Rachel McAdams spoke recently about her co-star’s stunning transformation (caution: spoilers ahead!) for Southpaw, saying that Jake Gyllenhaal really committed not only to the physical aspects of becoming boxer Billy Hope, but to the emotional ones as well. And while it’s clear that Gyllenhaal gave his all to the role, McAdams is earning praise for doing the same, even getting into the ring herself during filming to try and understand the sport of boxing a little better.

“When Jake was first starting to box, and I went and met him at the gym, he had a big bushy beard and a ponytail. Then, when I first showed up on set on day one, he was in the middle of shooting that first fight in the stadium. I was so unprepared and it was just amazing to get closer and closer to that ring and see him emerge and what he had done – not just the physical transformation but even his emotional shift was so palpable. He had become this person on a cellular level. So really extraordinary. Very awe-inspiring,” Rachel said.

Recently, the actress talked a bit about her part in the film and the transformation she had to undergo–which included hours in the makeup chair to portray Maureen–and revealed that it took hours to film her character’s death scene.

“I died for about seven hours. It was a very long drawn out death. The blood is pretty gross too. It’s like this red corn syrupy stuff,” McAdams said.

Gyllenhaal says he trained for about five months to achieve the right look for his character, and producer Peter Riche said that the goal for everyone was to make the film look as authentic as possible.

“The word ‘authentic’ was a word used every day all day. And it had to look different and it had to elevate boxing movies, so that was the intent — to show boxing in a way that you’ve never seen it,” Riche said.

Southpaw was written by Sons Of Anarchy creator Kurt Sutter and hits theaters on Friday, July 24.