This study will test any good and bad effects of aerobic exercise performed while you are receiving the usual first-line treatment for metastatic breast cancer. The researchers think that exercise helps delay the development of resistance to hormone therapy while slowing the growth of tumors.
Patients with histologically-confirmed, HR-positive (ER and/or PR), HER2-negative metastatic breast cancer (MBC) Postmenopausal status defined by lack of menses for 2 years, oophorectomy, or medical ovarian suppression Receiving first line endocrine-based therapy (tamoxifen, aromatase inhibitor, or fulvestrant; concurrent molecular therapy also allowed) Sedentary (i.e., <60 minutes / week of exercise) Age >18 years BMI ≥ 18.5 Cleared for exercise participation as per screening clearance via PAR-Q+ Cleared for study participation as per screening consultation with an MSK Exercise Physiologist Willingness to comply with all study-related procedures Patients with "treated and stable" brain lesions of a duration of ≥ 2 months may be enrolled
Exclusion Criteria:
Life expectancy <6 months Enrollment onto any other therapeutic investigational study Mental impairment leading to inability to cooperate Concurrent participation in weight loss or other exercise programs
