Raloxifene With or Without Exercise Compared With Exercise Alone in Women Who Have Been Previously Treated for Breast Cancer

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