Does physical activity reduce my risk of cancer?

Yes.  Physical activity is consistently shown in high quality studies from around the world to decrease cancer risk.  Colon and breast cancer risk in particular is decreased through regular physical activity.  This doesn't mean running marathons - as little as 30 minutes of moderate intensity activity (such as a brisk walk) decreases risk.  Physical activity is also part of a healthy weight management strategy and overweight and obesity increase cancer risk independent of physical activity. 

Physical activity reduces your risk of cancer. Men over 65 who exercise regularly have a 70 percent lower risk of developing prostate cancer than their sedentary counterparts. Physically active men and women enjoy a 60 percent decrease in the risk of colon cancer. Regular exercise reduces a woman's risk of breast cancer by 50 percent. Exercise stimulates the production of immune cells that hunt down and destroy cancer cells. Try to get in at least 30 minutes of moderately intense exercise most days of the week to help prevent cancer.