When Christopher Reeve landed the part of Superman back in the late seventies, he had the look, the acting chops, and the charisma Warner Bros. was looking for. The only thing he needed to work on was his physique. Reeve stood 6 feet, 4 inches tall but weighed about 180 pounds. Not bulky enough. With only a few months until the first day of shooting the first film, Superman The Movie, he needed to train fast and hard. He needed a real pro. Enter Dave Prowse.
Prowse, a champion body builder, played the (physical) role of Darth Vader in the first three Star Wars films, and he was initially hoping to land the Superman role himself. Reeve got it instead. In a bit of irony, Prowse was hired to train Reeve in order to get him as Supermanny as possible in a relatively short period of time.
Christopher Reeve's schedule consisted of running in the morning, followed by two hours of weight lifting and another ninety minutes on the trampoline. In six weeks, he went from 175 pounds to 212 pounds -- pretty impressive!
In addition to an arduous training program, Chris was put on a strict diet: he ate steak for breakfast, lunch and dinner every single day!