Social cognitive determinants of hospital-based exercise in cancer patients following high-dose chemotherapy and bone marrow transplantation

Preliminary evidence indicates that physical exercise may be an effective strategy for the rehabilitation of cancer patients following bone marrow transplantation (BMT), but the determinants of such exercise are not known. In this study, we used a prospective design to evaluate the theory of planned behavior (Ajzen, 1991) as a social cognitive framework for understanding exercise motivation and behavior in 37 BMT patients. On admittance to the hospital, participants completed a baseline questionnaire that assessed the theory of planned behavior and then monitored the frequency and duration of self-initiated cycle ergometer exercise during their hospitalization. Hierarchical regression analyses demonstrated that intention and perceived behavioral control explained 36% of the variance in exercise behavior when the analyses were restricted to nonthrombocytopenic patients (n = 28). Moreover, attitude and perceived behavioral control explained 68% of the variance in exercise intentions. We concluded that the theory of planned behavior provided an excellent understanding of exercise intentions in this population and context and that its ability to predict exercise behavior could be improved substantially by taking into account significant medical complications.