Physical Activity Reduces Breast Cancer Risk at Any Age Says Study of Four Million Women

March 20, 2014 – A new study leaves little doubt that physical exercise – at least one hour per day – reduces the risk of breast cancer for women of any age or size, regardless of where they live. The researchers reviewed all the studies – 37 – published from 1987 to 2013 that included four million women. Those with the highest level of physical activity reduced the risk by 12 percent.