Britney Spears Shape Magazine Cover

Britney Spears may enjoy some KFC every now and then, but she clearly finds time to work it all off!

The 31-year-old mother of two flaunts her amazing stomach in a white bikini on the cover of Shape magazine, where she opens up about her fitness routine.

"I'm doing 90 minutes of yoga twice a week in addition to a lot of cardio — hour-long sessions three times a week with my trainer, Tony Martinez," she tells the mag.

The singer also uses Nutrisystem and has shakes for breakfast and lunch.

Spears, who has a gig coming soon to Las Vegas, briefly talked about the Sin City show.

"The performances won't be simple," she says. "They'll be a massive party from start to finish. And to pull this off, I have to be in top condition and running at full speed."

See how Brit Brit's bikini bod compares to other celebrity physiques above!

Hot Videos