Does Gwyneth Paltrow have buns of "iron"?

The 40-year-old Iron Man star has been working on her posterior, and apparently it's been paying off, according to Us Weekly.

Gwynnie says she was trying on bathing suits, and she asked a friend how her behind looked.

"I said, 'You know, this isn't so bad for 40, right?'" Gwyneth says. "And [my friend] goes, 'It's not so bad for a 22-year-old stripper!'"

Ha! We're pretty sure that's a compliment, although it's certainly an unusual one.

Gwyneth says that trainer Tracy Anderson helped her improve her figure, even though the actress had initially been convinced that exercise wouldn't pay off as far as her butt was concerned.

"Oh, I knew it would never change!" she says. "I had exercised before I had met her... I had done Ashtanga yoga and pilates, and I [ran], and I thought I was fit, you know?"

But now, Gwyneth says she has seen the benefits of a rigorous exercise regimen  even if the process is not particularly fun.

"I just sob and then kick and scream, and then I just force myself to do it," Gwyneth admits. "I just got obsessed. When you see results like that, I started following everything she said, and she completely transformed my body, and I'm so grateful."

And apparently, if this whole acting thing doesn't work out, Gwyneth can get work shaking her moneymaker on a pole.

Source: Us Weekly