Why did Anna Kournikova join TV's Biggest Loser?
—Sven Nyquist, St. Paul, Minn.
When the former tennis pro was asked by producers to be a trainer for The Biggest Loser, she knew she could help motivate the overweight contestants. "I knew I had all the knowledge," says Kournikova, 30, who ranked 8th in the world in 2000 as a solo player but was ranked No. 1 in doubles with partner Martina Hingis. "The last few years have been more relaxed for me, but it definitely was very easy to jump right back into being super disciplined, dedicated and spending a lot of hours and time with these people, trying to really change their thinking and mentality."