Breast cancer stands as the foremost cause of cancer-related deaths among women worldwide, with the highest incidence of any cancer type. The choice of therapeutic interventions hinges upon factors like cancer stage, cell subtype, and tumor size. Consequently, individuals with more aggressive tumors, such as HER+2 and Triple Negative, or larger tumors often undergo neoadjuvant chemotherapy before breast surgery. However, these anticancer treatments come with side effects like cancer-related fatigue, reduced functional capacity, and changes in body composition, notably skeletal muscle atrophy. Skeletal muscle loss correlates with heightened mortality rates, cardiotoxicity, and diminished quality of life, underscoring the need for early therapeutic interventions. One such promising strategy is prehabilitation, which involves resistance-exercise training aimed at bolstering skeletal muscle mass from the outset of the disease, even preceding breast surgery. Resistance-exercise training has shown favorable effects on women undergoing adjuvant therapy or survivors of breast cancer, however, its molecular and clinical effects in women with breast cancer undergoing neoadjuvant therapy are unknown.