Marathon running may seem like the ultimate sport for staying in shape. That said, it can take a heavy toll on the body, potentially damaging the kidneys, upsetting the stomach, increasing the risk of heart failure, and triggering musculoskeletal injuries. Let's not forget that the original marathon runner, the ancient Greek soldier Pheidippides, is said to have dropped dead immediately after reaching his destination.
Now, a new study suggests that marathons also affect the brain — causing the organ to eat itself to make up for fuel lost during the run.
