Ormel HL, Schröder CP, van der Schoot GGF, et al. - This multicentre single-arm clinical trial was conducted to determine if supervised exercise elevated the proportion of patients adhering to the national physical activity (PA) guideline during adjuvant endocrine therapy (ET) in overweight or obese breast cancer (BC) patients. This study involved patients suffering from BC engaging in a 12-week supervised exercise intervention. At baseline, following 12 and 26 weeks, moderate to vigorous PA was recorded using an accelerometer. Over time, an increase in the proportion of BC patients adhering to the PA guideline was shown to be conferred by supervised exercise. In addition, improvements were seen in metabolic syndrome, body composition, health-related quality of life and symptoms. These data underscore the clinical importance of supervised exercise during ET in overweight BC cases.