What is the relationship between physical activity and risk of prostate cancer?

Overall, epidemiological research does not indicate that there is an inverse relationship between physical activity and prostate cancer. Although it is possible that men who are the physical experience of a reduction in the risk of prostate cancer, the possible biological mechanisms that might explain this association is unknown but may be related to changes in hormones, energy balance , factors like insulin growth, immunity, and the antioxidant defense mechanisms. A recent study suggests that regular vigorous activity could slow the progression of prostate cancer in men over 65 years.

Source; National Cancer Institute