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As the mom of two growing boys, Britney Spears admits it can be hard to stay in shape.

"I love white chocolate, and I love potato chips! I like the salty and sweet," the "Toxic" singer and mother of sons Sean, 7, and Jayden, 6, recently told " Extra." "When the [the boys] come over, the snacks are constantly piling up, and I constantly have to feed them. I'm like, 'Jesus I want fried chicken too!'"

To counter her love for junk food, Spears, 31, sticks to a workout routine.

"I really love doing yoga. I have two separate trainers that come in and we play with it. I don't like doing the same thing all the time, but my main ritual is yoga. I do a lot of yoga," she told "Extra."

READ: Britney Spears Reveals Fitness Secrets

She's showing off the results of her hard work in a teeny white bikini on the cover of the June issue of Shape magazine.

In the magazine, Spears expounds on her exercise regimen, telling the writer that she does 90 minutes of yoga twice a week, as well as hour-long cardio sessions three times a week with her trainer.

One reason she's working so hard to stay in shape: a Las Vegas residency that will start this fall.

'The [Vegas] performances won't be simple … a massive party from start to finish," she told the magazine, on newsstands May 20. "And to pull this off, I have to be in top condition and running at full speed."