 Complete the following phrase:  Clayton Parros born December 11, 1990 is an American male track and field sprinter who specializes in the 400-meter dash. He was a runner in the gold medal-winning American 4 × 400 metres relay teams at the 2009 Pan American Junior Athletics Championships and the 2015 NACAC Championships in Athletics, setting a championship record of 3:00.07 minutes at the latter meet. He also ran as the alternate heats runner for the American teams that won gold medals at the 