Charlie Hunnam, the British actor who rose to fame as Jax Teller on the hit FX series "Sons of Anarchy," has just landed one of the most coveted roles in Hollywood. As announced by "Fifty Shades of Grey" author E.L. James this morning, the 33-year-old actor will appear in the upcoming film version of the hit novel as the billionaire industralist Christian Grey.  "21 Jump Street" actress Dakota Johnson will play the role of Anastasia Steele.

For those familiar with Hunnam's work on "Sons of Anarchy," it's easy to see why producers selected him for the role of Grey. Unlike other actors that transform their bodies for specific roles, Hunnam consistently hits the gym - telling Men's Fitness that for him, staying in shape has benefits way beyond the physical. 

“The benefit of working out is 90 percent mental and 10 percent physical,” he says. “I feel better — like that I have more energy. But the mental side is an extraordinary benefit. I’m happier, more confident, and more positive when I work out. And I feel like I’m a better actor because of the clarity it gives me.”

While it's unclear whether he'll be assigned a personal trainer for "Fifty Shades," it's evident Hunnam doesn't really need one. Pull-ups, dips, swimming, bodyweight moves, and other intense routines are all squeezed daily into what can sometimes be 15-hour workdays. 

"Being an actor is fantastic because you get to live your dreams and all of that, but I always think it's slightly irritating when you hear from the outside world and people are like, 'Yeah, well if I was an actor and all I had to do was look good, I could be that ripped too.' Well I've got news for you, man! I work 15 hours a day and still go to the gym," he tells GQ. "Most people work eight hours a day and say 'I haven't got time to work out.' Bulls***! If you want to be super-fit and look ripped then you find the time no matter what."

More recently, Hunnam started including Bartendaz workouts into his routine; which mixes up acrobatic moves with martial arts and other physical movements. Up until his casting in the recent scifi film "Pacific Rim," the actor also had plans to travel to China to study Wing Chun kung fu in the famed Shaolin Temple. 

"I still actually intend to do that, although I'm not sure if I'm going to go to China; I might actually go to Thailand and do a month-long intensive Muay Thai academy," he says.

Check out Hunnam performing some of his workouts for Men's Fitness below. "Fifty Shades of Grey' will be released by Focus Features on August 1, 2014. 

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

Charlie Hunnam's 'Fifty Shades' workout may include martial arts
'Pacific Rim' actor is already in phenomenal shape to tackle the coveted role of Christian Grey in the upcoming erotic drama.