When Anne Hathaway wanted to get into killer shape for her upcoming movie, 'Bride Wars,' she turned to celeb trainer David Kirsch, who's also honed the bods of ferosh celebs like Heidi Klum. In the new issue of Glamour, on stands Aug. 5, David and Anne reveal his fat-busting tricks, like oblique crunches and something called the "platypus walk"?

It "lifts the butt up a good inch higher, working the inner thighs," he says. 

To give Anne lean legs, David says he had her do 15 plié toe squats, lifting heels off floor while feet are turned slightly out, along with single-leg dead lifts, a standing move where you raise one leg behind you, and switch lunges, a tricky sort of jumping lunge.

"She really wanted to sweat," he said of her determination. "It de-stressed her."

The founder of the Madison Square Club and author of the Ultimate New York Body Plan, David also helped re-sculpt Heidi's post-baby tummy. For Heidi, he recommended numerous reps of oblique ab crunches and mountain climber reps, using a medicine ball and alternating legs in a push-up like position. 

But his craziest exercise is the platypus walk, a squat-like walk done while holding a medicine ball over one's head.

For more of David's star workout tips and fitness supplements, pick up Glamour magazine or visit www.davidkirschwellness.com.