Inclusion Criteria:  active diagnosis of primary invasive non-metastatic breast cancer, hormone receptor positive (HR+)/ human epidermal growth factor receptor 2 negative (HER2-) subtype, stages I-III female 50 years of age or older postmenopausal at time of breast cancer diagnosis as determined by their medical oncologist scheduled to initiate neoadjuvant or adjuvant chemotherapy (anthracycline, alkylating agent and/or taxane) absence of contraindications to exercise medical oncologist approval able to give consent informed consent obtained from the subject and documentation of subject agreement to comply with study-related process  Exclusion Criteria:  do not meet inclusion criteria receiving targeted therapies (HER2, CDK4/6 or PPAR inhibitors) receiving radiation therapy concurrent with chemotherapy any relevant cardiovascular diseases (stroke, heart failure, myocardial ischemia during maximal graded exercise test, myocardial infarction, angina pectoris, coronary artery bypass surgery or angioplasty or coronary stent) body mass index ≥ 40 kg/m2 current participation in other experimental interventions that may confound interpretation of study findings (e.g., dietary intervention for weight loss) current participation in aerobic exercise training