Dean Karnazes is incredible. His story is inspiring to many and almost unbelievable to some. Still others believe that he is "just another self-promoting huckster." It doesn't really matter; it can't be denied that he is a superb athlete and among ultrarunnings finest. Sure, his book,
Ultramarathon Man might have a few boastful statements("At less than 5 percent body fat, my body is ripped like a prizefighter’s, nothing left to shed."), but he isn't lying. However, it's not like he's the "Lance Armstrong" of running; that yellow jersey goes to Scott Jurek(even more my hero than Karnazes for several reasons, but I'm ranting/raving about Dean here).
Anyway, if you want, you can form your own opinion; there is a lot of literature about him if you know where to look (uh, how 'bout the library?). I could go on for a long time, but what I want to point out is a quote from Dean Karnazes: "If you're not pushing yourself beyond the comfort zone...you're choosing a numb existence."