DISEASE CHARACTERISTICS:

• Histologically confirmed breast cancer
• No metastatic disease
• At least 3 months but no more than 1 year since prior chemotherapy regimen including doxorubicin or methotrexate and catabolic steroids (to prevent nausea, vomiting, fluid retention, or hypersensitivity reactions)
• No routine of regular strenuous exercise (more than 90 minutes per day 6 days/week OR 120 minutes per day 4 days/week)

• Hormone receptor status:

  • Estrogen and progesterone receptor negative OR
  • Estrogen and progesterone receptor positive

PATIENT CHARACTERISTICS:

Age:

• Any age

Sex:

• Female

Menopausal status:

• Postmenopausal (at diagnosis OR chemotherapy-induced)
• No spontaneous menses for more than 6 months with increased follicle-stimulating hormone and decreased estradiol

Performance status:

• Ambulatory

Life expectancy:

• Not specified

Hematopoietic:

• Not specified

Hepatic:

• Not specified

Renal:

• Not specified

Cardiovascular:

• No cardiac problems that would preclude exercise
• No unstable angina

Pulmonary:

• No respiratory problems that would preclude exercise
• No chronic obstructive pulmonary disease
• No oxygen dependence

Other:

• No endocrine disease (e.g., parathyroid hormone disorders) that would accelerate bone turnover and loss
• No musculoskeletal problems or other disease that would preclude exercise (e.g., movement-limiting arthritis, muscular dystrophy, or chronic fatigue syndrome)
• No known cognitive or psychiatric disorders that would preclude study

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• See Disease Characteristics
• Prior adjuvant or neoadjuvant chemotherapy allowed
• No concurrent chemotherapy

Endocrine therapy:

• See Disease Characteristics
• No concurrent tamoxifen

Radiotherapy:

• Prior adjuvant radiotherapy after chemotherapy allowed
• No concurrent radiotherapy

Surgery:

• Not specified

Other:

• No concurrent bisphosphonates