I think, la tour de france, is THE competition of endurance. Its 3600 km, 21 days of continuous cycling. And the guy who won, Lance Armstrong, had to ride for around 86 hours... Man, if I had to ride for 86 hours on a bicycle, I would have my ass split into two, and hanging down like little puppies. (ok... thats a gross imagination)
Lance Armstrong, rode the bicycle, for 20 days every year, in tour de france, and won it for seven times. And they debate, if he is an athlete or not. They say, "He just rides a bicycle!!!"
The meaning of the word athlete, as per Dictionary.com
A person possessing the natural or acquired traits, such as strength, agility, and endurance, that are necessary for physical exercise or sports, especially those performed in competitive contexts.
Every trait of strength, agility, and endurance is being tested, in a competitive context in the tour de france.... And if that man who survived cancer, and won it all, is not an athlete with a single testicle, I don't know who is!!!
The origin of the word athlete, is from the Greek word athletes, meaning contestant... For me, any competitor who inspires the rest of us, in his moment of greatness, with his ability to extend the human limits - is an athlete.