Ian Somerhalder’s been blessed with naturally gorgeous looks, but no one (not even Ian) is born with washboard-like abs.

In order to stay in tip-top shape for those droolworthy shirtless scenes, the Vampire Diaries star prescribes to the Prison Workout exercise routine. The sweat-inducing regimen consists of burpees, pull-ups, push-ups, body planks, and squat jumps. (Doesn’t sound like something we’ll be trying soon, but it certainly works for Ian!) The plan was devised to be done anywhere, even in the smallest of spaces — think on-set trailers, hotel rooms, and yes, even prison cells!

Of course, Ian knows he looks best when he’s trim and toned, not blown up like a bodybuilder. To counter the muscle-building effect of the workout, Ian adds cardio to blast fat and keep him looking lean. In fact, the blue-eyed hottie was recently spotted out for a run on the streets on NYC (photo at left).

On top of frequent sweat sessions, Ian credits lots of sleep and water for helping him stay hot. Though the animal lover’s not a vegetarian, he does stay mindful of where he gets his meat: “I do mostly ONLY eat from farms that treat animals with dignity & that are harvested humanely,” Ian tweeted. “Cruelty SUCKS.”

It’s all working for you, Ian!