There’s no doubt that when we pay a portion of our hard-earned money to watch the latest Hollywood film, we want the actors on-screen to be giving absolutely everything to their role.

But whilst we both love and admire a star’s commitment to giving us a truly authentic performance, there have been a number of occasions when individuals have taken things too far, occasionally to the point where they have risked their own health in the process.

Below are eight shocking examples of Hollywood actors who went way too far for one of their roles, the knowledge of which may mean that you’ll never be able to watch the film in which they starred in the same way again.

8. Sylvester Stallone (Rocky IV)

As much as we love them, many of the boxing scenes in the Rocky filmsdo look rather unrealistic, which is something that Sylvester Stallone and Dolph Lundgren were well aware of when shooting Rocky IV, the third sequel in the popular franchise.

During filming of one of their scripted fights, Stallone and Lundgren thought it would be a good idea to start throwing real punches. Unfortunately this quest for realism put Stallone in hospital for two months, after Lundgren punched Stallone so hard that it caused his heart to swell.

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7. Daniel Day-Lewis (The Last of the Mohicans)

Three time Academy Award winner Daniel Day-Lewis is well known for losing himself in the characters he portrays on screen, and this was never more the case than when he starred in Michael Mann’s 1992 historical epic The Last of the Mohicans.

Day-Lewis reportedly ‘lived off the land’ for the entire duration of the film’s shoot, only eating what he killed or found himself, and he even learned how to make canoes and throw tomahawks. Unfortunately, reports suggested that the actor struggled to leave the character behind after shooting had wrapped, and sought professional help after he started suffering from claustrophobia and hallucinations.

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6. Christian Bale (The Machinist)

In the most extreme case of film related weight loss that we’ve ever come across, Christian Bale dropped a quite staggering 27kg in preparation for his role as Trevor Reznik in the 2004 psychological horror The Machinist, and took only six weeks to bulk back up into the physique that he would sport for his debut performance as Batman in Batman Begins.

“I was intrigued by a perverse nature of mine just to see if I can go beyond what I’ve been told is actually safe and okay, and see if I could push the limits,” Bale has been quoted as saying.

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5. Martin Sheen (Apocalypse Now)

Do you remember the scene at the start of Apocalypse Now when Martin Sheen’s Captain Willard goes crazy and punches a mirror? Well, let’s just say there wasn’t a lot of acting involved.

Sheen, who was battling alcoholism in his personal life, was drunk when the cameras started rolling and punched a real glass mirror during what was him genuinely freaking out, causing him to start bleeding everywhere.

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4. Adrien Brody (The Pianist)

He became the youngest ever actor to win the Academy Award for Best Actor, and Adrien Brody ensured that his performance as Holocaust survivor Wladyslaw Szpilman in The Pianist was as authentic as it could possibly be, by completely losing himself in the role.

As well as dropping nearly 14kg in weight, Brody learnt to play the piano by practicing for hours each and every day. Not only that, but the actor has revealed that he completely left his life in the US behind, saying “I gave up my apartment, I sold my car, I disconnected the phones, and I left. I took two bags and my keyboard and moved to Europe.”

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3. Halle Berry (Jungle Fever)

Spike Lee believed that Halle Berry was too pretty to play drug addict Vivian in the 1991 film Jungle Fever, but this didn’t put Berry off, and the future Academy Award winner went to extreme lengths to ensure that she gave a realistic performance.

Not only did Berry research her role by spending time in a real life drug den, but she has also confirmed that she didn’t wash for two weeks before shooting started, saying “it’s true, ask Sam Jackson. He had to get a whiff of it!”’

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2. Robert De Niro (Taxi Driver)

The fact that performing in films requires you to act seems to have been lost on some Hollywood stars, with Robert De Niro’s preparation for his groundbreaking performance in Taxi Driver being a prime example.

Because rather than simply pretending to be a Taxi Driver in Martin Scorsese’s 1976 classic, De Niro actually got himself a taxi driver’s licence, worked 12 hour shifts for a time, and even picked up passengers during breaks in filming!

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1. Danny DeVito (One Flew Over the Cuckoo’s Nest)

Our final entry could actually apply to the entire cast of the Academy Award winning One Flew Over the Cuckoo’s Nest, because every single one of them spent time living in a real psychiatric hospital to prepare for the film’s shoot.

But we’ve singled out Danny DeVito, because the future Twins and Get Shorty star reportedly dreamed up his own imaginary friend during their hospital stay, even becoming convinced that his made up best pal was completely real.

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