Lifestyle factors and Alzheimer-type dementia: The link between exercise and cognitive change

Background: In Alzheimer’s disease (AD) it is important to understand which factors can alter the trajectory of cognitive decline. Evidence suggests that physical activity levels are associated with global cognitive change in AD (Winchester et al., 2013). The aim of this study was to determine whether habitual physical activity specifically influences executive function change in AD over 1 year. Methods: Eighty-five participants were recruited at baseline and 45 participants were followed up 1 year later. Executive function measures (map search task, digit symbol substitution task, controlled oral word association task, verbal fluency task) and habitual physical activity measures (physical activity scale in the elderly (PASE) and handgrip strength) were taken at baseline and follow up. Individual composites were subsequently created. Additional demographic, lifestyle and neuropsychiatric measures were also taken. Results: In a structural equation model (χ (26) = 9.84, p = .998, CFI = 1.00, RMSEA = .00) a significant association was found between habitual physical activity and executive function change (β= .27, p = .04). In a cross-lagged panel analysis a significant path was found between the PASE score and executive change (β=.22, p= .01). Discussion: Habitual physical activity was associated with reduced executive function change. Whilst specific recommendations cannot be made about of the best type of physical activity to effect a reduction in executive function change, interrogation of data shows that