U.S. Army World Class Athlete Program race walker Staff Sgt. John Nunn (No. 2 in center) leads Ben Shorey (No. 1), Tim Seaman (No. 5) and Erich Cordero (No. 7) in the 2012 U.S. Olympic Trials for Men's 50K Race Walk on Jan. 22, 2012, in Santee, Calif. Nunn won the race with a time of 4 hours, 4 minutes, 41 seconds, a pace of 7:53 per mile.