Jared Leto said the physical toll of playing WeWork founder Adam Neumann in the new series about the businessman left him “physically in pain”.
The Oscar-winning actor, known for his committed character performances, said the role was “excruciatingly challenging” because it required him to talk almost constantly.
WeCrashed tells the story of Israeli businessman Neumann and his wife Rebekah Neumann, played by Anne Hathaway, and their co-working space enterprise.
Their business developed into a global brand worth 47 billion dollars (£35.7 billion) in under a decade before plummeting in less than a year.
Speaking to Zane Lowe on Apple Music, Leto said: “I got to tell you, on this project, man, there wasn’t a day that passed by, and I was buried in dialogue… Adam talked a lot.
“And he’s the CEO. It’s his job. And he would talk strongly and with passion and with purpose. And every day I was just wiped out, physically in pain.
“And, really, just an excruciatingly challenging role. But there wasn’t a single day that went by that I wasn’t just acutely grateful to be there.
“I never wanted it to end sooner. And it was just awesome.”
Leto, who is also frontman of rock band Thirty Seconds To Mars, is known for his on-screen transformations for films such as House of Gucci and Dallas Buyers Club.
He also offered an update on new material from his band, in which he performs alongside his brother Shannon on drums, saying they had written nearly 200 songs during lockdown.
“As challenging as that time was for so many people around the world and devastating for so many, there was also a flip side to it,” he said.
“And for both my brother and I, I think it was like the universe doing for us what we can’t do for ourselves sort of thing, where, really, it was the first time we were in one place for that long since we were little kids.
“And even as little kids, we moved around as we had the kind of vagabond hippie life. And it was a blessing.
“And I sat and I started writing. It took me a month or two to get into the swing of things, but I wrote about 200 songs.
“And we have maybe two albums’, maybe three, worth of material. And we’re going to start putting it out momentarily. I mean, really momentarily. So really excited.”