The Rock called Kerr a "unicorn athlete," before adding: "I had to transform my body, which was a massive challenge for me. But this is the kind of muscle that you have to put on that has real fast-twitch fibers to it." In The Smashing Machine, The Rock plays the role of one of the most iconic MMA fighters of all time in Kerr. While The Rock went to great lengths to become the best version of Kerr possible, he has already transformed his body again in anticipation of his next role. According to Parade and US Weekly (h/t Megan Cartwright of Newsweek), The Rock has shed 60 pounds in anticipation of his next movie.