At first glance, you might see Hilary Swank on this list and think we have the wrong idea. She's not tough, you'd say, "Million Dollar Baby" was just a movie. You'd be wrong. When training for "just a movie," Swank packed on 19 pounds of muscle and bloodied a man's nose in a boxing match. After four-hour workouts, six days a week and a diet that consisted of egg whites and protein shakes, she wasn't just acting tough. She was actually tough.