U.S. Marine Cpl. William Bock, 22, of Philadelphia, worked out Tuesday under the light of his head lamp at Combat Outpost Shir Ghazay in Helmand Province, Afghanistan. (David Goldman/Associated Press) High-res

U.S. Marine Cpl. William Bock, 22, of Philadelphia, worked out Tuesday under the light of his head lamp at Combat Outpost Shir Ghazay in Helmand Province, Afghanistan. (David Goldman/Associated Press)