A new study reported in JAMA Oncology suggests increasing the recommended 150 minutes of exercise to 300 minutes/week can reduce fat levels enough to lower the risk of developing breast cancer.
Friedenreich CM, Neilson HK, O'Reilly R, et al. Effects of a High vs Moderate Volume of Aerobic Exercise on Adiposity Outcomes in Postmenopausal Women: A Randomized Clinical Trial. JAMA Oncol. Published online July 16, 2015. doi:10.1001/jamaoncol.2015.2239.