Natural History Comparison Cohort for the EXERT study Note: An Official Proposal has not been Submitted to NACC. Lead Investigator: Diane Jacobs Institution : UC San Diego E-Mail : djacobs@ucsd.edu Proposal ID : 1758 Proposal Description: The EXERT study is a Phase III randomized controlled trial examining the effects of exercise on cognitive function and AD biological markers in older adults with mild memory loss. EXERT participants are randomized to aerobic training or stretching/balance/range of motion exercise. NACC data will be used as a usual care comparison group. NACC participants will be selected to be as similar as possible to EXERT participants with respect to age, sex, race, ethnicity, educational level, and baseline MMSE using propensity score matching. Longitudinal scores from baseline through the first 12 months on the CDR.