Tired already? An exhausted looking Britney Spears emerges from rehearsal ahead of her Las Vegas residency

With the countdown now on until Britney Spears takes the stage in Sin City, the star is working around the clock to be ready.
The 31-year-old emerged from rehearsals in Van Nuys, California, on Thursday looking a little worse for wear.
The Hit Me Baby One More Time singer has been in the studio preparing for her Las Vegas, Nevada residency.

Had better days: Britney Spears emerged from rehearsals in Van Nuys, California, on Thursday looking a little worse for wear

Britney better get used to feeling overworked as the multi-million dollar performance schedule with Planet Hollywood Casino will see the pop star take to the stage almost
daily show for two years.
However, on Thursday Britney did not look like she had another hip shake in her as she walked out to her convertible flanked by a security guard.
Obviously trying to keep her energy levels up, the mother of two - Sean and Jayden - sipped away on a large iced coffee and carried a bag of takeaway treats from Starbucks.

Just the start of it: Britney better get used to feeling overworked as the multi-million dollar performance schedule with Planet Hollywood Casino will see the pop star take to the stage almost daily show for two years

Well deserved: Obviously trying to keep her energy levels up, the mother of two - Sean and Jayden - sipped away on a large iced coffee and carried a bag of takeaway treats from Starbucks

With so much time going into practice, the star is forgoing vanity, just throwing her unbrushed hair into a ponytail.
The singer also dressed for comfort wearing just a pair of baggy grey sweatpants with a sheer pink tank over a bright sports bra.
While tired, Britney has revealed she is excited for the 90-minute show that will feature both old and new hits and is set to begin on December 27.

No time to be fussy: With so much effort going into practice, the star is forgoing vanity, just throwing her unbrushed hair into a ponytail

Britney usually shies away from publicity these days the singer told Good Morning America that she already loves Vegas. 
The Toxic star said: 'The energy here is really, really good. I'm definitely going to do the greatest hits, but I'm going to have to put some of my new material into it just to keep it fresh.'
Britney is also busy promoting her new single, Work B**h from her upcoming album.
The star told fans this will be a very special CD tweeting: 'This next record is going to be the most personal record I've EVER made….which means that I need my #BArmy to be a part of it!!'

Not just the show: The 31-year-old has also busy promoting her new single, Work B**h from her upcoming album