I been around pro pool players for many years, and yes some get burned out more than others. I think the travel takes more out of the person than the "play" does. its not leisure travel.
I was at dinner 2 nights ago with a pro pool player here in Germany, he leaves for China on the 10th and is back on the 21st. While one trip like that a year to go take pictures of the "Great Wall" might be fine, to go there to win, play at a high level, under the pressure, tight schedule, then off to vegas the week after China from Germany etc. That would get old real fast with me, especially wen your over 40. Now if your 23 like Judd and have a very understanding wife/girl(like I do) then its different.
after chasing flights, tourny meetings, managing your $$$, personal life, airport food, playing in top form-anyone would get burned out.
Now private jets like football players have and handlers carring your baggage and limo's to the suite at the hotel would help keep the "burn-out" factor lower,