(Cover) - EN Showbiz - Kelly Clarkson admits that exercising is "not all fun."

The 29-year-old Stronger singer lost a significant amount of weight before the debut of her upcoming TV show Duets.

Kelly has worked extremely hard to trim off the excess pounds.

"I call her Chuck Nora. She's my trainer. I stole her from my boyfriend," Kelly told Extra. "A lot of things are scheduled for me we go hiking, and it's not all fun. It's work."

Kelly has spoken previously about how her beau Brandon Blackstock keeps her motivated to stay in shape.

"I have a boyfriend, and if I'm being completely honest, no one likes to be not toned when you are dating someone," she told People magazine recently. "I tone whenever I want, and I chose to now because my boyfriend and I are both really into it But we don't work out together."

Kelly is judging alongside Sugarland star Jennifer Nettles, soul sensation John Legend and singer Robin Thicke on Duets.

The show's season premiere will air Thursday May 24. (C) Cover Media