Mark Zuckerberg on Instagram: "I try to do the Murph challenge with the girls every Memorial Day as a tradition to honor those who defended us. One of Lt Murphy's favorite workouts was running a mile, then doing 100 pull ups, 200 push ups, 300 squats, and then running another mile -- all while wearing a 20lb weighted pack. This year I got it done in 39:58. The girls did a quarter-Murph (unweighted) in 15 mins!" | Zootzle