" That’s why just about every top professional athlete has been laid low by injury, sometimes a career-ending injury. There was a moment in my career when I seriously wondered whether I’d be able to continue competing at the top level. I play through pain much of the time, but I think all elite sports people do. All except Federer, at any rate. I’ve had to push and mold my body to adapt it to cope with the repetitive muscular stress that tennis forces on you, but he just seems to have been born to play the game. His physique—his DNA—seems perfectly adapted to tennis, rendering him immune to the injuries the rest of us are doomed to put up with. "