Kelly Clarkson's Secrets to Staying in Shape

With her new tour kicking off on June 30, pop superstar Kelly Clarkson is looking for ways to stay in shape. That's not an easy task when you have a super-busy schedule, but the Texas cutie and inaugural American Idol winner manages to get it done.

"I do kick-boxing, I run bleachers, I have to keep my endurance up or I won't make it through a show! My songs are marathons," Kelly told the Yahoo! Insider.

 

Her other secret to maintaining a hot bod? Banning soda.

"I was really bad with Cokes," Clarkson said. "I had, like, nine Cokes a day. Now, if I have soda, it ruins me. It almost tastes like acid."

She's so passionate about eating well that she's hooked up with Glacéau's vitamin water beverages on a new ad campaign - one designed to get kids to kick their soda and junk food habits. Clarkson remembers going to public high school and eating in the pizza and burrito cafeteria lines.

Nowadays, she's singing a different tune and encouraging teens to eat healthy by serving as a judge for the finale of "vitaminschool," a recipe contest for students.

The contest recently awarded a $100,000 college scholarship to a high school girl whose healthy school lunch recipe -- a chicken fajita burger on a whole wheat bun -- won top honor.

"Kids aren't paying attention, so why not give them a healthy option," Kelly said. "I have a lot of young fans, so that's why we teamed up. I realize there's a lot of people looking at me and if you have a voice, you might as well make it a positive one."

At 24, Clarkson has already won two Grammys, two American Music Awards and 11 Billboard Awards. Her "Addicted!" tour opens at the end of this month in West Palm Beach, Fla., and will hit 25 cities by August. She'll be singing smash hits such as "Behind These Hazel Eyes," "Because of You" and "Since U Been Gone," without any lip-synching, thank you very much.

We're looking at you, Ashlee Simpson.

"I just think that's ridiculous," Kelly says. "People will come up to me and be like, 'Why do you do two shows and then take a day off?' And I say, 'Because I'm a singer!' I won a singing competition. If you need to lip synch, if you're that ill, take a day off!"