Jim's Jacked! John Krasinski Shows Off Totally Ripped Shirtless Body in '13 Hours'

John Krasinksi‘s days being the adorable jokester at Dunder Mifflin are long gone.

The actor recently bulked up for his turn as a Navy SEAL in his new movie 13 Hours: The Secret Soldiers of Benghazi, and the results are, well, breathtaking.

In a shot from the action film, Krasinski wore only a pair of low-slung jeans, making his chiseled abs the main event.

Krasinski’s new figure is the result of some hard work on a time crunch – the star told Men’s Health he got shirtless-ready in only 16 weeks.

Trainer Jason Walsh helped Krasinski, 36, tackle his new lifestyle change and worked with him on both burning fat and adding muscle – two times a day, five times a week. The plan worked (obviously) and the actor got his body fat percentage down from 26 percent to 5 percent.

“I gotta be honest: It was brutal at times,” the star told the magazine of his fitness regimen. “We did tons of metabolic work, dragging sleds and all this stuff I ve seen NFL players do.”

John Krasinski in a Silver Fringe Dress Is Everything

Not everyone is loving Krasinski’s hot new look though. Namely, the actor’s wife Emily Blunt.

“She hates it,” Krasinski said during an appearance on The Late Show. “She would way prefer to have doughy guy back.”