When you hang out with your friends, you might get brunch or binge on your favourite TV shows, but when Chris Pratt and John Krasinski get together, they prefer to sweat. A lot. The actors, who both bulked up for their respective roles as soldiers in Zero Dark Thirty and 13 Hours, honoured America's armed forces on Memorial Day by doing a Murph workout. The intense challenge is an ode to Navy Lieutenant Michael Murphy, 29, who was killed in Afghanistan in 2005 and loved doing this workout set in particular (a one-mile run, 100 pull-ups, 200 push-ups, 300 squats, and another one-mile run). "Michael Murphy was a Navy SEAL, one of the many in uniform who gave his life for our country," Chris says in an Instagram video, which shows both him and John dripping sweat. "It's days like today when we just commemorate all those fallen heroes, and we say thanks for all you do to make our dreams come true."