Participants in the Maltz Challenge perform the knees to elbows exercise at Kirtland Air Force Base, N.M., March 15, 2019. The Maltz Challenge is a timed, team competition that consists of a 400-meter run, 50 pull-ups, 100 yard fireman’s carry, 50 dips, 100 push-ups, 50 knees-to-elbows, 100 sit-ups and another 400-meter run. (U.S. Air Force photo by Airman 1st Class Austin J. Prisbrey)