Brain tissue may be fuel for marathon runners

I'd like to see a follow-up to see how it's correlated to nutrition strategies pre and post race. The only info we have is that the subjects (n=4) were male and "well trained"[1], nothing I could find about their weight or body composition, or even how hard they ran their marathons!

[1] in the studies I've seen "well trained" usually means a VO2 max >= 70 ml/kg/min but that would be quite a feat for the oldest participant at 75!

Dear body, please try to burn my belly before burn my brain.

Could just be dehydration:

>> [they] used water trapped between layers of myelin as a proxy for myelin content. More of this water indicates more myelin. But you can’t rule out the effects of dehydration, Bouhrara says. If runners are dehydrated after their race, their brain tissues may just be dried out.

So basically myelins are, besides being each neurons' personal caretaker, also the neurons' personal fridge.