it is easy to take care of my body.

*Easy* usually means the friction got removed, not that the will got stronger.

Sneakers by the door instead of in the closet. A water glass already filled on the desk. The pool on the way home rather than a detour. None of that is discipline; it is a floor plan.

People who look effortless about this have generally just arranged their lives so the good option is the nearest one. That is something you can build an inch at a time, and it holds you up on the days you have nothing else.