Goals of work Although exercise can provide a range of benefits for women living with a breast cancer diagnosis, many impediments to exercise exist. Several psychosocial and physical capacity impediments to exercise have been investigated, but no study has systematically investigated whether bras impede breast cancer patients from exercising. This study aimed to assess the extent to which exerciseinduced breast pain and bra discomfort were reported by women living with breast cancer and whether this breast pain and bra discomfort impeded these women from participating in physical activity. Patients and methods Seventy-four women living with a breast cancer diagnosis completed a custom-designed questionnaire. Frequency data were analyzed to identify the most common barriers to exercise, and features in current bra designs causing discomfort during exercise were established. Main results When analyzed according to mean score, “bra discomfort” ranked as the fourth highest barrier to exercise behind a lack of self-discipline, procrastination, and fatigued by exercise. A significant 70.3% of the sample (p<0.001) reported experiencing bra discomfort during exercise. Over half (57.7%) of these respondents reported the band as the most uncomfortable part of the bra. Conclusions This study has clearly established that bra discomfort, particularly bra band tightness, is a barrier to participating in physical activity for women living with a breast cancer diagnosis. To further encourage exercise in women living with a diagnosis of breast cancer, potential barriers to exercise, such as inadequate bra design, need to be modified to enable these women to enjoy the health benefits of exercising in comfort.