Serena and I, we don't have anything to prove ... we still set a very high standard.

I have been recently diagnosed with Sjogren's Syndrome, an autoimmune disease which is an ongoing medical condition that affects my energy level and causes fatigue and joint pain.

To be a well-rounded person and know what's going on in the world around you, to have a perspective outside of your sport, is important for every athlete. I'm blessed that our parents gave us that.

I try to update as much as possible. You don't want to be in the past.

Tennis is mostly mental. Of course, you must have a lot of physical skill, but you can't play tennis well and not be a good thinker. You win or lose the match before you even go out there.

I've learned about employee relations; I've learned about following your instinct. One of the biggest mistakes you can follow is not following your instincts, you know? A lot of times your instincts will tell you what to do if you have a good one. Now, if your instincts are terrible, then you ask for advice. But if you have good instincts, you definitely have to follow them, or else you regret them.

For years I felt that I didn't have enough stamina and then, four years ago, I felt like I was not getting enough air but I was diagnosed with exercise-induced asthma. The medicine for asthma never worked.