9115 Background: There is minimal research examining the effect of cardiovascular and resistance exercise after surgery and/or radiation treatment to the breast and axillary area. Currently there are no guidelines for activity restrictions; however, medical providers historically have recommended limiting activity of the affected arm in an attempt to prevent the development of lymphedema. This could potentially affect future quality of life and other medical issues in breast cancer survivors. Methods: Female breast cancer survivors (n=79) completed an 8-week group exercise program meeting two days per week for cardiovascular and resistance training. Participants were also encouraged to exercise independently in addition to their group sessions. Bilateral arm girth measurements were performed on all participants upon program entry and exit. Measurements were taken distal to the ulnar styloid process (wrist) and three inches above (upper arm) and below (elbow) the lateral epicondyle of the elbow. All participants included in this analysis attended ≥ 70% of the group exercise sessions and had complete entry and exit measurements. Results: Participants attended an average of 15.94 ± 3.75 exercise sessions during the 8 week program. Changes in arm girth measurement were compared for the surgical side and non-surgical sides of the body using paired t-tests. Arm girth changes in the surgical side of the body were compared to the non-surgical side of the body using the Wilcoxon Ranked Sum test. The surgical and the non-surgical arm girths did not significantly increase at the wrist (p=0.55 and p=0.76), elbow (p=0.31 and p=0.24) or upper arm (p=0.18 and p=0.42). The changes in arm girth observed on the surgical body side were not significantly different from the changes observed on the non-surgical side (wrist (p=0.67), elbow (p=0.44), and upper arm (p=0.36). Conclusions: A structured, group-based exercise program involving both cardiovascular and resistance training did not significantly increase arm girth measurements in breast cancer survivors.