Aim: Exercise is an effective strategy for women with breast cancer to manage physical and psychological treatment-related side effects. However, exercise levels typically decline during treatment. This study describes exercise behaviour in the 18 months following breast cancer surgery and examines predictors of behaviour.
Methods: Women (n=203) aged 58.4±10.5 years enrolled prior to surgery for breast cancer. Eighty percent received radiotherapy and 47% chemotherapy. Women completed weekly diaries reporting exercise and were physically assessed for lymphoedema at 6, 12 and 18 months. Based on diaries, participants were categorised as completing aerobic or resistance exercise, or not, during the 6 months preceding each assessment. Relationships between exercise and clinical, medical, demographic, anthropometric and baseline activity variables were assessed using chi-square and significant variables (p<0.2) examined with a multivariate model.
Results: Prior to surgery, 95% reported aerobic exercise, dropping to 13%, 23% and 38% at 6, 12 and 18 months, respectively. Post-surgery resistance training levels were minimal at 6 (0%), 12 (1%) and 18 months (1.5%). In adjusted analysis, factors associated with aerobic exercise at 18 months were baseline activity ≥50min/wk of moderate-vigorous physical activity (MVPA; vs. <50min/wk; AOR: 2.3, p=0.03) and ≥105 mins/wk of walking (vs. <105min/wk; AOR: 3.1, p<0.01), and working (vs. not working; AOR: 2.7, p<0.01). It was not possible to explore relationships with resistance training due to small numbers.
Conclusion: Aerobic and resistance exercise levels among breast cancer patients following surgery are low. Women who worked and had higher levels of MVPA and walking prior to surgery were more likely to engage in aerobic activity at 18 months, with clinical and medical variables playing a limited role. Given the benefits of exercise, support from medical and exercise professionals is essential to encourage exercise during breast cancer treatment, particularly for those who were previously inactive.