Before he knocked audiences on their asses with American History X, Edward Norton wasn't much more than a solid actor with a bad haircut and few decent flicks under his belt.
Then he stomped onto the screen as Derek Vinyard, a raging neo-Nazi skinhead with the kind of physically imposing look that would make most men cross the street. Norton didn't just have the cut biceps and chiseled chest of a typical Hollywood leading man, he looked like a guy who had spent some time lifting weights in the joint. So how did the scrawny Ivy Leaguer go from Yale grad to jail bird? A high protein diet mixed with strength-building exercises like squats and presses.
His coach Anthony Krotes put the emphasis on weight training with heavy weight and low repetitions. The result was 30lbs of muscle and a lean, mean look that perfectly suited his tough character in the movie.
(Source: Men's Fitness)