Abstract
Background: Exercise is associated with an improved quality of life among cancer survivors. Previous research has highlighted the utility of the theory of planned behavior in understanding cancer survivors' intention to exercise. The purpose of this study was to extend the research on the theory of planned behavior in relation to exercise intention in breast cancer survivors and to provide preliminary evidence supporting its application with prostate cancer survivors during treatment. Methods: Participants consisted of 126 breast and 82 prostate cancer survivors receiving active treatment. Participants completed self-administered, mail-in questionnaires that assessed demographic and medical variables, past exercise, and the theory of planned behavior. Results: For breast cancer survivors, the results revealed that attitudes, subjective norm, and perceived behavioral control explained 66% of the variance in exercise intention with the instrumental component of attitude, subjective norm, and perceived behavioral control making significant unique contributions to intention. For prostate cancer survivors, attitudes, subjective norm, and perceived behavioral control explained 57% of the variance in exercise intention, with subjective norm and perceived behavioral control making significant unique contributions to intention. Conclusions: The results provide further support that the theory of planned behavior is a useful framework for understanding determinants of exercise intention in breast cancer survivors undergoing active treatment and preliminary support for prostate cancer survivors undergoing active treatment. When designing exercise interventions, differences in breast and prostate cancer survivors' exercise intention merit consideration.