When your body is screaming and depleted and telling you, “No way, asshole,” you work harder and tell yourself, “Do it. Now.” You control your body, it does not control you. You shut out the fear and emotion and physical stress and you do the thing you dread. You don’t go through the motions and watch the clock until it’s over. You invest in what you started, pushing yourself again and again beyond where you’ve already been.