Olympic sprinter who won gold medals in the 4×400 m relay event at the 2004 and 2012 Olympic Games. She was also a three-time World Champion in the same event.
She was a champion collegiate athlete at the University of Tennessee.
She created the charity Test Me I'm Clean, which seeks to prevent the use of performance-enhancing drugs among athletes.
She has siblings named Yohan and Ian.
She won an Olympic team gold medal alongside Crystal Cox, who has since admitted to doping for the contest.