This is an online exclusive story from ESPN The Magazine's Body Issue 2014. The Body Issue hits newsstands July 11. A complete list of athletes featured will be announced Wednesday on ESPN.com. Subscribe today!
The grass is a very big challenge for me. There are these low bounces and different movements, which is very difficult, especially for my height and weight. When the surfaces change and I start to play on grass, I start to feel it in the lower back and the lower hamstring. But I manage to move well. My first Grand Slam final was at Wimbledon, so I have no complaints about the grass.
It's not so bad that I can't touch my toes. But I'm not one of the most flexible guys. When you look at Novak Djokovic, you'd probably think he's made of rubber.
I have a mental coach. I think this is one of the parts of the game that not so many people talk about. I've worked with him for about five years now, and I think it's worked quite well. These days, tennis is about all the small details; if you can get 2-3 percent here and 2-3 percent there, it's just perfect.
I remember when Rafa [Nadal] was playing in shorts that were almost full-length pants. Now I'm the one who comes out and plays in the old-school short shorts. But I'm comfortable in them. I like to be in the position of doing something different.
That was the reason I got on social media. Tennis players need to be very focused and very intense, and I can show tennis players are not just hitting the little yellow ball and moving in between the white lines. I'm always trying to show my personality outside of the court.
My fitness guy sometimes makes fun of me. He says because of my legs and upper body, I'm two people in one. But being heavier down low, rather than up top, is what has been working in my case. The ideal plan would be skinnier and lighter legs and a little bit more on the upper body. But it's not something where you go into a store and say, "I want that."
No swimming. I'm not good at it. I do a lot of biking. I need that mileage and the long-distance stuff because tennis demands it. My fitness trainer is always trying to convince me to do an Ironman. I can probably run the marathon, I can make the 112 miles on the bike, but I will never swim for 2.4 miles. I will die after 100 meters.
I really loved the sweets. When I was a kid I had quite a problem with my weight. The good thing is that my parents caught it in the beginning; they didn't ignore it and let me become overweight.
Players take it seriously. There is a big team around every single player. Everyone has one or two tennis coaches, a fitness guy, then a physio. ... The level of the game is higher because of this reason.
It's much more of a mental game. Everyone just wants to beat you. You are a big target that everyone below you wants to hit, and you need to be ready.
I don't really feel that I'm getting older. Since I started playing, I haven't had any major injuries in my career, even as I'm in my 13th season on the tour. In team sports when you are injured, others can contribute more and everything is fine. In tennis, if you are injured, nobody is going to give you anything for free. So it's important to stay healthy.
Follow The Mag on Twitter (@ESPNmag) and like us on Facebook.