October is Breast Cancer Awareness Month. A new study shows that more exercise and less sitting might decrease your risk of breast cancer. In the study, published in the British Journal of Sports Medicine, researchers used genetic markers from hundreds of thousands of European women and linked them to physical activity, sedentary time, and cases of breast cancer. The researchers found strong evidence that greater overall physical activity, greater vigorous activity, and lower sedentary time, like sitting less at work and at home, are likely to reduce breast cancer risk, for all types and stages of breast cancer.