Rihanna has revealed that it takes a lot of hard work to maintain her enviable rump.

The Umbrella singer says she stays in shape by exercising with a personal trainer and eating a high-protein diet.

However, she insists the end results are worth it.
 
Of her ample rear, she tells News of the World's Fabulous magazine: "I keep working at it as I want it to be perfect.

“It makes my clothes look good – and guys like it!"

It’s widely rumoured that Chris Brown is currently reaping the benefits of Rihanna’s tough booty regimen.

Click here to see Rihanna flaunting her favourite asset on stage.