Research has demonstrated that virtually all individuals will benefit from regular physical activity. Moderate physical activity can reduce substantially the risk of developing or dying from heart disease, diabetes, colon cancer, and high blood pressure. Physical activity also may protect against lower back pain and some forms of cancer. On average, physically active people outlive those who are inactive. People with osteoporosis may respond positively to regular walking.

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http://www.holistichealthco-op.org/
http://www.healthypeople.gov/Document/word/Volume2/22Physical.doc