Britney Spears is preparing for her show in Las Vegas which is set to open this fall.
She said she is doing extra workouts to keep her body in shape.
"I'm doing 90 minutes of yoga twice a week in addition to a lot of card - hour-long sessions three times a week with my trainer, Tony Martinez," she said. "The [Vegas] performances won't be simple - 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."
She also said she is using the Nutrisystem program to lose weight.
Martinez is having her do fun drills in the workouts so she doesn't get bored and turns on some of her favorite songs. Included are Whitney Houston's "I Wanna Dance with Somebody" and Bruno Mars' "Locked Out of Heaven.