#Athletic

A small, cutting-edge study suggests the brain may temporarily convert its own myelin into fuel during extreme endurance events like marathons. This unexpected mechanism could help protect overall brain function when glucose supply drops during intense exercise.

Researchers in Spain followed 10 marathon runners, scanning their brains with MRI before and after the races. They found that 24 to 48 hours after finishing a grueling 42-kilometer run, myelin levels in key brain regions—those governing movement, coordination, sensation, and emotion—decreased noticeably. Importantly, these changes were not permanent. By two weeks post-race, myelin began to recover, and most participants returned to baseline within about two months.