Why thinking hard makes you tired

It's no surprise that hard physical labor wears you out, but what about hard mental labor? Sitting around thinking hard for hours makes one feel worn out, too. Now, researchers have new evidence to explain why this is, and, based on their findings, the reason you feel mentally exhausted (as opposed to drowsy) from intense thinking isn't all in your head.

from Top Health News -- ScienceDaily https://ift.tt/rDZR2y6