Exercise in Adults With Mild Memory Problems

Overall Study Design: The EXERT trial was a multicenter phase 3 randomized, single-blind study that examined the effects of aerobic exercise on cognition, functional status, whole and regional cerebral blood flow, and cerebrospinal fluid biomarkers of Alzheimer's disease in approximately 300 adults with amnestic MCI. EXERT included an 18-month behavioral intervention trial, with a 12-month supervised exercise intervention phase with its primary endpoints, followed by a 6-month unsupervised exercised phase. Subject Populations and Group Assignments: The study population included male and female subjects aged 65 to 89 diagnosed with test scores and clinical ratings consistent with amnestic Mild Cognitive Impairment (MCI). Assignment to study groups: involved randomization to either treatment or active control, and study staff performing assessments were blinded to intervention assignment to maintain the single-blind structure of the trial. Participants were to complete EXERT interventions at participating YMCAs located near the selected clinic sites across the U.S. The YMCA provided 18-month memberships at no cost to participants. In the first 12 months, a study-certified YMCA Trainer supervised all participants for the first 8 exercise sessions completed (weeks 1 and 2), and for 2 of 4 weekly sessions thereafter through Month 12. At Month 12, participants transitioned to independent exercise and were instructed to continue their assigned exercise programs for the final 6 months of the study without supervision. To encourage adherence and optimize cost efficiency, Trainers provided supervision to small groups of participants (2-4 individuals) randomized to the same intervention whenever possible. Compliance was evaluated using multiple mechanisms including heart rate monitoring, participant ratings of perceived exertion, entries in participants' Physical Activity Logs, Trainer assessment of effort, and weekly data review by the YMCA-Project Manager (Y-PM) and the Intervention Oversight Team (includes the Project Directors, Wake Forest team of exercise trial specialists, and Y-USA). These mechanisms provided multiple and regular opportunities to discuss participant progress, identify and resolve barriers, and encourage high levels of adherence to study protocols. The Intervention Oversight Team had the necessary expertise to successfully accomplish this objective in EXERT.