It's helped me immensely to move from a moralistic "I'm procrastinating because I have a weak constitution" belief to an "I'm procrastinating because I set up the environment wrong" mindset.

It turns out that I get more done, run faster, and find both intellectual and physical work much easier when I've taken excellent (rather than merely okay) care of baseline needs like sleep, nutrition, exercise, and household chores.

Willpower as a finite but manageable resource is a much more useful belief than willpower as a character trait.