Natalie Portman’s ultra-slim silhouette in the new movie `Black Swan' has created a buzz over ballet. Known for creating flexible, lean and toned bodies, “ballet builds terrific posture and body awareness, and can also be a lot of fun,” says Mary Helen Bowers, the professional ballerina who trained Portman for her role. “Ballet dancers are also unbelievably strong, but their muscles are very long and lean.” We don't recommend you follow Portman's character's eating habits. But ballet workouts, combined with a healthy diet, can be great for your body. We asked some of the nation’s top instructors for ten of their best fat-blasting moves.