As a population, middle-aged and older adults are not meeting national guidelines for exercise. The purpose of this study was to describe factors associated with exercise adherence in an 8-month program offered as part of a research study testing the effects of exercise on cognitive performance for persons with a family history of Alzheimer's disease (AD). After completion of the program, participants provided open-ended responses indicating their reasons for adhering to the exercise program, and they completed the Motives for Physical Activities Measure-Revised. Results indicated that adherence was tied to an interest in contributing to our understanding of AD, the opportunity to join an exercise program, perceived exercise benefits, and social support. In addition, participants reported high levels of extrinsic (fitness-related) and intrinsic (interest/enjoyment) motivation. Other possible motivating factors which emerged from day-to-day observations in the program were identified. Findings suggest directions for exercise professionals with respect to exercise adherence.