Simone Biles is not the first athlete to acknowledge how mounting pressure to perform and achieve has affected her mental health. But by stepping away from her events on the world’s biggest stage, Biles has forced the spotlight to shine on an issue that is long known to have affected elite athletes but has often been kept hidden in the shadows.

In June, Japanese tennis star Naomi Osaka stepped away from the French Open, one of her sport’s major events, to focus on her mental health after she was fined for not participating in press conferences. Now it’s Biles, who withdrew from the Olympic gymnastics team event and announced she will not defend her individual All-Around medal. Many other athletes are falling in line behind them in support and opening up about their own mental health issues.

"Other athletes that might have struggled with similar issues now feel like it's OK for them to talk about it,” Ben Miller, a psychologist and president of California-based Well Being Trust told Reuters. “There's something very powerful in that moment,"

U.S. Olympic gymnast Sam Mikulak on Wednesday praised Biles for prioritizing her mental health and said he was keen to help other athletes cope with the pressures of performing on the world's biggest stage. Mikulak, 28, has publicly acknowledged his own mental health struggles.

"Everyone wants athletes to be indestructible and perfect all the time," said Mikulak, who finished 12th in the all-around final. "Sometimes it's too much. And when that is the case, you have to do what is best for you."

Biles has been flooded with messages of support from fellow athletes after she pulled out of the events at the Tokyo Games. She drew backing from teammates, fellow Olympians and retired athletes, in a clear sign of how public discussion of issues such as stress and depression have become accepted on social media and more frequent in recent years, particularly since the pandemic.

"It broke my heart," U.S. swimmer Michael Phelps told broadcaster NBC. "But also, if you look at it, mental health over the last 18 months, is something that people are talking about."

Phelps, the greatest swimmer in history and the winner of 23 Olympic gold medals, has publicly discussed his own battle with depression, including contemplating suicide.

U.S. swimmer Erica Sullivan, who won the silver medal for the 1500m freestyle, also opened up about her own struggles in a news conference.

"I'm not facing a fraction of the pressure that Simone is," she said. “But there was a time in 2018 when I started getting psychological help for my issues, and there was a time when it was so bad that my coach told me I can't keep racing like this and I will not be racing until I get better.”

Isolation and the absence of family and friends have taken a toll on athletes' mental health at the Tokyo Olympics, with some struggling to cope with the challenges posed by the pandemic while carrying their country's hopes on the global sports stage.

Athletes have seen their pre-Olympic training disrupted by lockdowns and restricted access to athletic facilities, and the postponement of the Games fueled concern about qualification schedules and the ability to travel internationally without contracting the virus.

Their families and friends can't cheer for them in the stands in Tokyo and their movements are heavily restricted.

Even prior to arriving in Tokyo, athletes were facing new and unfamiliar pressures linked to the pandemic. They had to find ways to train during lockdowns and qualify for the world's biggest sporting event without compromising their health or that of their families and communities.

"It has been a difficult road since 2019," said gymnast Angelina Melnikova of the Russian Olympic Committee, who beat the United States to win gold in the women's team event.

After her team withdrawal on Monday, Biles reappeared in her warm-up suit, watched her teammates snag silver, and even clowned around dancing with fellow teammate Jordan Chiles. But later she spoke of feeling "lost" after the vault and deciding that she needed to "call it," stressing that she made the decision and not her coaches.

Prior to the Olympics, Biles said, she had been going through some things and using therapy and medicines to cope. But after coming into the Games, stresses began to build up. Especially hard was the sense she was no longer doing gymnastics for herself, but for the rest of the world.

"I know that this Olympic Games I want it to be for myself," she said, tearing up. "I came in and it felt like I was still doing it for other people, so that just hurts my heart that doing what I love has been kind of taken away from me to please other people."

Robert Andrews, a mental training expert who worked with Biles for about four years from March 2013, told Reuters he suspected stress played a large factor in Tuesday's turn of events.

"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."

Biles cited Osaka as an inspiration and said she thought it was good to be talking about mental health in sports.

"We also have to focus on ourselves because at the end of the day, we're human too. We have to protect our mind and our body rather than just go out there and do what the world wants us to do."