Winning three silver medals at age 41 in 2008 made Dara Torres the oldest Olympic swimming medalist.
She has won a record-tying 12 medals overall.
Now Torres is training for one her sixth Olympics in 2012.
"It's kind of fun to have the challenge of it to see if I can do it or not," she says.
"I always enjoy challenges. It's different this time because I don't feel like I have anything to prove. I'm doing it for myself."