Michael Phelps Photo by: Al Bello / Getty

Michael Phelps splashed down in the water this week for the first time since the Beijing Olympics - and says: "It was painful."

At his hometown pool in Baltimore, the swimming champ, 23, unveiled a new series of Kellogg's cereal boxes Thursday morning and admitted, "I'm a little out of shape. But I will be able to get back. I am going to start working out more."

Phelps, now sharing box fronts with Tony the Tiger and others, was presented a $250,000 check for his newly formed Michael Phelps Foundation, a charity aimed at promoting youth swimming.

His foundation remains Phelps's focus until he begins training for the 2012 Olympics in February.

"I think the little guys, the kids in the world, are going to be me in 10 years or so," he says. "So I'm just trying to promote a happy, healthy lifestyle."

His Love Life

While he wouldn't talk about his dating life, Phelps lit up when asked about Herman - his English bulldog - who lived with friends over the summer.

"I'm going to see him today," Phelps gushed.

Shy by nature, Phelps said fame has been a constant surprise. "It's different. It's fun. I'm enjoying the ride."

As for all the female attention he says, "I don't really notice it. When I go out, go to dinner, I go out with friends, and we stay to ourselves. I don't think of myself as a sex symbol. My mom is by far the most important woman in my life."