Physically, out there, there are so many fit players. I mean, the game has changed tremendously. Top hundred players, physically there is not much difference between No. 78 in the world and No. 2, 3, 1, 5. But it’s a mental ability to handle the pressure, to play well at the right moments, and that’s why I think there is a certain difference with top-10 players.

– Novak Djokovic, after he reached the quarterfinals at the US Open 2011

How much further can the science of training and nutrition improve an athlete’s performance? I wonder if we’re reaching the flat part of the curve over the next several years. The German, Karstan Braasch smoked cigarettes in his chair during changeovers and reached  ranking of 38 in the world in 1994. You don’t see that too much these days.

The next performance curve is probably the science of the athlete’s brain.