Miley Cyrus flies her personal trainer to wherever she is in the world.

The former 'Hanna Montana' star has recently revealed a new slimline look and sources close to the star say she is willing to pay any amount to keep it up, currently shelling out around $25,000 each month.

Miley, 19, currently pays her trainer $200 per hour but when she travels, she flies him first class so she can exercise whenever she wants.

Miley is quoted by National Enquirer magazine as telling a friend: ''I don't mind flying him wherever I am. It's worth every cent. I never thought I could look like this.''

One reason why the singer-and-actress is working so hard on her shape is that she is preparing for her wedding.

The star and her 22-year-old boyfriend Liam Hemsworth recently announced their engagement after the actor proposed with a with a 3.5-carat diamond ring from jeweller Neil Lane.

Miley said: ''I'm so happy to be engaged and look forward to a life of happiness with Liam.''

The 'LOL' actress also tweeted: ''life is beautiful.''

The couple met while working together on 'The Last Song' in 2009 and Liam has previously admitted while he wanted to be professional on the film, they couldn't help but fall in love after working so closely together.

He said: ''What happened happened, and we've been together since.

''She makes me really happy. When you start, you want to be professional, but when you're filming those scenes with someone and pretending to love them, you're not human if you don't feel something.''