As I’ve written about in other articles here, one of the things that will keep you disciplined over time is to have a purpose beyond an immediate, day-to-day grind is key to keeping you going when things get tough. I think that having a positive purpose, a goal you want to reach, and making measurable goals to those ends will make it a lot easier to keep at other disciplined habits. This is especially the case for things like fitness and working out, which come with their fair share of challenges including soreness and pain along the way.