Ramirez, who portrays fighting legend Roberto Duran in the film, had no prior boxing experience before he was cast in the movie, which also stars Usher as Sugar Ray Leonard, and so he had to work extra hard to look the part.

Duran took the actor under his wing and taught him a few moves and de Armas, who plays the boxer's lover in the film, admits she was very impressed with Edgar's commitment to the role.

"As a witness I have to say that it was an amazing, inspiring, beautiful process to see," the War Dogs star tells WENN. "Edgar, in the beginning, he had no idea about boxing. He couldn't even punch a bag in front of his face! It was amazing to see his transformation into not only a boxer, but he became Duran.

"He had the feeling and the energy and the moves and the spirit. It was not just his body transforming. It was a crazy thing to see. I was there in the corner throwing water on the towel and helping out."

And Ramirez reveals his co-star was a big help in the gym for one particular gut-wrenching workout: "She was stomping on my stomach," he says.

"So many boxing trainers do that with featherweights and with the flyweights. But I had the privilege of Ana De Armas doing it on me! One false move it could've been over but at least I would've been in heaven doing it."

The two Latino stars enjoyed some torrid lovemaking scenes on the set, with de Armas baring all for one steamy sequence.

"We had fun," she giggles. "We were just playing. I think we were shooting for like an hour. We were improvising that love scene for an hour! Until the memory card was full... Plus, he (Ramirez) was looking so hot he didn't care."