Supervised Exercise During Neoadjuvant Chemotherapy for Breast Cancer

The goal of this clinical trial is to learn whether supervised exercise is practical and safe for women receiving chemotherapy before surgery for breast cancer. The main questions it aims to answer are: * Can participants attend and complete the supervised exercise program during chemotherapy? * Is the exercise program safe? * Does exercise help maintain muscle mass, strength, quality of life, and chemotherapy delivery? Participants will be assigned to either: * supervised aerobic and strength exercise during chemotherapy, or * usual care without a study exercise program. Researchers will compare the two groups before and after chemotherapy.