Channing Tatum was “flexing so hard” in a nude Instagram selfie that he gave himself cramp.

The Magic Mike star shared the racy snap on his Instagram Stories, as he revealed he was gearing up for filming a scene on his upcoming action romantic comedy, The Lost City of D.

In the black-and-white snap taken in his trailer, Channing used an emoji of a monkey with its hands over its mouth to preserve his modesty.

“You know when you in the make-up trailer a**hole naked holding a towel over your junk you about to do some s**t on set that you gonna have to prepare ya mama for before she see the movie (sic),” he captioned the image.

But he confessed he was straining to make his muscles look as ripped as possible and managed to injure himself.

“And yes I’m flexing so hard i got a cramp (sic),” he quipped.

Channing recently detailed the numerous workouts he does to get in shape for movie roles, and said that open water swimming has helped him this time around.

“There are moments in both that i am always like i think I might die haha. Yup pretty sure i can’t go on let go would be better than this. Haha… and I’m not even i professional athlete. I can’t imagine the depths in which they push themselves. Unreal,” he shared alongside a video of him walking out of the ocean.

The Lost City of D stars Sandra Bullock as a romance novelist who becomes part of an attempted kidnapping during a book tour with her novel’s cover model, played by Channing, and is set to be released next year.

– Cover Media