U.S. Air Force Airman 1st Class Jacob D’Agostino, 633rd Security Forces Squadron response force leader, performs lunges during a physical training test as part of Air Combat Command’s Defender Challenge team selection at Joint Base Langley-Eustis, Virginia, Aug. 24, 2018. Nine Airmen competed over a five-day-period in various events, including a ruck march, land navigation, and M4 carbine and M9 pistol tactics and proficiencies. (U.S. Air Force photo by Staff Sgt. Areca T. Bell)