Henry Cavill is currently in Detroit filming scenes for the upcoming sequel to the superhero flick "Man of Steel" (given the unofficial title "Batman Vs. Superman"). While the actor has been busy saving the world, he took some time out to volunteer at a Crossfit competition at Motorcity Crossfit, Comicbookmovie.com reports.

Fans eagerly approached Cavill to ask for pictures. It's not clear if Crossfit is part of Cavill's grueling training to get in shape to play Superman but his fitness regimen has been documented before and from the sound of it Cavill put in a lot of work to get in shape for the film.  

Recently, Robert "Maximus" MacDonald, the General Manager and Training Director at Gym Jones in Salt Lake City, Utah told Moviehole.com that Cavill stopped by the gym in December to train with Mark Twight and Michael Blevins.

"[Henry Cavill] was in Salt Lake City over Christmas, but a pleasure to work with him because he just works hard. No excuses. He shows up, he does what he has to do. He challenges himself and he goes home," MacDonald said. "There was a couple of times in Salt Lake City where he was my workout partner and I gotta tell you, a lot of people disappoint me when they train with me, he didn't disappoint me in the least."

MacDonald said he thinks people would be surprised to know just how physically strong Cavill is.

"He didn't go home to England and party [for Christmas]," he continued. "He didn't do all the things that I suppose a normal person would have done. He said 'I'm not gonna take a Christmas break off, I wanna be as good as I can be,' and he came to see us."

The actor is no stranger to intense and grueling workouts and worked with Twight to prepare for the first "Man of Steel" movie. In a 2011 interview, Twight told Muscle & Fitness magazine that he worked with Cavill for an entire year to help him bulk up for the superhero role.

He explained that the first five months were prep work and the last seven was devoted to maintaining as Cavill shot Zack Snyder's film. Twight has also been credited with bulking up Gerard Butler for his role in "300" and Russell Crowe, who played Superman's father.

So what exactly did Cavill do to get those chiseled abs? Twight said the actor was expected to get nine to 10 hours of sleep a day, eat 5,000 calories a day and train for two hours five or six days a week.

"What we are trying to do is use physical means to basically prepare a person or challenge them in a psycho physical way so they can actually play a role in this context," he told ABC News. "So you need a guy to look like Superman? It will be better if he feels super in order to transmit that message."

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