Simone Biles entered the 2021 Tokyo Olympics with sky-high expectations after dominating the competition at the 2016 Olympics.
Biles won the all-around gold at the Rio Olympics and also led Team USA to gold in the team competition. She had only improved since her Olympic debut — which came at 19 — and many believed she would challenge or break Shannon Miller's record for medals by an American gymnast.
Biles was able to tie Miller's record, but things didn't exactly go to plan. She struggled in the early stages of her time in Tokyo, and those issues came to a head during the team competition.
Biles fell after attempting a vault early in the competition and exited the floor. She later withdrew from that contest as many feared she had suffered a major injury.
It turned out nothing was physically wrong with Biles — she simply was dealing with a mental issue known as the "twisties," which forced her to withdraw from several event finals at the 2021 Olympics.
Here's what to know about Biles' ordeal in Tokyo and her return to the Paris Olympics in 2024.
MORE: Meet the full Team USA gymnastics roster for Paris 2024, from Simone Biles to Hezly Rivera
What are the 'twisties'?
The "twisties" are a nickname given to a mental block that gymnasts suffer that causes them to lose track of where they are while in the air.
The twisties can take many different forms. Sometimes, gymnasts add an extra, unplanned twist to their rotation that throws them off. Other times, they will stop midway through a move to better position themselves to land.
Biles described her case of the twisties by captioning an Instagram story of herself, "My mind and body are simply not in sync."
Accompanying the explanation was a video of Biles landing on her back while trying to land her uneven bars dismount.
On her IG stories, Simone Biles responds to people who think she “quit” on her team by explaining the “the twisties” she’s been experiencing and what it feels like “not having your mind and body in sync” …. pic.twitter.com/79hN973rkd
— Kimberley A. Martin (@ByKimberleyA) July 30, 2021
That lack of synchronization — and her subsequent inability to comfortably land her routines — caused Biles to back out of several events at the 2021 Olympics.
MORE: Where Simone Biles ranks among the greatest Summer Olympians ever
Why did Simone Biles withdraw from 2021 Olympics?
Biles withdrew from almost all of her events at the 2021 Olympics because of her case of the twisties. She participated in qualifying early in the Summer Games but bowed out during the team competition after missing a twist on her first vault attempt and falling on her landing.
Many believed Biles was injured after her landing, but she later revealed her issue was mental.
"Once I came out here, I was like, no, the mental is not there," Biles said at the time of her withdrawal.
While some called for Biles to push through that mental block, she noted that attempting to fix her issues on a competition surface would have been too risky.
"At the end of the day it’s like, we want to walk out of here, not be dragged out here on a stretcher," she told reporters. "I just don’t trust myself as much as I used to."
That worry influenced Biles' decision to withdraw from the team competition and individual finals on the vault, floor, and uneven bars. Many wondered if her Olympic career had come to an end, but she did return to action on one apparatus.
MORE: How to watch 'Simone Biles Rising' documentary about Olympic comeback
Simone Biles medals on balance beam after twisties
Biles announced she would return for the final individual event at the 2021 Olympics: the balance beam.
After qualifying in seventh place, Biles put together a strong score of 14.000. That was enough to earn a bronze medal, as she was 0.134 points ahead of Canada's Ellie Black on the scorecard while being within 0.633 points of gold-medal winner Guan Chenchen.
Biles' beam routine was slightly easier than her normal routine, as it had a difficulty score (D score) of just 6.100. That capped her ceiling a bit, but as she acknowledged after the event, she was simply happy to perform in the event.
"To do beam, which I didn't think I was going to be, just meant the world to be back out there," Biles said. "And I wasn't expecting to walk away with the medal. I was just going out there doing this for me."
She also addressed the mental strife that came with her decision to drop out of event finals on the other apparatuses.
"It wasn't easy pulling out of all those competitions," Biles said. "People just thought it was easy, but I physically and mentally was not in the right head space and I didn't want to jeopardize my health and my safety because, at the end of the day, it's not worth it. My mental and physical health is above all medals that I could ever win."
Even so, Biles' bronze medal win gave her seven total from her Olympic career and allowed her to match Miller's record as the most decorated female gymnast in Team USA's history.
That, along with some other comments from Biles, led many to speculate her Olympic career was over.
MORE: Breaking down Simone Biles' Olympic timeline, medals & more
Simone Biles retirement rumors
Many believed Biles — who was 24 at the time of the Tokyo Olympics — would call it a career after the event. She poured some fuel on that fire when she revealed gymnastics was causing her stress as she dealt with the twisties.
"And I don’t know if it’s age — I’m a little bit more nervous when I do gymnastics," Biles said. "I feel like I’m also not having as much fun, and I know that."
Biles was also asked point-blank about whether she would try to make the Team USA roster for the 2024 Olympics in Paris. She was non-committal about her plans for the event.
"Paris is definitely not in my mind frame because I think there are so many things that I have to work on for myself first," she said.
Given Biles' comments and the fact that she'd be 27 at the Paris Olympics, many believed she would pass the torch.
Instead, she decided to take another shot at Olympic gold.
MORE: Full TV schedule for the 2024 Olympics
Simone Biles' 2024 Olympics comeback
Biles took a break from competition after the 2021 Olympics. She didn't compete in any senior gymnastics events in 2022 but returned to action at the 2023 U.S. Classic.
Getting there took a lot of work, as she told Today. That included going to therapy, re-discovering joy in the sport, and setting a goal on her own terms.
"I would say the only thing I have to prove is to myself that I can get out there and do it again," she said.
Biles also had to let go of the nerves she still felt from her experience in Tokyo.
"It took a while because I was watching gymnastics on TV, but then, every time somebody twisted (in midair), I was like, 'Oh, my gosh,'" Biles said. "So, I feel like, one day I just woke up and I was like, 'OK, let's try this again.'"
From there, Biles had to convince her coaches to let her aim for another Olympic berth. They were skeptical, as Biles would be 27 by the time the 2024 Summer Games rolled around; Team USA hadn't taken a female gymnast of that age to the Olympics since 1952.
"I was like, 'OK, I want to go to the Olympics again.' And they were like, 'No,'" Biles said. "And I was like, 'That’s strange. That’s so weird.'
"And then they were kind of like, 'Get back in the gym. Get your skills back. Let’s see if you actually want to do this so that we’re all collectively deciding that we’re really going to go for it.'"
Biles did just that and decided she wanted to give Paris a go. She returned to senior-level competition at the 2023 U.S. Classic, which she won by five points over Leanne Wong. From there, Biles continued to compete, earning gold in the 2023 World Championships and showcasing she was still the best gymnast in the world — and possibly of all time.
Biles then did everything she had to do to automatically qualify for the 2024 Olympics. She starred at the U.S. Championships and demonstrated her well-rounded game at the Team USA trials.
Now, she is set to return to the world's biggest stage. Her goal now is to bring a gold medal home with her, something she wasn't able to do in Tokyo.
"This is definitely our redemption tour," Biles said at the U.S. Olympic trials, per Olympics.com. "I feel like we all have more to give...I feel like we have a lot of weight on our shoulders to go out there and prove that we're better athletes, we're more mature, we're smarter, we're more consistent."
