Two new studies on mice show that exercise can act as a form of protection against skin and bowel cancer.
One study found that mice who used running wheels developed fewer and smaller skin tumors. The second study found that exercise reduced the number and size of intestinal polyps. One theory is that apoptosis (programmed cell death) is triggered by exercise, causing the cancer cells to die.
The studies also found that the number of tumors decreased along with body fat, which may be an additional factor.