Mark Wahlberg: Underwear For 'Pain & Gain'!

Mark Whalberg strips down to his underwear on the set of Pain and Gain on Tuesday (April 17) in Miami, Fla.

The 40-year-old buff actor showed off his toned physique while filming a scene on a cellphone in a golf course.

PHOTOS: Check out the latest pics of Mark Wahlberg

The week before, Mark was spotted walking around the set with his co-star ‘The Rock’ Dwayne Johnson.

The new Michael Bay directed film, follows the story of a pair of bodybuilders that get mixed up in an extortion ring and a kidnapping scheme that goes terribly wrong.