The 19-year-old "Hanna Montana" star flies him first class when she travels so that she can exercise whenever she wants, reported Contactmusic.
"I don't mind flying him wherever I am. It's worth every cent. I never thought I could look like this," Cyrus was heard telling her close friend.
The actress, who recently got engaged to long time boyfriend Liam Hemsworth, 22, is said to be working hard to look the best on her wedding day.