Excessive mental energy spent contemplating a task can be more draining than the physical activity itself.

“So, for for a lot of people, they get so tired of thinking about trying to go to the gym because thinking about trying to go to the gym takes more energy from them than actually being there, right? Because it's running around in their head how they failed and how bad they're going to feel and how they really want to do this and maybe they will and maybe they won't and there's so much going on inside of them that they're making something very very complicated.”