The Iron Claw’s Zac Efron wrestled 20 matches in a day as Kevin Von Erich

Zac Efron didn’t just look the part as hulking heavyweight Kevin Von Erich in wrestling biopic The Iron Claw – he even stepped into the ring and ran the ropes as a wrestler-in-training.

"The wrestling matches we would shoot start to finish," Efron tells GamesRadar+ of his intense filming for the role, which recreated some of the Von Erich clan’s legendary matches from the 1970s and 1980s in front of a real, live audience.

"Some of the earlier matches were 15 minutes long and we were doing those for five-to-seven wides, same for medium [shots], then similar for close-ups and specials."

Efron added, "A lot of those matches turned into 20-match days. They were quite gruelling, but also really fun. It felt authentic. It felt real. I love that process, it was really fun."

Director Sean Durkin revealed that getting his actors into the ring and performing in front of a live crowd made a "big difference" to their performance.

"They were not just a great crowd, they were a really lively crowd. I wasn’t expecting it," Durkin says. "The first day we started working, it was just electric and the guys could feed off it in the ring. It just gives that little bit of extra adrenaline and it really made a difference."

Efron was also acutely aware that pulling apart the complexities of playing a wrestler – a unique profession that 'lives the gimmick' 24/7 – required an immense amount of physical effort, something which ultimately aided him in playing Kevin Von Erich.

"I think that’s one of the fascinating things about wrestling. Sean talks about this really well, but the sport really hasn’t been examined because it’s so intricate and there’s so many different facets to it," Efron observes.

"There’s the real person and the character, there’s also the persona and the physicality that they take on in the ring. So, yeah, there’s a lot. I think the preparation for this helps a lot. [By] becoming Kevin physically, I was able to wear that through the filming process – and that helped tremendously."

The Iron Claw hits UK cinemas on February 9. 

For more from our chat with Zac Efron and Sean Durkin, be sure to dive into what they thought of the biopic's Oscars snub.