I would say different things on different days. It is really good to "find a key" to yourself. I found out that for me it may be reading a chapter from self help book, or watching an inspiring movie, or having a talk with someone. I feel that I control my body when I do a class in the gym.
As a Marine who served during Vietnam, "discipline." When you learn to ignor your body, your surroundings, or situations you are experiencing at any given moment, discipline of mind, body and spirit is the only thing that will carry you through "any" circumstance reality dishes out.