LANGLEY AIR FORCE BASE, Va. -- Airman 1st Class Brendan Davis, 1st Aerospace Medicine Squadron, laces his shoes as Airman 1st Class Catherine Leahy, 1st Force Support Squadron, examines other participants before a duathlon Aug. 15. A duathlon is an eight mile exercise designed to challenge each participant's physical endurance with cycling and running. The 1st FSS organizes an event monthly to continue encouraging physical fitness as the Air Force exercises the fit to fight mentality. (U.S. Air Force photo/Senior Airman Vernon Young)