As it turns out, it's actually a pretty concentrated effort on the pop star's behalf.
In a new interview with the Las Vegas Review Journal, Britney admits that she is a "character" on stage that she has to work hard to present and maintain throughout the show.
She said that the lights and everything add a couple of pounds, so she has to really focus on maintaining correct posture and such so that she looks like the Britney we all know and love.
"But like halfway through the show, you kind of lose your train of thought and you kind of let yourself go and you let it all out and then you don't look as good," she added. "It's about having a consistency with your character throughout the show. Keeping that character. Which is actually a little bit harder than what you think when you have so much going on."
Still, she admits that she set the bar pretty high for herself in her early career and it's hard to compete with that.
When she's not on stage portraying the picture perfect pop star, Britney works hard on her inner self and who she's becoming as she matures.
"As we get older, we need therapy," she admitted. "So I think it's a really good transition for me."
Britney's Las Vegas residency kicked off on Friday, where she performed in front of a star-studded crowd, which included celebs like Miley Cyrus, Selena Gomez and Katy Perry.
Her boyfriend, David Lucado, was also in the audience.