Abstract
PURPOSE: Physical activity (PA) has been consistently associated with improved self-esteem in breast cancer survivors. However, this relationship is poorly understood. The purpose of this study was to examine whether changes in PA and self-efficacy influenced changes in self-esteem in breast cancer survivors across 6 months. Increases in PA were hypothesized to result in increases in self-efficacy, which were hypothesized to influence increases in physical self-worth (PSW) and global self-esteem. METHODS: Breast cancer survivors (n = 370; M(age) = 56.04) wore accelerometers to measure PA and completed measures of self-efficacy (e.g., exercise and barriers self-efficacy), PSW, and global self-esteem at baseline and 6 months. RESULTS: The hypothesized model provided a good fit to the data (χ(2) = 67.56, df = 26, p < 0.001; comparative fit index (CFI) = 0.98; standardized root mean residual = 0.05). Women with higher activity at baseline reported significantly higher levels of barrier (β = 0.29) and exercise (β = 0.23) self-efficacy. In turn, more efficacious women reported significantly higher PSW (β = 0.26, 0.16). Finally, higher PSW was significantly associated with greater global self-esteem (β = 0.47). Relationships were similar among changes in model constructs over 6 months. After controlling for covariates, the hypothesized model provided an excellent fit to the data (χ(2) = 59.93, df = 33, p = 0.003; comparative fit index = 0.99; standardized root mean residual = 0.03). CONCLUSION: Our findings provide support for the role played by PA and self-efficacy in positive self-esteem, a key component of well-being. Highlighting successful PA mastery experiences is likely to enhance self-efficacy and improve self-esteem in this population. Copyright © 2016 John Wiley & Sons, Ltd.