Allyson Felix, of United States smiles after taking the bronze, in the final of women's 400-meters at the 2020 Summer Olympics, Friday, Aug. 6, 2021, in Tokyo, Japan. (AP Photo/Francisco Seco)

Shaunae Miller-Uibo, of Bahamas crosses the line to win the gold medal ahead of Allyson Felix, of United States, bronze, in the final of women's 400-meters at the 2020 Summer Olympics, Friday, Aug. 6, 2021, in Tokyo, Japan. (AP Photo/Francisco Seco)

Bronze medalist Allyson Felix, of the United States, poses during the medal ceremony for the women's 400-meter run at the 2020 Summer Olympics, Friday, Aug. 6, 2021, in Tokyo. (AP Photo/Martin Meissner)

Shaunae Miller-Uibo, of Bahamas crosses the line to win the gold medal ahead of Allyson Felix, of United States, bronze, in the final of women's 400-meters at the 2020 Summer Olympics, Friday, Aug. 6, 2021, in Tokyo, Japan. (AP Photo/Charlie Riedel)

Allyson Felix, of United States smiles after taking the bronze, in the final of women's 400-meters at the 2020 Summer Olympics, Friday, Aug. 6, 2021, in Tokyo, Japan. (AP Photo/Francisco Seco)

Bronze medalist Allyson Felix, of the United States, poses during the medal ceremony for the women's 400-meter run at the 2020 Summer Olympics, Friday, Aug. 6, 2021, in Tokyo. (AP Photo/Martin Meissner)