Simone Biles reveals devastating reason for Olympics withdrawal

Simone Biles has revealed she was battling mental demons when she abruptly withdrew from the women's gymnastics team final after just one vault on Tuesday night.

The American star's bid for a record six gold medals at the Tokyo Games ended in shock fashion when she dropped out of the women's team final and watched as the United States surrendered their title to Russia.

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The entire event was turned on its head in an instant when Biles, the world and Olympic all-around champion, completely mistimed her opening vault to earn a low score of 13.766.

She then withdrew, with USA Gymnastics citing a "medical issue".

But facing the media after the shock decision, Biles said she wasn't injured but fighting some mental demons.

Biles' future at the Tokyo Games is now in doubt, admitting she is unsure whether she will compete on Thursday in the women's all-around event.

"After the performance I did I just didn't want to go on," said Biles, fighting back tears as she met with the media.

"We are going to see about Thursday. I'm just trying to gear up for the next test."

USA Gymnastics said in a statement Biles had withdrawn because of a "medical issue", and would be assessed daily.

"Injury, no," she said. "Just a little injury to my pride.

“It’s just me in my head. I have to focus on my mental health and not jeopardise my health and wellbeing.

“We have to protect our body and our mind.

“It’s very unfortunate this has to happen at this stage ... it just sucks when you’re fighting with your own head.”

“Tonight they (her teammates) get a gold medal from me for fighting.”

Biles added: “Physically, I feel good, I’m in shape. Emotionally, that kind of varies on the time and moment.

“Coming here to the Olympics and being the head star isn’t an easy feat, so we’re just trying to take it one day at a time and we’ll see.”

World in shock over Simone Biles withdrawal

It was a stunning and disappointing start to the Olympics for the US women, who had expected to dominate the final as they had not been beaten in a major team competition since 2011.

Fans and commentators around the world were left in disbelief.

Former teammate Aly Raisman said she was "sick to my stomach" and in "complete devastation".

“I think that Simone is the biggest story going into the Olympics, so this is just - it’s really, really devastating,” Raisman told 'Today'.

“But I think it’s also just really important to think about how much pressure has been on her, and there’s only so much that someone can take.

"She’s human, and I think sometimes people forget that. And Simone, just like everyone else, is doing the best that she can."

Reporter Nancy Armour tweeted: “OMG. Simone bailed out of the Amanar, does a 1.5. Nearly lands it on her knees. And looks as if she’s about to cry as she comes off the podium, Cecile immediately goes and puts arm around her.”

American TV presenter Hoda Kotb said “the place was just stunned".

It was a setback the US never recovered from as Russia, competing as representatives of the Russian Olympic Committee (ROC) because the country was stripped of its flag and anthem for doping offences, claimed the team title for the first time since the Unified Team at the 1992 Barcelona Games.

The US, winners in 2012 and 2016, settled for silver and Britain claimed the bronze.

with AAP

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