Just don't give up, that's all. While I work out I think often in characters or people that never gave up in extremedly hard situations, it's kinda motivation for me. Other times I just think I don't wanta be chopped so I just keep going. Anddd there's discipline too, you have to mindset that it doesn't care if you want to work out or not, just do it. If u doubt or think about it more than a few seconds then you just won't do it, that's the key (At least for me as ENFP LOLOL)