Abstract
Posttraumatic growth (PTG) is the experience of positive psychological growth following adversity, such as a breast cancer diagnosis. There is preliminary theoretical evidence to suggest that physical activity may promote PTG in breast cancer survivors (BCS); however, causal mechanisms are not well defined. Social support is a theoretical predictor of PTG and may mediate the physical activity-PTG relationship, as physical activity contexts can create opportunities for social support. The aims of this study were to (i) test physical activity as a predictor of PTG and (ii) examine the mediating role of social support on this relationship. BCS (N=153, Mage=55, SD=11) completed self-reported measures assessing physical activity, social support and PTG at one-year post-primary treatment completion. Mediation models, controlling for ethnic background, body mass index, and marital status were estimated. There was a direct effect of physical activity on PTG (beta= .01, BCa CI=.002, .018) and an indirect effect through social support (beta= .001, BCa CI=.001, .004). Physical activity accounted for 9% of the variance in social support. Both physical activity and social support accounted for 15% of the variance in PTG. These findings demonstrate that obtaining social support and engaging in physical activity are associated with PTG in BCS, and that social support may be a mechanism by which physical activity fosters PTG. Further research is warranted to determine temporal causality through longitudinal and experimental designs. Improved understanding of the relationship between social support, physical activity and PTG will inform interventions to help BCS better cope with cancer.
