Aims: Designing effective programs that support breast cancer survivors to adopt and maintain regular exercise requires an understanding of characteristics that influence exercise behaviour. Psychological factors in particular are considered manipulable through behaviour change intervention. The purpose of this analysis was to inform future theory-based interventions by exploring associations between exercise behaviour and three behavioural constructs from distinct theories: self-efficacy, motivation, and habits.

Methods: Breast cancer survivors (n = 204) completed an online cross-sectional survey that collected demographic and disease characteristics, exercise levels (Godin Leisure Time Exercise Questionnaire [GLTEQ] and a purpose-built resistance training item), and self-efficacy (Multidimensional Self-Efficacy for Exercise Scale), motivation (Behavioural Regulation in Exercise Questionnaire V2), and habit scores (Self-Report Habit Index). Multivariate linear regression models were used to identify psychological correlates of Total Activity (QLTEQ Score) and Resistance Training (sessions/week).

Results: Participants had a mean age of 57(11) years and were within 5-years post-diagnosis (median, min–max = 2, 0–5). Most participants were diagnosed with early-stage disease (72%) and engaged in sufficient levels of exercise (GLTEQ Score ≥24; 94%), though only 44% completed two or more resistance training sessions/week. Identified motivation (ß[95%CI] = 7.58[3.91–11.24]; p = <0.01) and habits (ß[95%CI] = 4.43[1.48–7.38]; p = <0.01) were found to be significant correlates of Total Activity (as were body mass index and stage of disease), whilst identified motivation (ß[95%CI] = 0.62[0.32–0.91]; p = <0.01) and coping self-efficacy (ß[95%CI] = 0.02[<0.01–0.03]; p = <0.01) were significant correlates of Resistance Training, explaining up to 26% and 15% of variance in Total Activity and Resistance Training exercise behaviour, respectively.

Conclusions: Although preliminary, these results may support the application of integrated theory-based interventions for improving exercise behaviour among breast cancer survivors and provide insight into how intervention techniques from distinct theories may be best integrated. Future research should explore these findings longitudinally to examine correlates of exercise maintenance and in a less active sample.