Carrie Underwood may have a figure any cowgirl would kill for -- but it doesn't come easy.

"This is an Underwood family tradition," Underwood, 26, jokes to "Extra" as she pokes her midsection. "The rear... starts going in and out so I have to work really hard to have it stay where it's supposed to be."

See photos of Carrie through the years

"Extra" caught up with the former "American Idol" champ as she prepares to host the Country Music Awards this Wednesday. Underwood revealed her tricks to stay slim before the ceremony.

"Get rid of the junk crap," Underwood says. "Lots of water and Vitamin Water -- it's got a lot of good stuff in it."

Check out photos of Carrie and other memorable singers on "American Idol"

Catch Underwood on "In the Spotlight with Robin Roberts: Bright Lights. Big Stars. All Access Nashville" Tuesday night on ABC.