Lots of Exercise Lowers Breast Cancer Risk
The study, published in the journal BMC Cancer, found women who reported exercising more-than-moderately for seven or more hours a week were 16 percent less likely to develop breast cancer than those who did not exercise.
However, the study which also surveyed activity at various age levels in the more than 110,000 post-menopausal women, found no link between breast cancer risk and being active at a younger age.
The women were asked to rate their level of physical activity at ages 15-18, 19-29, 35-39, and in the past 10 years.
"Our findings could help inform the mechanisms of the physical activity-breast cancer relationship," study leader Dr. Tricia Peters of the U.S. National Cancer Institute in Bethesda said in a statement.
"With breast cancer still claiming so many lives, all the information of potential preventive measures we can get is vital."