The Relationship between Exercise Self-Efficacy, Intention, and Structural Barriers for Physical Activity after a Cancer Diagnosis

SIMPLE SUMMARY: Despite numerous benefits of physical activity for cancer patients, the majority is insufficiently active. Previous research has shown that structural barriers negatively affect patients’ physical activity behavior. Identifying underlying mechanisms could help to develop effective strategies that alleviate those barriers and increase physical activity levels. In the current survey study, we investigated whether cancer patients’ self-efficacy, i.e., their confidence in their ability, and their intention to exercise mediated the relationship between structural barriers and physical activity. The results revealed a negative relation between structural barriers and patients’ self-efficacy. Lower self-efficacy, in turn, decreased patients’ intention and their likelihood to engage in physical activity. This mediating effect especially applied to those individuals who were sufficiently active before the diagnosis. Thus, the findings suggest that interventions directly addressing the perception of structural barriers or patients’ self-efficacy in dealing with these barriers might be effective in improving the physical activity levels of cancer patients. ABSTRACT: Previous research has shown that structural barriers negatively influence the physical activity (PA) behavior of cancer patients, but underlying mechanisms are unclear. The aim of the current study was to explore the potential mediating role of social-cognitive factors, namely PA self-efficacy and PA intention in this context. A total of 856 cancer patients completed a questionnaire on sociodemographic and medical characteristics, pre- and post-diagnosis PA, PA self-efficacy, PA intention, and PA impediment by structural barriers. A serial mediation model was used to test whether the association between structural barriers and post-diagnosis PA was mediated by PA self-efficacy and/or PA intention, in the overall sample and in subsamples defined by individuals’ pre-diagnosis PA. The results confirmed that structural barriers were not directly (95%CI [−0.45; 0.10]) but indirectly associated with post-diagnosis PA. Higher impediment by structural barriers decreased the likelihood of sufficient post-diagnosis PA via lower PA self-efficacy (95%CI [−0.25; −0.06]) and via the serial pathway of lower PA self-efficacy and lower PA intention (95%CI [−0.19; −0.05]). Investigating differences in these mediations by pre-diagnosis PA yielded significance only among previously active cancer patients. Both structural barriers and PA self-efficacy might hence be relevant target points for interventions aiming to improve PA behavior, especially among pre-diagnosis active cancer patients.