Combat control trainees from the 334th Training Squadron run back on shore after doing 100 jumping jacks in the Gulf of Mexico during a physical training session April 12, 2013, on Biloxi beach. Combat controllers are ground troops who are embedded with Special Forces teams and provide close-air support for special forces units. While at Keesler, trainees learn how to run, swim, carry a rucksack and conduct air traffic control. These airmen are prepared physically and mentally for the demands of the combat controller pipeline while earning air traffic control certification in just 15 weeks. (U.S. Air Force photo by Kemberly Groue/Released)