Something Strange Happens to Brains During a Marathon

It’s not just our legs that get put through the wringer during a marathon, new research suggests. Scientists have found evidence that our brains can undergo dramatic changes while we’re running an extreme long distance race. Researchers in Spain conducted the study, published Monday in the journal Nature Metabolism. They scanned the brains of people before and after running a marathon, finding that runners experienced a significant, but temporary reduction of myelin in certain regions. The results indicate that our brains can use the fat stored in myelin as an emergency source of energy when pushed to the limit, the researchers say. Marathons are grueling tests of endurance, requiring participants to run 26.2 miles. While running a marathon or any kind of prolonged exercise, we initially rely on stored carbohydrates (glucose) for fuel. But eventually, this fuel runs low, prompting our bodies to burn off stored fat instead. Research in rodents has suggested that brains can use myelin ... Read full article.