I find many athletes throw around the word, "burnout", or some variation of it. Many talk about it like it is a disease to avoid, which could send your life into an abyss. The truth is, many athletes never approach actual burnout, where it would truly affect them for years to come. Burnout gets a bad rap, and many athletes don't realize how valuable risking burnout is.
It's likely that many reading this blog are beginning to get excited for the 2013 season, and near the end of last season they were ready for the end of it. That's not burnout, but it does show an emotional commitment. True burnout is when you've committed to the point where you just can no longer commit to the same level as in the past, for good.
Simon Whitfield used a common phrase in his build-up to Beijing, "Be obsessed." It paid off, as after winning Olympic gold in 2000, he had a rough race in Athens 2004, before riding that obsession to a silver, (nearly gold again), in Beijing. It takes a level of obsession and commitment to reach your potential as an athlete.
In the end, when I hear athletes speak of a fear of burnout, that usually means they are scared to reach their potential, because the commitment level required to reach their potential means a risk of burnout. When the commitment level is that high, it is hard not to succeed.
To walk away from the sport due to burnout likely means you've come very close to meeting your potential, and that should feel a lot more satisfying than walking away and feeling like you could have given more than you did.
In short, don't fear burnout...risk it.