There’s a well-established link between physical activity and breast cancer prevention. Women who get regular physical activity, especially if that activity is of moderate to vigorous intensity, have a 10 to 30 percent lower risk of breast cancer than do inactive women. This is especially true among postmenopausal women, indicating that’s never too late to start reaping the benefits of exercise. Two studies from Yale University found that exercise and weight loss reduced levels of a certain protein associated with a higher risk of breast cancer death. And, as little as two to three hours a week of moderate exercise such as brisk walking has been found to reduce breast cancer recurrence by 40 to 67 percent.

Source:  Special Report Supplement to Mayo Clinic Health Letter  August 2016