Karsten Warholm, of Norway, celebrates after winning the gold medal in the men's 400-meter hurdles at the 2020 Summer Olympics, Tuesday, Aug. 3, 2021, in Tokyo.(AP Photo/David J. Phillip)

Karsten Warholm, of Norway celebrates next to the scoreboard showing his world record as he wins the gold medal in the final of the men's 400-meter hurdles at the 2020 Summer Olympics, Tuesday, Aug. 3, 2021, in Tokyo, Japan. (AP Photo/Martin Meissner)

Karsten Warholm, of Norway celebrates as he wins the gold medal ahead of Rai Benjamin, of United States in the final of the men's 400-meter hurdles at the 2020 Summer Olympics, Tuesday, Aug. 3, 2021, in Tokyo, Japan. (AP Photo/Charlie Riedel)

Karsten Warholm, of Norway celebrates as he wins the gold medal in the final of the men's 400-meter hurdles at the 2020 Summer Olympics, Tuesday, Aug. 3, 2021, in Tokyo, Japan. At right is Alison Dos Santos, of Brazil, who took the bronze. (AP Photo/Martin Meissner)

Karsten Warholm, of Norway celebrates as he wins the gold medal in the final of the men's 400-meter hurdles at the 2020 Summer Olympics, Tuesday, Aug. 3, 2021, in Tokyo, Japan. At right is Alison Dos Santos, of Brazil, who took the bronze. (AP Photo/Martin Meissner)

Karsten Warholm, of Norway celebrates as he wins the gold medal in the final of the men's 400-meter hurdles at the 2020 Summer Olympics, Tuesday, Aug. 3, 2021, in Tokyo, Japan. (AP Photo/Charlie Riedel)