Tomas Berdych

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.

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.

When I have a creative insight, there is a high. I think back in the day, I made music as much as I did because it made me feel so good. I think you could argue that there is a creative addiction - but, you know, the healthy kind.