Beyonce Knowles is nervous about going back to work since having a baby.

The 'Halo' singer gave birth to her and husband Jay-Z's first child, daughter Blue Ivy, in January, and while she is excited about her comeback performance at the Revel casino in New Jersey tonight (25.05.12), Beyonce is worried about returning to the stage.

In a just released behind-the-scenes video of her preparations, she said: ''I feel a little nervous. I'm enjoying being a mother so it's like going back to my old job, and it's a little strange. But it's important that you don't lose yourself and still have your own passions. And so I'm back to work, I'm back to business.''

Beyonce's choreographer Danielle Polanco also revealed getting the star back in shape is a challenge because she hasn't worked out in some time.

She explained: ''We're basically warming her up and getting her back into shape, Stretching her out . . she hasn't been working out in I don't know how long!''

Meanwhile, Beyonce admitted becoming a mother has made her ''more grounded'', which she aims to portray while on stage.

She said: ''What I'm trying to say in the show is, 'Yes I had a baby. It just made me more grounded and more like you.''