U.S. Army Spc. Ashley O’Hearn (left), a brigade aviation operations specialist, from Pipestone, Minn., shouts words of encouragement to U.S. Army Staff Sgt. Brenda Caldwell, a supply sergeant, from Omaha, Neb., both with the Iowa National Guard, 2nd Brigade Combat Team, 34th Infantry Division, Task Force Red Bulls, while she completes a round of push-ups during a Memorial Day "Murph" CrossFit workout at the clamshell gym on Bagram Air Field, Parwan province, Afghanistan, May 29.