Got beach plans but you're a little camera-shy?

Gossip Girl star Leighton Meester - one of several celebrities to share her workout tips with People magazine - swears by "a week of really great cardio" to flatten your stomach.

Sound too good to be true?

"It's the smartest thing you can do so you know if you're burning fat," Leighton Meester says. "Rotate three routines for 20 minutes each, like roller blading, biking, and running."

So, forget that hour-long reality show and get moving! Just make it back in time for Gossip Girl on Mondays...