Usher had to shed the pounds for role in 'Hands of Stone'.
The 37-year-old singer-and-actor appears in the boxing biodrama - a biopic of ring legend Robert Duran - as Sugar Ray Leonard and admitted he prepared for the project by focusing on the sporting aspects of the film, rather than as an actor.
He told 'Today': "I had to lose weight. I cycled. I even had to change my eating habits to eat for my blood type. I worked out three times a day sometimes - I had a trainer in Atlanta, Georgia, Xavier Briggs and I worked out at Gleason's Gym here in Brooklyn and in Philly. But I didn't prepare like it was an acting role - I prepared like I was a boxer."
He revealed filmmakers offered him the role because they saw similarities in him and Sugar Ray Leonard.
He explained: "There were some similarities in the way that we looked - other than just being black - it was definitely a buoyant nature and also the ability to choreograph and understand movement the way that I did...I pretty much know what I'm going to do before I hit the stage and Sugar Ray did as well.
"It was a very aggressive role because there was so much tension between Sugar Ray Leonard and Duran and a great deal of intimidation went into all the fights and their exchanges, so outside of the ring time our acting roles was a bit intense."
In the movie, Usher appears alongside Edgar Ramirez as Duran and 'Goodfellas' star Robert De Niro as his rival's trainer, and had an "amazing" experience.
He said: "I have [done acting before] but none like this, I actually didn't have as many scenes with De Niro - I had more scenes with Édgar (Ramírez) It was fun, it was amazing."
But Usher, who took the role seriously, almost didn't accept the film offer.
He said: "I didn't want to accept the role without the permission of Sugar Ray Leonard so I reached out to him - he's an American icon, an Olympic medalist whose well decorated and celebrated."
Speaking about why it was important he met Sugar Ray Leonard, he added : "I wanted intimate details about things I'd read in his book 'The Big Fight' and after that he trained me, he worked with me, I wanted to make sure that I represented it the right way.
"This is an amazing film that in many ways represents the pride of Latinos and I'm so happy that Sugar Ray Leonard was able to be a part of that. It is Robert Duran's story but Sugar Ray Leonard was definitely a part of that story. It's going down in history."
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