--Disease Characteristics-- Stage 2 or 3 Parkinson disease (Hoehn/Yahr scale) Able to ambulate independently Able to function independently in home Moderate rigidity No moderate or severe tremor --Prior/Concurrent Therapy-- Concurrent stable pharmacologic regimen required --Patient Characteristics-- Cardiovascular: No unstable angina Other: No psychiatric or medical contraindication to exercise, e.g., dementia, hip fracture; no other neurologic disorder, e.g., stroke, multiple sclerosis; resides within 30 miles of Duke University