Postmenopausal breast cancer risk: Intensity and timing of exercise

Intensity and timing of physical activity in relation to postmenopausal breast cancer risk: the prospective NIH-AARP Diet and Health Study

"A high level of recent, but not historical, physical activity of moderate-to-vigorous intensity is associated with reduced postmenopausal breast cancer risk."

BMC Cancer. 2009 Oct 1;9(1):349.