Matthew Corcoran, left, 56th Force Support Squadron CrossFit group instructor, punches a combat pad held by U.S. Marine Corp. Lance Cpl. Jay Clayton, Bulk Fuel Co. C, 6th Engineer Support Battalion, during their military combative training course at Luke Air Force Base, Ariz., April 7. Participants of the course ran around Luke stopping periodically to practice the techniques they learned. (U.S. Air Force photo/Airman 1st Class Ronifel Yasay)