%0 Journal Article %T Dynamic Associations of Change in Physical Activity and Change in Cognitive Function: Coordinated Analyses of Four Longitudinal Studies %A Magnus Lindwall %A Cynthia R. Cimino %A Laura E. Gibbons %A Meghan B. Mitchell %A Andreana Benitez %A Cassandra L. Brown %A Robert F. Kennison %A Steven D. Shirk %A Alireza Atri %A Annie Robitaille %A Stuart W. S. MacDonald %A Elizabeth M. Zelinski %A Sherry L. Willis %A K. Warner Schaie %A Boo Johansson %A Marcus Praetorius %A Roger A. Dixon %A Dan M. Mungas %A Scott M. Hofer %A Andrea M. Piccinin %J Journal of Aging Research %D 2012 %I Hindawi Publishing Corporation %R 10.1155/2012/493598 %X The present study used a coordinated analyses approach to examine the association of physical activity and cognitive change in four longitudinal studies. A series of multilevel growth models with physical activity included both as a fixed (between-person) and time-varying (within-person) predictor of four domains of cognitive function (reasoning, memory, fluency, and semantic knowledge) was used. Baseline physical activity predicted fluency, reasoning and memory in two studies. However, there was a consistent pattern of positive relationships between time-specific changes in physical activity and time-specific changes in cognition, controlling for expected linear trajectories over time, across all four studies. This pattern was most evident for the domains of reasoning and fluency. 1. Introduction Previous research has clearly demonstrated that cognitive change in old age does not occur in a homogenous manner for all individuals [1¨C3]. A number of predictors of cognitive change in old age have been identified, such as education, hypertension, objective indices of health and cardiovascular disease, and apolipoprotein E [4]. Regular engagement in different types of activities may also influence cognitive change. More specifically, according to the Ħ°use it or lose itĦħ hypothesis [5], regular engagement in different activities may buffer age-related decline in cognitive functioning. A number of studies have found that general lifestyle activity engagement (often operationalized as the combination of intellectual, social, and physical activities) is associated with cognitive change [6¨C8] and that decline in activity in older age is associated with decline in cognitive functioning. In addition to general activity, other studies have specifically targeted the association of physical activity with cognitive change. Indeed, a growing body of the literature highlights the potential benefits of physical activity on the structure and function of the brain [9, 10]. The first line of evidence for the relationship between physical activity and cognition comes from a number of cross-sectional studies demonstrating that physically active older adults have higher cognitive performance and functioning compared with less active older adults [11, 12]. However, the evidence derived from these cross-sectional studies is limited, as it is not. possible to draw conclusions in terms of more complex associations of change. Stronger evidence may be found in longitudinal studies. Longitudinal studies may be viewed as the second line of evidence, offering valuable information on the %U http://www.hindawi.com/journals/jar/2012/493598/