I know this is going to sound crazy, but I really love working out. I know that sounds sick to some people, but I didn't love it at first. It's become a healthy addiction for me. And like, now, if I'm watching TV on the couch I'm like, "Ugh, I could be on a cardio machine watching the same thing. " That's just now how my mind thinks.
The top fighters spar hard. They're really sparring for two reasons: One is to improve their technique, but the other, which is just as important, is to build endurance, toughness, and courage. They want to practice as realistically as possible so that when they go into a real fight, the transition isn't as jarring.