When thinking about the greatest actors of the last century, it's impossible that Robert De Niro doesn't come to mind. His films are timeless and have marked the lives of many, and his partnership with the incredible director Martin Scorsese is probably among the best duos in show business.

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De Niro is not only known for his breathtaking talent but also for his dedication to his profession. He is one of the most committed actors in the world, and is always guaranteed to give his all to any project he is in. That includes going to extremes to make sure he is on point to play his roles. In this article, fans will read about some of the most impressive things Robert De Niro has done to prepare for movies.

10 He Spent Three Months In Sicily To Prepare For 'The Godfather'

The Godfather is one of the most iconic movies of all time, starring the acting legend, Marlon Brando. The second installment of the trilogy is also one of Robert De Niro's most popular, though by the time he got the part of young Vito Corleone in The Godfather Part II, he was already a professional actor. As such, he took this important role very seriously. In order to get into character, he spent three months in Sicily learning the language, the accent, and the mannerisms from that region of Italy.

9 He Put On 60 Pounds For 'Raging Bull'

It's normal for actors to have to modify certain aspects of their bodies in order to fit the physique du role for their parts. However, Robert De Niro took it to another level. When he got the lead role for the timeless biographical movie Raging Bull, which earned him an Academy Award, he started a program of diet and bulking exercise to put on weight to play Jake LaMotta, a great boxer who had problems engaging with his family and friends due to his self-destructive habits. De Niro ended up putting on 60 pounds.

8 He Also Took Boxing Lessons

Another big sacrifice he made for Raging Bull was learning a new skill. One that was not at all simple. While he was preparing to play Jake LaMotta, he received professional boxing lessons by LaMotta himself. Needless to say, training with a professional boxer can't have been easy, but from what De Niro said, he actually got pretty good at it. He even competed in some fights himself after the movie. Working with Jake was intimidating, but the boxer made him feel comfortable and his training was certainly useful for the movie.

7 He Worked As A Driver For The Movie 'Taxi Driver'

In 1976, De Niro starred in yet another Martin Scorsese movie, Taxi Driver. His performance as Travis Bickle, a war veteran working as a taxi driver while struggling with his mental health, earned him an Academy Award nomination. This was not only because of his incomparable talent but also because of his commitment to the role from before they even started filming. In order to get into character, Robert De Niro worked as a cab driver for a few weekends.

6 He Lost 30 Pounds

Another part of his preparation for Taxi Driver involved looking accordingly to the character he was playing. Travis Bickle was suffering through mental health and financial problems.

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To prepare for the role, De Niro lost 30 pounds. Many might think it's not healthy to do such a thing for a movie, but the actor wouldn't put himself in harm's way, and surely did this with a proper diet and workout routine.

5 He Had His Teeth Modified For 'Cape Fear'

This is one of the most extreme things the actor has done for a role, but it seems to have paid off. For the movie Cape Fear, De Niro had to play a truly unsettling and despicable characters viewers have ever seen. Max Cady was a convicted rapist, who seeks vengeance against the lawyer that sent him to prison. To play him, De Niro decided to alter his physical appearance in addition to getting into his mindset. He had some very expensive dental work, in order to grind his teeth down and make himself look more menacing.

4 He Followed An Intense Workout Routine

To get in shape to play the insane and disgusting but very strong and agile sex offender Max Cady in Cape Fear, De Niro went through a strict workout routine that resulted in him reducing his body fat to an impressive 4%. To do this he hired a personal trainer and diligently exercised every single day, while also switching to a high-carbohydrate diet that gave him the energy he needed for his intense workout sessions while at the same time helping him get in shape.

3 He Used The Role Reversal Technique To Prepare For 'The King Of Comedy'

The role reversal technique consists of the actor trying to see the world through the position of the character they are playing. In The King of Comedy, De Niro portrayed a delusional up-and-coming comedian that is eager to find fame. He meets Jerry Lewis and becomes obsessed with him, to the point of stalking him.

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De Niro's preparation for this movie included turning the tables on his own stalkers. Nothing serious, but just making them feel the same way he does when they become too insistent with autographs.

2 He Observed Comedians Closely

Also for his role in The King of Comedy, De Niro decided to learn about comedians by observing them. He would go to many stand-up comedy shows to watch different comedians in the course of a couple of months, with the purpose of learning about comedic timing, about the length of the performances, and just about every general aspect of comedy. He had the opportunity of meeting Jerry Lewis before the movie, but he turned it down because he was supposed to hate him and he was getting into character.

1 He Traveled Around The Country To Research For 'The Deer Hunter'

For this movie, De Niro did one of the most dedicated and thorough researches of probably any other actor, showing once again his commitment to his craft. Especially considering that, during this time, he was working on other projects and was very busy. He was supposed to portray a mill worker, so he spent weeks traveling through the United States, learning about steel mills in different places and what the workers' shifts were like. By the end of his trip, he was ready to blow everyone's minds with his performance.

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