Jeremy Wariner, the 2004 Olympic 400m champion, has retired at age 33, according to Sports Illustrated.
The 2016 Olympic Trials were then considered the last gasp for Wariner, who won gold after his sophomore year at Baylor but struggled with injuries the last several years.
He cramped up in the Trials semifinals to miss the Rio team. Wariner raced twice in small meets this year before hanging it up.
Wariner goes out as the fourth-fastest 400m man all time with a personal best of 43.45 seconds. He last broke 45 in April 2012.