According to the National Cancer Institute, one in eight women in the United States will develop breast cancer during her lifetime, and nearly 80 percent will be diagnosed after age 50.   While most women diagnosed with the disease have no family history or known risk factors, previous research suggests that physical activity reduces the risk. However, the precise amounts, timing (i.e., when initiated in life) and type of exercise remain unknown - until now.   A study published in the Journal of the American Medical Association found that postmenopausal women who had "engaged in regular, strenuous exercise" after age 35 had a 14 percent reduced risk of developing breast cancer compared with less active women in their same age group. This is significant because many women take hormone therapy following menopause, which has been shown to increase the risk for breast cancer.   So get off the couch and start exercising! Besides helping prevent breast cancer, a consistent exercise regimen can help maintain ideal weight and reduce the risk of developing hypertension, diabetes, and cardiovascular disease. If you need help starting (or maintaining) an exercise program, or would like a professional evaluation of what type of exercise may work best for you, schedule an appointment with your doctor of chiropractic.   For more on the benefits of exercise, plan to attend one of our workshops geared towards exercise and you or book a complimentary consultation to discuss your needs.   Reference: McTiernan A, Kooperberg C, White E, et al. Recreational physical activity and the risk of breast cancer in postmenopausal women. Journal of the American Medical Association, Sept. 10, 2003:290(10), pp1331-36.