Since then, she has been unstoppable as she proved, in routine after routine, that she has worked past the mental block that derailed her three years ago in Tokyo -and that she is still the world’s best gymnast.
But during her first competitive performance in Paris, in the qualifying round, Biles’ body threatened to thwart her again.
This time, it was a physical ailment, rather than the dangerous mind-body disconnect that rattled Biles amid the pressure of the previous Olympics. But it still seemed like deja vu, with Biles alongside the team doctor as questions lingered about whether the sport’s biggest star would be able to continue.
During warm-ups before floor, Biles felt minor pain in her left calf, a re-emergence of an issue from a couple of weeks ago, her coach, Cecile Landi, said afterwards.
Wrapping her lower leg with tape was enough to help Biles push through. But while she warmed up her vaults soon after, she at one point crawled alongside the runway and hopped on one foot.
She then practised her difficult Yurchenko double pike and landed short, an unusual error for Biles - and a sometimes painful mistake.
The uncertainty lingered briefly, palpable in an arena packed with thousands of fans and a few A-list admirers, including Tom Cruise, Ariana Grande and Jessica Chastain. But Landi said finishing the competition was never in doubt for Biles, who did not talk to reporters afterwards.
When it counted, Biles sprinted down the runway and soared off the vault, flipping twice in a pike position. It’s the hardest vault in women’s gymnastics, but Biles makes it look easy - even amid an injury scare.
As she headed to bars, “she started to feel better”, Landi said. Biles hit another routine to post a 59.566 all-around total, her second-best mark since Tokyo.
Biles’ performance was “pretty amazing”, Landi said, adding that she does not have any concerns about whether Biles will be able to continue competing.
Despite the injury and some missteps, Biles managed to lead the United States women through the meet as a steadying force.
She stepped out of bounds on the floor, just after the calf pain flared up, and she ended up having too much power on the vault, despite not rotating enough in warm-ups, so she took two big steps backward.
The other Americans had more nervy moments. All the gymnasts who joined Biles in the beam line-up wobbled on multiple skills, particularly 16-year-old Hezly Rivera in her Olympic debut.
And Jade Carey, who said on social media that she hasn’t been feeling well, bailed out of her final tumbling pass on floor, leading to a low score that will keep her from defending her Olympic gold medal on the apparatus.
Even with the mishaps, the US team’s mark of 172.296 was plenty to lead the field with three sessions to go. The Americans will be the heavy favourites to win the team gold, particularly given the absence of Russia, a longtime power in gymnastics, whose athletes are banned from team competition here.
The athletes from the Russian Olympic Committee won the gold ahead of the Americans in Tokyo after Biles’ withdrawal led to a chaotic team final.
In the qualifying round, Sunisa Lee, the reigning Olympic all-around champion, edged Jordan Chiles by less than one-tenth to earn a spot in the all-around final. Though Chiles’ 56.065 is the third-best mark so far, countries cannot have more than two gymnasts in each final, and Lee (56.132) narrowly prevailed.
Biles, expected to win the all-around gold, will be the headliner each time she competes. But Landi has said that having three other returning Olympians on this team eases the pressure on Biles.
And together, the gymnasts have described this Olympics as their “redemption tour”. All four returners - Biles, Lee, Carey, and Chiles - have something they want to achieve that they missed out on three years ago, nobody more so than Biles.
The injury, no matter how minor, only adds to the curiosity around how Biles will manage this massive spotlight.
In her first test, though, Biles excelled.
She tallied the best score of the day so far on vault and floor, as well as the second-best mark on beam.
After she finished her final routine, she waved to the crowd and then danced with Chiles to celebrate.
The calf issue added uncertainty to Biles’ Olympic quest, which could end with up to five gold medals, but her dominant performance amid the trouble resembled all of her other outings since Tokyo.
One after another, Biles’ brilliant routines washed away the concern.
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