Intrinsic motivation and exercise adherence

Two prospective studies tested the hypothesis that intrinsic motives for physical activities facilitate long-term adherence. In Study 1, participants in two physical activity classes, Tae Kwon Do and Aerobics (N = 40), were compared in their motives for participating using the Motivation for Physical Activity Measure (MPAM; Frederick & Ryan, 1993). Participation motives were also used to predict adherence. Results showed that Tae Kwon Do participants were higher in enjoyment and competence motives and lower in body-related motives than those in aerobics. They also showed better adherence. Further analyses revealed that group differences in adherence were mediated by enjoyment motives. Body-focused motives were unrelated to adherence. In Study 2, subjects joining a nautilus center (N-155) rated their initial motives on a revised Motivation for Physical Activity Measure (MPAM-R). They also rated workout length, challenge, and enjoyment after each exercise session. Results revealed that adherence was associated with motives focused on enjoyment, competence, and social interaction, but not with motives focused on fitness or appearance. Post-workout ratings of enjoyment also predicted adherence. Discussion focuses on the importance of intrinsic motivation for exercise adherence.