Generally speaking, how can physical activity lower your risk of cancer? Specifically, what is the ...

Physical activity may reduce the risk of several cancers. In addition to helping maintain a healthy body weight, exercise may help prevent cancer by regulating sex hormones, insulin, and prostaglandins and by enhancing the immune system.According to the American Institute for Cancer Research, physical activity may lower the risk of colon cancer by 40 to 50 percent; the risk of breast, endometrial, and lung cancers by 30 to 40 percent; and the risk of prostate cancer by 10 to 30 percent. Along with a healthful diet and limited alcohol intake, regular exercise could prevent about 340,000 cancer cases a year.

The combination of excess weight and physical inactivity may account for one-quarter to one-third of all breast cancer cases. Regular, lifelong exercise may lower a woman's breast cancer risk by 20 percent, possibly by reducing weight and body mass and preventing metabolic syndrome and chronic inflammation. Men who regularly get moderate exercise may have a lower risk of developing prostate cancer; those who do get the disease are less likely to have aggressive, fast-growing tumors.

Very good answer