Chris Stokes, GORUCK Light qualified cadre, standing,

Chris Stokes, GORUCK Light qualified cadre, standing, instructs 31 participants on a team pushup challenge Sept. 25, 2015, on Dover Air Force Base, Del. During the five-hour-long GORUCK Light team cohesion challenge, Stokes, a former U.S. Marine Corps reconnaissance member, presented Team Dover members with numerous physical challenges along a 7.8-mile course as they learned to overcome adversity by working as a team. (U.S. Air Force photo/Roland Balik)