This trial studies how well weight bearing exercise works in preventing frailty in stage I-IIIA breast cancer survivors. Weight bearing exercise, including muscle-strengthening, aerobic, flexibility, and balance exercises, can decrease fat and increase muscle, which may lead to reduced frailty.

PRIMARY OBJECTIVES:

I. Demonstrate reproducibility of forearm muscle activation and subcutaneous fat measures in a healthy convenience sample/population (N= 10).

II. Demonstrate that measures of muscle activation and signal attenuation by subcutaneous fat mass can be conducted in a systematic and reproducible fashion in breast cancer survivors prior to and following weight bearing exercise training.

III. In a cross sectional analysis, describe the level of lean muscle mass, muscle activation, strength, insulin resistance, inflammatory cytokines and growth factors, and inter-individual variability in breast cancer survivors prior to training.

IV. Describe the level of lean muscle mass, muscle activation, strength, insulin resistance, inflammatory cytokines (such as IL-6, CRP and others), and growth factors (such as myostatin, IGF-1, IGFBP-3 and others) in breast cancer survivors following weight bearing exercise training.

V. Evaluate the influence of genetic variability on response to prescribed training in breast cancer survivors.

OUTLINE:

Participants undergo a weight bearing exercise program in a group 2 days a week and at home 5 days a week for 8 weeks.

Inclusion Criteria:

• Post-menopausal (12 months without menstrual period: naturally, surgically, by hormone suppression).
• History of early stage breast cancer (stage I, II, IIIa).
• At least 6 months from chemotherapy.
• May be receiving hormonal therapy during the study.
• Currently disease-free, including a negative mammogram within 1 year.
• Body mass index (BMI) between 25 and 40kg/m^2.
• In general good health with no acute or chronic disease that could worsen with weight bearing exercise.
• Not currently on a prescribed diet nor reporting weight loss of > 10 pounds (lbs) in previous 3 months.
• Not currently participating in physical activity (PA) independently or a structured program (performing < 120 min of low-intensity, low-impact exercise per week; and no weightlifting or similar physical activity).
• Ability to participate in physical activity, not limited by severe disability (e.g., severe arthritic conditions); chronic back pain, or history or presence of diseases for which increased physical activity would not be advised.
• No severe chronic disease, other than breast cancer (e.g., human immunodeficiency virus/acquired immunodeficiency syndrome [HIV/AIDS], kidney failure, liver failure, chronic obstructive pulmonary disease, congestive heart failure, Alzheimer?s, unstable angina, uncontrolled asthma, uncontrolled diabetes, uncontrolled hypertension).
• No implanted cardiac pacemaker, cardiac defibrillator, or other implanted electronic medical equipment.
• No history of drug or alcohol abuse.
• Able to remain in a lying or sitting position for an extended period (> 30 minutes).
• No history or presence of a significant psychiatric disorder or any other condition that would interfere with participation in the trial.
• Medical clearance by treating physician.
• Willing to discontinue nonsteroidal antiinflammatory drug (NSAID) use, except Tylenol and baby aspirin (80mg), 1 week prior to blood draws.
• Willing to maintain body weight during the study.
• Can be reached by telephone.
• Willing to complete consent process and sign informed consent form.