Most of the time being a Hollywood actor is all about the glitz and the glamour, but occasionally actors have to go that extra mile to transform themselves for a role. Take a look at some of the most dramatic actor transformations ever seen on film.
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Universal Pictures
Russell Crowe has shown off his toned body in several roles over his career, including in "Gladiator" and Ron Howard's 2005 boxing drama "Cinderella Man," as seen here.