Which has been your favorite Olympics? Lindsay Mulford SADDLE RIVER, N.J.
At my first one, being 17, I was in awe of everyone else, thinking, Oh, wow, there's Michael Jordan and Mary Lou Retton, and sort of forgetting that I was there as an Olympian too. I'd have to say this past Olympics [has been my favorite], only because as a 41-year-old you appreciate things more.
Which do you enjoy more, training or competing? Dave Brown EL SOBRANTE, CALIF.
Definitely competing. I would love not to train--it just wears and tears on your body. But the competing part is just fun. I get such a high standing up against these girls and racing them and just seeing who's the best. And to swim in the Olympic Games--there's nothing that beats that. It's just a thrill.
What diet do you follow to stay in shape? Samuel B. Mankins COLUMBUS, OHIO
I don't really have a diet, because I did have an eating disorder in college ... It was a very, very dark time in my life. It took about five years to get over. Now I just try to eat healthy. I try to eat my vegetables and my proteins. I like dessert. Maybe that's why I'm still swimming--because I can eat whatever I want.
What encouragement can you give to a housewife who wants to start a career at age 41? Saswati Biswas SHAWNEE, KANS.
Go for it! I don't think you should let your age stop anything you want to do. That's one of the messages in my book: Don't put an age limit on your dreams.
Do you believe you can be just as competitive as you are now when you reach 50? Michael Schmim ROCKFORD, ILL.
I think I'll always be competitive. In fact, I feel like I'm more competitive now than I was in my 20s. I spoke to the national-team coach, and he was like, You're the fastest American there is, and you're less than a tenth of a second off the world record. You should swim. And I was like, Yeah, he's right. I haven't reached my peak yet.
What do you think of Michael Phelps' marijuana controversy? Addison St. Onge-May PORTLAND, MAINE
Michael's young, and everyone makes mistakes. The biggest thing that he did was, he admitted it. A lot of people don't do that. We texted recently, and he seemed like his old, funny, kid self.
How do you respond to questions about performance-enhancing-drug use? Russell Granruth, BEL AIR, MD.
Bottom line: I've allowed myself to be tested any way there is to be tested. I've passed the drug tests. So there's not really much more I can say. If anyone asks me about those things, I guess I'll have to take it as a compliment, because they think I'm that great a swimmer that I'm cheating to swim fast.
Can you give me any advice for my swimming career? I'm 8 years old, and I have been on a competitive swim team for 2.5 years. Eva Wilk, DALLAS
When I was 8, I did other sports also. The one thing I would tell you is, Don't limit yourself to one sport for the rest of your younger years. It can get monotonous, and you can burn out really quick.
How did you juggle the demands of new parenthood with the intense training required to prepare for the Olympics? Kimberly Britt WINTER PARK, FLA.
When I got back into swimming, I can't say it wasn't hard, because it was. I felt guilty. I would call the nanny every 10 minutes. What I do now is, I get my daughter involved in what I do. And that really helps out a lot.