The Role: King Leonidas in 300
The Technique: The whole film has Butler in nothing more than a cape and some pants, so he needed to be flawless. Mountain climber and conditioning coach Mark Twight bulked the stars up.
The workout involved pull-ups, deadlifts, pushups and flipping tyres. Once Butler was done with his co-stars, he'd then do another training session on his own. We need a sit down after hearing all that.
Did They Keep It Up?: He's not a real Spartan, you'd be mad to keep a training regime like that up.
The Role: Derek Vinyard in American History X
The Technique: High protein and strength building exercises were the order of the day to get Ed from being a weak looking skinny fella to a neo-Nazi prison worn warrior.
Did They Keep It Up?: Not really, Norton had to split his personality into himself and Brad Pitt to start fighting anyone in Fight Club . He still threw his own punches around though.
The Role: Cameron Poe in Con Air
The Technique: Weight-lifting weeks prior to the film and during production along with a strict diet to cut down his body fat resulted in the toned physique you see on screen.
Did They Keep It Up?: Cage peaked at Con Air in terms of his physique, despite being cast in numerous action films, nothing has got close to the prison hardened Cameron Poe.
The Role: Muhammad Ali in Ali
The Technique: The artist formerly known as the Fresh Prince got Sugar Ray Leonard's former trainer on board and through six-hour-a-day workouts and weight-sessions, he gained 35 pounds.
Did They Keep It Up?: If his physique in the likes of I, Robot and I Am Legend are anything to go by, he's certainly kept some of it up.
The Role: Randy "The Ram" Robinson in The Wrestler
The Technique: Rourke saw this as his comeback and threw himself into training, putting on 30 pounds of muscle whilst training with wrestler, Afa the Wild Samoan.
Did They Keep It Up?: Not long afterwards, Rourke appeared in Iron Man 2 where he is similarly stacked. He's also looking to play Welsh rugby star Gareth Thomas, where he'll need to bulk up.
The Role: Sarah Connor in Terminator 2: Judgement Day
The Technique: Hamilton used the same personal trainer that Ed Norton used for American History X , losing 12 pounds and doing six hours a day, six days a week.
There was everything from weights, running, swimming, trampolining and lunging. Check the chin-up scene for proof of where the work went into.
Did They Keep It Up?: After the movie Linda Hamilton apparently chilled out a bit, only training five days a week, because, y'know, that's chilled.
The Role: James Bond in Casino Royale
The Technique: Craig opted for a lot of circuit training, which is useful for losing fat and building muscle at the same time.
Did They Keep It Up?: Not as much. In an interview about Quantum of Solace, Mr Craig said, "Last time I did a lot of weights to bulk up. This time I'll do more running. I won't be as "no-neck"."
The Role: Achilles in Troy
The Technique: Pitt said in an interview, "The first three months were daunting and not fun at all." He did two to three hours in the gym with high-protein and low-carb meals.
Did They Keep It Up?: We can't be sure whether he kept up the exercise as much, but he must have kept something up to bag Angelina Jolie only a year or so later.
The Role: Dastan in Prince of Persia: The Sands of Time
The Technique: Gyllenhaal's trainer Simon Waterson was with Jake for around a year 24 hours a day, seven days a week.
He said in an interview with PopEater, "I made sure he trained when he need to train. He was fed when he needed to be fed. And rested when he needed to rest."
Did They Keep It Up?: He's noticeably less ripped in Love and Other Drugs , his follow-up film, but not by much. Something must have stuck.
The Role: Charles Bronson in Bronson
The Technique: The film stopped and started, speaking to IndieLondon, Tom Hardy said, "I actually put the weight on a year before and then it fell through, so I lost it again for Stuart: A Life Backwards . And then I came back and had five weeks to put it on."
Did They Keep It Up?: Hardy is dedicated to his roles, so he'll fluctuate in a similar fashion to Christian Bale and he's got even bigger for his role as Bane alongside that man in The Dark Knight Rises.