It may not look like it now, but Taylor Lautner isn't a naturally strong guy. He became that way out of necessity. After all, between the first and second Twilight films, his character grew into a powerful werewolf. That meant he needed to gain 30 pounds of muscle in a year. Which he did, transforming his 5'10", 140-pound, teenage frame into a ripped fitness animal. You might say that going from scrawny to brawny was simply a brilliant career move. But he isn’t done yet: "My character continues to grow," says Lautner, who’ll step back into the role of Jacob in Breaking Dawn this fall, "so I'd like to pack on at least a few more lean pounds."