Physical activity intensity and breast cancer risk
It’s fairly well accepted that regular physical activity appears to lower breast cancer risk. Recent findings suggest that there is also an association between the difficulty of the exercise and the risk — tougher, or longer-lasting moderate, exercise, appears to reduce the risk better.
Once again, research concludes: butch up.
Kruk, Joanna. 2009. Intensity of lifetime physical activity and breast cancer risk among Polish women. Journal of Sports Sciences. 27(5):437-445.
Partial abstract: Research findings are inconsistent regarding the type, duration, intensity, and frequency of activities that are necessary to reduce the risk, as well as dependence on menopausal status. To address these issues, I examined the effect of physical activity on breast cancer risk among 858 Polish invasive breast cancer cases and 1085 controls… [F]indings show that a risk reduction can be achieved by vigorous-intensity activities or by longer-lasting activities of moderate-intensity.