31-year-old Britney Spears shared her Shape magazine cover shoot with her online following yesterday (May 7) and she has now given fans another glimpse into the accompanying editorial.

She posted the cover via her official Twitter page last night and Entertainment Tonight put together a behind-the-scenes video segment about the shoot, in which the magazine's Tara Kraft opens up about interviewing the 'Till The World Ends' superstar for the feature and reveals her least favourite body part:

"For her, it's her derriere. Britney says that now she's in her 30s she does have to work a little harder to keep it perky and firm, but who doesn't?"

"She knew after doing yoga for 90-minutes two times per week and three hours a week spent with her trainer that she was in great shape and, let me tell you, the pictures prove it."

In the interview, Spears also opens up about her forthcoming Vegas residency and admits that she needs to be in peak physical fitness for the run of shows as they will be very demanding: "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.”