Simone Biles will not defend her Olympic gold in Thursday's all-around final.

She needs to focus on her own mental well-being.

"After further medical research, Simone Biles has withdrawn from the individual all-around final in the Tokyo Olympics to focus instead on her mental well-being," the US Gymnastics Association wrote in a statement.

Yesterday, the American gymnastics star chose to withdraw from the team final.

The 24-year-old announced that she did it because of the high expectations she had.

"We wholeheartedly support Simone's decision and commend her courage to prioritize her well-being," the United States Gymnastics Association wrote on Twitter.

The American Confederation also points out that Biles shows great courage with her decision - and that this in turn explains why she is a role model for so many.

The text is updated.