Adherence to a randomized controlled trial of aerobic exercise in breast cancer survivors: the Yale exercise and survivorship study

Purpose To examine predictors of exercise adherence in breast cancer survivors. Methods Seventy-five breast cancer survivors were randomly assigned to exercise (n=37) or usual care (n=38). Demographic, prognostic, physiologic, and psychosocial information was collected at baseline and 6 months. The exercise goal was 30 min of exercise 5 days/week for 6 months. Results Women randomized to exercise participated in moderate-intensity recreational exercise for 123 +/- 52 min/week (81% of the prescribed 150 min/week) over 6 months. Baseline variables associated with better adherence were lower body mass index (BMI), smaller waist circumference, higher amounts of physical activity 6 months prior to enrollment, being in the preparation vs. contemplation Stage of Change and higher FACT-B breast cancer subscale score. After adjusting for these variables, lower BMI and higher Stage of Change continued to be associated with better adherence (p<0.05). Conclusions Future studies of exercise and breast cancer prognosis should target obese women for participation, as well as women just beginning to contemplate participation and its benefits after a cancer diagnosis.