I decided to get fit and healthy a few months ago, and boy was I motivated and stuck at it for a week or two well, but I was pretty undisciplined and slipped pretty quickly. I had to essentially codify it into a quick routine, get up and do x, after x do y, when z is true etc. Amazingly treating it essentially as a programming task helped me stick to it more, because once I'd 'written' the routine in to my life it was pretty easy to just go through it every morning.

Motivation is a weird thing, we all start with the best intentions in the world but sticking with the good habits is damn hard.