"Sons of Anarchy" star Charlie Hunnam is once again opening up about abruptly backing out of the lead role in "Fifty Shades of Grey" and admitted that the film would have been a "disaster" if he stayed on board.

The 34-year-old hottie chatted with Men's Health magazine about how he stays in shape but also provided some details about why he didn't want to play Christian Grey.

"I go into the gym and do 75 pull-ups, 75 clips, 150 squats, 150 pushups, and then 20 minutes of ab work," he told the magazine. "Done. It takes an hour, I'm in and out. I sweat the whole time."

"I work out more for the mental than the physical aspect," Hunnam added. "I can get slightly dark when I'm not keeping a routine. It's all about feeling healthy and energetic."

It turns out that Hunnam also likes to keep a strict routine when it comes to his career. He told Men's Health that wrapping the final season of "Sons of Anarchy" and shooting "Fifty Shades" was a little too much for him.

"I was going to finish playing a psychopath who'd just lost his wife, and five days later I'd be on set playing Christian Grey," he said, referring to his "Sons" character Jax Teller whose wife is brutally murdered. "I was like, 'This is going to be a f***king disaster."

"It was the opposite of how I've tried to ground my career, not stretch myself too thin, and always do my homework," he continued.

After a brief search, author E.L. James and Universal Pictures announced that the role of Christian would be portrayed by "Once Upon a Time" star Jamie Dornan. Hunnam, who said in the past he plans on still watching the movie in theaters, also discussed his exit during an interview with MovieFone.com

The actor said he dropped out after he suffered a "nervous breakdown." Hunnam explained that his schedule was over-packed and he did not have the time to work on playing the kinky billionaire who falls for Anastasia Steele (Dakota Johnson).

He also had signed on to star in Guillermo del Toro's "Crimson Peak."

"I was going to finish 'Sons' at like 11 p.m. Friday night, get on the plane Saturday morning to Vancouver for 'Fifty, missing the whole first week of rehearsal and start shooting Monday morning," he said. "And I was going to shoot that film, wrap that on a Wednesday and the following Monday I was going to start shooting 'Crimson Peak' in Toronto. I just had like... frankly, something of a nervous breakdown."