TOKYO - Simone Biles was left weighing her Olympic future on Tuesday (July 27) after dropping out of the women's gymnastics team final at the Tokyo Summer Games after one disappointing vault saying she had to focus on her mental health.

For so long Biles had appeared invincible, racking up 30 world and Olympic medals in a spectacular career that was expected to come to a closely-watched climax in Tokyo as she launched a bid for six gold medals that would make her the greatest female Olympic champion of all time.

But just as her quest got underway on Tuesday it all unravelled, the 24-year-old American later conceding that the pressure of living up to expectations had left her no other choice but to stop after one vault.

The retirement from the team competition has left Biles' future participation at the Tokyo Games in limbo.

She had been expected to feature in all six events at the Games that included a defence of her all-around crown on Thursday followed by four apparatus finals next week.

"I do not trust myself anymore," said Biles, fighting back tears as she met with the world's media. "I have to focus on my mental health.

"There is more to life than just gymnastics.

"It is very unfortunate that it has to happen at this stage because I definitely wanted these Olympics to go a little bit better.

"We have to protect our mind and our body rather than just go out there and do what the world wants us to do."

First step

What many wanted to see was Biles take the first step towards six gold medals that would make her the greatest female Olympian of all time.

But what they saw instead was a stunning breakdown as Biles ended her evening after one vault, her score of 13.766 the lowest on the US team that without their leader went on to surrender the team title to Russia, settling for silver.

Stunned and close to tears, Biles, gold medal winner on the vault at the Rio Olympics, sat dejected in a chair as coaches and team mates surrounded her before moving onto the uneven bars, the US sitting second, 1.067 behind the Russians.

Biles, however, appeared to be more than simply disappointed, leaving the arena with the trainer as her team mates warmed up.

By now coaches and officials sprinkled throughout the Ariake Gymnastics Centre had begun to chatter as Biles reappeared minutes later after slipping into her warm-up gear.

"After the performance I did I just didn't want to go on," said Biles, who will pick up her sixth Olympic medal for being part of the US squad that earned silver. "We are going to see about Thursday.

"It’s going to be a quick turnaround.

"It is what it is, whatever happens, happens and it’s going to be completely fine."

Warning signs

There were warning signs that Biles had been struggling to live up to her high standards.

At the US Olympic Trials in June she was left in tears when she was unable to come to grips with the disappointment of her performance.

The pressure of chasing medals continued to build in Tokyo, Biles posting on social media after Sunday's uninspired qualification effort that she felt she was carrying the weight of the world.

"It wasn’t an easy day or my best but I got through it," Biles wrote on Instagram. "I truly do feel like I have the weight of the world on my shoulders at times.

"I know I brush it off and make it seem like pressure doesn’t affect me but damn sometimes it’s hard hahaha!

"The Olympics is no joke!"

Robert Andrews, a mental training expert who worked with Biles for about four years, told Reuters he suspected stress played a large factor in Tuesday's outcome.

"Gymnastics probably more than any other sport... requires laser, pinpoint focus," said Andrews. "Being a global presence, the greatest of all time, all that starts creating interference."

He added: "If she’s this stressed out to where she has a mental block, I would approach it with caution.”

There was an instant outpouring of support for Biles on social media.

"Gratitude and support are what @Simone_Biles deserves," White House Press Secretary Jen Psaki said on Twitter. "Still the GOAT and we are all just lucky to be able to see her in action."

United States Olympic and Paralympic Committee (USOPC) CEO Sarah Hirshland applauded Biles for her bravery.

"Simone, you’ve made us so proud," said Hirshland on Twitter. "Proud of who you are as a person, team mate and athlete.

"We applaud your decision to prioritize your mental wellness over all else, and offer you the full support and resources of our Team USA community as you navigate the journey ahead."