Who will stay and who will go? A review of older adults' adherence to randomized controlled trials of exercise

This study examined exercise-adherence rates and their predictors across 21 randomized controlled trials (RCTs) involving older adults (age greater th an or equal to 55 years). On average, participants completed 78% of their p rescribed exercise bouts. Adherence tended to be greater in strength- and f lexibility-exercise training programs (M = 87%) than in aerobic-exercise tr aining programs (M = 75%). The best adherers were individuals who were fitt er at baseline, had a history of a physically active lifestyle, were nonsmo kers, and had higher exercise self-efficacy. Different variables predicted adherence (a) at different time points in a RCT, (b) to different types of exercise, and (c) to different aspects of the exercise prescription (i.e., frequency, intensity, and duration). The findings suggest that older adults might be more adherent to exercise prescriptions than younger adults are. There is also a need for more theory-based research to examine predictors o f adherence to various aspects of the exercise prescription.