Rationale: Exercise therapy may improve the quality of life of breast cancer survivors.

Purpose: This randomized clinical trial studies exercise therapy and quality of life in postmenopausal early breast cancer survivors receiving aromatase inhibitor therapy.

PRIMARY OBJECTIVES:

I. To determine whether a 16-week exercise intervention will improve components of metastasis (MetS) in breast cancer survivors soon after completion of cancer-related treatments by measuring changes in body composition, waist circumference, blood pressure, and serum levels of insulin, glucose, lipids, C-reactive protein, and hemoglobin A1c (HbA1c).

II. To determine whether a 16-week exercise intervention will improve physical fitness in breast cancer survivors soon after completion of cancer-related treatments by measuring cardiorespiratory fitness and muscle strength.

III. To assesses the feasibility of a supervised exercise intervention in early breast cancer survivors.

IV. To determine whether a 16-week exercise intervention will result in a reduction in adipose tissue inflammation in obese breast cancer survivors soon after completion of cancer-related treatments by measuring ATM phenotype and ATM cytokine expression.

V. To determine whether breast cancer survivors can maintain positive benefits of an exercise intervention following a 12-week follow-up period by measuring changes in body composition, waist circumference, blood pressure, and serum levels of insulin, glucose, lipids, C-reactive protein, and HbA1c, cardiorespiratory fitness and muscle strength.

OUTLINE:

Patients are randomized to 1 of 2 arms.

Arm I (Control): Patients refrain from increasing physical activity levels for 16 weeks.

Arm II (Exercise): Patients participate in supervised exercise sessions over 60 minutes thrice weekly and are encouraged to participate in a home-based exercise session over 30-45 minutes once weekly for 16 weeks.

Inclusion Criteria:

• Newly diagnosed (I-III) with a first primary invasive breast cancer
• Have undergone a lumpectomy or mastectomy
• Have completed neoadjuvant/adjuvant chemotherapy and able to initiate Exercise program (if randomized to that arm) within 12 weeks of therapy completion
• Body mass index (BMI) > 25 kg/m^2 or body fat > 30% (determined by Dr. Dieli-Conwright at baseline visit)
• Currently participate in less than 60 minutes of physical activity per week May use adjuvant endocrine therapy if use will be continued for duration of study period
• Nonsmokers (i.e., not smoking during previous 12 months)
• Willing to travel to the exercise facility and USC
• Able to provide physician clearance to participate in exercise program
• Women of all racial and ethnic backgrounds will be included in the study enrollment process

Exclusion Criteria:

• History of chronic disease including diabetes, uncontrolled hypertension or thyroid disease
• Weight reduction >= 10% within past 6 months
• Diagnosed with human epidermal growth factor receptor 2 (HER2)-positive tumor (exclusion due to patient use of Herceptin medication for 1 year following chemotherapy)
• Metastatic disease
• Planned reconstructive surgery with flap repair during trial and follow-up period
• Cardiovascular, respiratory or musculoskeletal disease or joint problems that preclude moderate physical activity