An application of the theory of planned behavior to exercise among older adults

One hundred five older adults enrolled in exercise classes were recruited from local YMCAs. Exercise behavior was measured 1, 3, and 9 months after beginning the exercise class. Intentions were not a significant predictor of exercise behavior, probably because of a lack of variance; most people intended to exercise. The direct measures of attitudes, subjective norms, and perceived behavioral control, however, explained 9% of exercise behavior at 1 month. They did not significantly explain behavior at 3 and 9 months. When the indirect measure of subjective norms explained 18% of exercise behavior at 1 month. The indirect measure of perceived behavioral control accounted for 27% of the variance at 1 month and 10% at 3 months.