Exercise Intervention for Reducing Fatigue in Patients with Locally Advanced, Unresectable or Metastatic Breast Cancer being Treated with Enhertu, ENERGIZE Trial

Inclusion Criteria

• Subject aged >= 18 years
• Diagnosis of locally advanced/unresectable or metastatic breast cancer * Note: Patients with high-risk HER-2 + breast cancer after completion of neoadjuvant chemotherapy requiring adjuvant Enhertu are allowed at the discretion of the treating physician
• Has received 3 or 4 cycles of Enhertu and is expected to continue treatment for at least 12 weeks * Note: HER-2 targeted systemic therapy (e.g. trastuzumab and/or pertuzumab) in conjunction with Enhertu is allowed
• Able and willing to participate in the interventional aerobic exercise and resistance exercises
• Currently following standard of care contraception requirements and willing to continue following these requirements for the duration of therapy
• Able to provide informed consent and willing to sign an approved consent form that conforms to federal and institutional guidelines
• Experiencing clinical fatigue symptoms in the opinion of the investigator
• Subject has completed the American College of Sports Medicine (ACSM) exercise preparticipation health screening and is, in the opinion of the investigator, fit to participate in this study

Exclusion Criteria

• Currently adhering to national physical activity guidelines for resistance training, as defined as participating in structured resistance training >= two days per week. * Structured is defined as time set aside in the subject's day to workout. * Resistance training is defined as exercises which use weights, bands, or body weight (e.g., squats or push-ups). AND Currently participating in structured moderate-intensity aerobic exercise for >= 150 minutes per week. * Moderate-intensity exercise is defined as activities where the subject can talk but not sing. * Aerobic exercise includes, but is not limited to, walking, swimming, cycling, running, rowing, hiking, and elliptical
• Medical, psychiatric, cognitive, or other conditions that may compromise the participant's ability to understand the participant information, give informed consent, comply with the study protocol or complete the study
• Participants taking prohibited medications