28th Annual Congress of the EUROPEAN COLLEGE OF SPORT SCIENCE 4 – 7 July 2023 BOOK OF ABSTRACTS Edited by: Guilhem, G., Rabita, G., Brocherie, F., Tsolakidis, E., Ferrauti, A., Helge, J.W., Piacentini, M.F.

INTRODUCTION: Breast cancer survivor (BCS) women are at increased risk for developing diabetes and metabolic syndrome compared to cancer-free women [1]. Aerobic exercise is an effective strategy for improving glycemic control; however, the association between exercise and glucose homeostasis in BCS has remained inconclusive [2]. The main aim of this study is to evaluate the effects of a supervised aerobic exercise training program on glycemic control in BCS. METHODS: Sixteen non-diabetic BCS were randomly assigned to an intervention arm (IA; n = 8) or control arm (CA; n = 8). Both groups received lifestyle recommendations, in addition, the IA received a 12-week aerobic exercise training program with a progressive increase in exercise intensity (40%-70% of HRR) and duration (20-60 min). Anthropometric measurements (BMI, weight, waist circumference, % body fat) and metabolic markers (glucose, insulin, triglycerides, LDL, and HDL) were analyzed at baseline and after the 12-week intervention period. Moreover, food intake and indices of glycemic variability obtained by continuous glucose monitoring (CGM) were analyzed in the first and last 14 days of the study intervention.RESULTS: At the end of the study, the VO2 max increased by 2.2% in the CA group (p=0.64) and by 16.4 % in the IA group measurements and other metabolic markers did not improve after the intervention period. The caloric intake was in- increased at the end of the study both in CA (19%, p=0.06) and IA (28.1%, p=0.03). The analysis of 24h CGM data reveals that time spent in a hyperglycemic state (glucose >140 mg/dL) slightly increased in the CA group after the intervention period, while it remained stable throughout the study in the IA group. The baseline patients' BMI and the improvement of VO2 max were strong predictors for the reduction of intraday glucose variability indices. CONCLUSION: Anthropometric and metabolic parameters were only slightly modified after the 12-week aerobic exercise program in BCS, despite a significant improvement in cardiorespiratory fitness. The increased caloric intake observed at the end of the study might at least partially explain these findings. Interestingly, the CGM data showed that BCS with high BMI and those who strongly improved their VO2 max ameliorated the time spent in hyperglycemic ranges and glucose variability indices. [1] Ariaans G. Cancer Treat Rev. 2015;41:376 [2] Campbell KL. J Acad Nutr Diet. 2012; 112:559 Acknowledgments: we thank Innovation Zed Ltd. for providing GCM devices.