Serena and I have done some great career planning, and we're playing really at the peak of our tennis right now. I think tennis has been a sport where people play this insane schedule from 14 years old, so of course at 26, it's over. We've really paced ourselves.

The most fun part about working out is being done - getting through the workout, let's be honest. But that feeling afterward? Yeah, that's worth it.

I don't carry a purse when I fly because I have my Hello Kitty carry-on. I'm the biggest adult supporter.

In the sports arena I would say there is nothing like training and preparation. You have to train your mind as much as your body.

Whatever it is, people have issues and that affects you deeply. So you have to get to the bottom of it and not let that affect your life decisions and really understand why you're making the decisions you make so that way you can understand how to not do that, so I always encourage people to ask why and then to really understand you, because that's the only way to be your most successful and your most happy.

It's amazing when tragedy strikes, how strong you find that you are, and I'd seen other people go through horrible things. And I just thought, "Wow, I would be a complete mess," and then suddenly when it happens, you realize you had more strength than you knew and it helps you to get through.

The principle of the design - the harmony, rhythm and balance are all the same with interior and fashion design.