Breathing required: Faster, Stronger, Cheaper
U.S. Air Force Maj. Christy Zahn, 52nd Operations Support Squadron aerospace and operational physiology training team flight commander from Los Alamos, N.M., briefs about the physiological effects of flying to Airmen prior to a familiarization flight July 28, 2014, at Spangdahlem Air Base, Germany. Members of the aerospace physiology training team operate a reduced oxygen breathing device, which is used to teach pilots how combat hypoxia. (U.S. Air Force photo by Senior Airman Rusty Frank/Released)