Due to the prevalence of treatment-related health concerns and increased risk of developing metabolic syndrome, recurrence and cardiovascular disease, breast cancer survivors may require diagnostic, therapeutic, supportive or palliative services for many years post-diagnosis. Encouraging breast cancer survivors to adopt a healthy lifestyle post-treatment may reduce the healthcare burden resulting from treatment-related sequelae and improve survival. In particular, higher levels of physical activity (PA) may positively influence some of these side-effects of treatment, enhance quality of life and reduce risk of recurrence and all-cause and breast cancer-related mortality. However, PA levels are generally low among breast cancer survivors and many women decrease their PA following diagnosis. Therefore, interventions are required to improve the post-diagnosis PA levels of breast cancer survivors.