"I haven't had a cramp since '99. That was my only time, in Davis Cup, when I was panicky. I was young. I'm very proud of that. Never pulled out. Never had cramps. Never lost very much because of fitness, especially later on in my career where I knew I've put in the hard work. I've done that. I've been very fortunate and clever as well to understand how I need to work, when I need to work. So I'm very happy to have stayed injury free for so long. I hope I can still maintain a few good years on the tour. I really hope so."