Heidi Montag: ‘I Worked My Butt Off’ For Playboy Cover

'I worked out very hard for this,' the 'Hills' star said of getting camera-ready for the men's magazine.

Heidi Montag and hubby Spencer Pratt both officially debuted Heidi’s September Playboy cover on the red carpet for “G.I. Joe: The Rise of Cobra” on Thursday (August 6). And now the “Hills” star, who played coy about confirming the photos earlier this summer, is revealing how she got Playboy-ready for the shoot .

“I worked out very hard for this,” Heidi told Access Hollywood, while plugging her Web site and her fitness routine. “I worked my butt off. [Playboy] kind of had a vision … and we brought in Matthew Rolston, who is a very well-known amazing photographer,” she explained. “So, it’s more art.”

Although some husbands may be jealous over their wives appearing in Playboy, Spencer couldn’t be more proud to see his on the magazine’s cover, clad in a white bikini. “See her powerful curves,” Spencer said. “They are powerful! It’s an honor. I feel like I did something great, like I should get a trophy!

“[The photos are] beautiful art,” he continued. “Not, like, Picasso art — real beautiful art, you know what I’m saying?”

The magazine may also be the ultimate gift for Spencer, as it hits newsstands on his 26th birthday. “It comes out on [Spencer's] birthday,” Heidi said. “August 14. Happy birthday, hubby!”