A U.S. Soldier low crawls through mud under barbed-wire during the Mud Run at Forward Operating Base Salerno in Khost province, Afghanistan, March 24, 2013. More than 50 Soldiers assigned to various units from the forward operating base participated in the course. The two-mile course featured 15 different obstacles that challenged the Soldiers physically and mentally, while adding the elements of water and mud to help make the course even more difficult. (U.S. Army photo by Sgt. 1st Class Abram Pinnington/Released)