from longitudinal studies and randomized controlled trials (RCTs) regarding the role of physical activity in the prevention of cognitive impairment and dementia.