The 41-year-old actor did his own stunts in the film and says swimming in water was the toughest challenge, reported Femalefirst online.
"For all the stunts I was well prepared. But the water? Below 32 degrees? There was nothing I could do to prepare for that. And it freaked me out. Let's just say it wasn't very pleasant," Renner said.
However, the actor found the action scenes in the film to be a piece of cake.
"Those scenes are like a well-oiled machine because they have to be smooth, fast and vicious. Of course, if you're doing hand-to-hand stuff, there are going to be black eyes. I had to give a few," he added.
