Barriers to supervised exercise training in a randomized controlled trial of breast cancer patients receiving chemotherapy

Background: Exercise adherence is a challenge for breast cancer patients receiving chemotherapy but few studies have identified the key barriers. Purpose: In this paper, we report the barriers to supervised exercise in breast cancer patients participating in a randomized controlled trial. Methods: Breast cancer patients initiating adjuvant chemotherapy (N=242) were randomly assigned to usual care (n=82) or supervised resistance (n=82) or aerobic (n=78) exercise. Participants randomized to the two exercise groups (n=160) were asked to provide a reason for each missed exercise session. Results: The two exercise groups attended 70.2% (5,495/7,829) of their supervised exercise sessions and provided a reason for missing 89.5% (2,090/2,334) of their unattended sessions. The 2,090 reasons represented 36 different barriers. Feeling sick (12%), fatigue (11%), loss of interest (9%), vacation (7%), and nausea/vomiting (5%) accounted for the most missed exercise sessions. Disease/treatment-related barriers (19 of the 36 barriers) accounted for 53% (1,102/2,090) of all missed exercise sessions. Demographic and medical variables did not predict the types of exercise barriers reported. Conclusions: Barriers to supervised exercise in breast cancer patients receiving chemotherapy are varied but over half can be directly attributed to the disease and its treatments. Behavioral support programs need to focus on strategies to maintain exercise in the face of difficult treatment side effects.