Chris Hemsworth
Believe it or not, Hemsworth wasn't always a chick magnet. When he was young in his career, he wasn't in particularly great shape. However, when he was cast as Thor in the Marvel universe, he started training with a former Navy Seal trainer, and the results ended up setting him up for life.
The Superhero Treatment
Hemsworth teamed up with a man named Duffy Gaver, an old school trainer who prescribed Hemsworth with a workout regiment of lifting lots of heavy weights, and eating tons of red meat. After about a year of training, Hemsworth reached Thor status.