"As a fighter, as an athlete in general, you have to know that you're going to peak for a certain amount of time," said the 26-year-old. "Eventually, you're going to start breaking down physically or mentally or both. You can only do this for so long. I don't want to be one of those guys who push their careers on and on. I'm going to be on top of my game for a short period, and when the time comes that I question how much I want it, I'm going to step aside and let the new generation in."