There should be a scale in sport which can measure the magnitude of intensity. A sort of sporting Richter. We could call it the Nadal Scale. Because he's the standard by which we could measure everyone's competitiveness.
Desire isn't any particular athlete's prerogative, it's the essence of champions. They win with fever, hangovers, torn ligaments and a few months after giving birth. In an article in golf.com, Charles Howell III told stories about Tiger Woods competing to see who eats the most bagels. The competitive switch often has no Off position.