Zac Efron is upbeat as he promotes his new wrestling movie, The Iron Claw. After the première of the sports drama at The Ritz Carlton in Dallas, Texas, the actor, 36, joked during a press conference that the most severe pain he experienced in training to play pro wrestler Kevin Von Erich “was probably an ego one.”

“It was the very first time that I had to enter the Sportatorium in Kevin’s full costume, which was just, frankly, a Speedo, or trunks,” Efron recalled. “Everybody was out there, there was this huge crowd and the lights were on. I just remember in that moment thinking, how the hell did I end up here? What is going on?” He added, “In that moment, I was frozen in time just going: This is it. This is the end. How did you get here? What choices have you made?” In response, writer-director Sean Durkin commented, “We just wanted to celebrate you guys’ beautiful thighs.”