The Influence of Affective and Instrumental Beliefs on Exercise Intentions and Behavior: A Longitudinal Analysis

Programs encouraging exercise might reduce coronary illness. Ajzen's theory of planned behavior is a useful model for understanding exercise motivation. The current study investigated the contribution of the instrumental and affective components of attitude. As part of a community-based study of exercise behavior, 424 men and 572 women completed questionnaires, with 365 participants providing 6-month follow-up data. Regressions highlighted the affective component as a much more powerful predictor of intention compared to the instrumental component. After controlling for prior exercise, intention was not predictive of later exercise, although the affective component was. The implications for exercise promotion are discussed.