Hilary Swank's Hard-Core Workout

Hilary Swank just started work on her new film about Amelia Earhart. But she's already attracting attention for the smoldering hot body she's earned preparing for the role.

And E! News has the exclusive details how she did it:

Several times a week, Swank hits up Exhale, a Santa Monica workout studio where she's taking private instruction in "core fusion," a workout that combines the toughest elements of Pilates, yoga and ballet. It's a 60-minute workout that leaves the star dripping in sweat.

"She's just thrown herself into the workouts," says a source close to Swank. Though just as toned and fit as she was for her Oscar-winning role in Million Dollar Baby, Hilary looks leaner and not quite so "bulked up" as she was for her role as a boxer.

"Her stomach's taut, her butt's firm and high, all that stuff," said the Hilary source. "But she looks very petite and feminine. She's never looked better."

While we're not sure if Amelia ever had a bod that rocking, Hilary will mimic the famous aviator in another way, as we reported to you earlier. After each core class, Hilary pops off to the Santa Monica Airport, where she's getting her pilot's license.