U.S. Air Force Airman 1st Class Stefan Kunz, 355th Maintenance Operations Squadron, executes box jumps as part of his work out at the Haeffner gym at Davis-Monthan Air Force Base, Ariz., Sept. 23, 2013. Snider is preparing for the Attack Fitness Competition later this week. (U.S. Air Force photo by Senior Airman Camilla Elizeu/Released)