Career Highlights: A staff sergeant in the U.S. Army as a part of the World Class Athletic Program unit, Nunn has one of the more interesting - and wide-ranging - stories of any American Olympian. He got a full scholarship to the University of Wisconsin-Parkside for race walking in the mid-1990s, then after one year of college served a two-year Mormon mission in Las Vegas. He qualified for the 2004 Olympics in the 20K race walk by finishing second at the U.S. trials, but ended up a disappointing 26th in Athens. Nunn's next four years didn't go well, as he went through a divorce and missed out on qualifying for the Beijing Games. But Nunn has continued to compete, and became the lone American race walker to qualify for London after finishing first in the 2012 U.S. trials in the 50K with a time of 4:04:41. He doesn't expect London to be his last gasp at Olympic glory, either. Nunn, who has the five Olympic rings tattooed on his back, plans to keep racing through the 2016 Games before going to dental school.