Mark Wahlberg's body is already legendary for its buff biceps, sprawling pectorals and washboard abs, but to play a bodybuilder opposite pro wrestler Dwayne "The Rock" Johnson in Michael Bay's Pain and Gain, Wahlberg, 40, undoubtedly had to endure his fair share of pain to gain more muscle.

Even while on set in Miami on Tuesday, Wahlberg — decked out in a revealing, white tank top and striped gym shorts — could be seen flexing his bulging brawn, performing such stunts as hanging by the knees from a wall and doing crunches vertical to the ground, according to

A father of four, Wahlberg has said that his low-key lifestyle (WIFE) keeps him healthy and on a smart schedule; he doesn't go out partying like he used to. "You work a 12-hour day, then go to dinner, then go out for 4 hours? You're done. That's the stuff that kicks your ass," he told Men's Health in 2008. "I'm up at 6 in the morning. I put the eggs on, eat, hit the gym. I just get it all done."

But not all of Wahlberg's movie roles call for intense training. He will next appear opposite Mila Kunis in Ted, the feature film directing debut from Family Guy creator Seth MacFarlane. The R-rated comedy is about a grownup man (Wahlberg) whose childhood wish that his Teddy bear (voiced by MacFarlane) was real comes true — with hilarious results, of course.

Watch the trailer for Ted here (NSFW):

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