Effect of Physical Activity on Cognitive Function in Older Adults at Risk for Alzheimer Disease

To determine whether physical activity reduces the rate of cognitive decline among older adults at risk. DESIGN AND SETTING: Randomized controlled trial of a 24-week physical activity intervention conducted between 2004 and 2007 in metropolitan Perth, Western Australia. Assessors of cognitive function were blinded to group membership.

We recruited volunteers who reported memory problems but did not meet criteria for dementia. Three hundred eleven individuals aged 50 years or older were screened for eligibility, 89 were not eligible, and 52 refused to participate. A total of 170 participants were randomized and 138 participants completed the 18-month assessment. INTERVENTION: Participants were randomly allocated to an education and usual care group or to a 24-week home-based program of physical activity. MAIN OUTCOME MEASURE: Change in Alzheimer Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) scores (possible range, 0-70) over 18 months.