"As hard as it was to believe it's really not that hard to understand. And it was without question, the right thing to do," said the former Team USA figure skater, who is hosting a show called "Talkin' Tokyo" during the Olympics. "The extra scrutiny that female athletes face and specifically Black female athletes face is unfathomable and unfair."
Rippon posted a full version of his message on Instagram on Thursday.
"Simone, you are more than just a gymnast," he wrote in the caption. "We’ve never met but I hope you feel how loved and admired you are."
On Tuesday, Biles withdrew from the women's gymnastics team final after performing once on the vault, saying later she wasn't in the right headspace to compete. A day later, she pulled out of the individual all-around competition. Her teammate Sunisa Lee won gold in the all-around Thursday, becoming the fifth straight U.S. gymnast to do so.
"Physically, I feel good," Biles told Hoda Kotb on TODAY Tuesday. "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."
"Imagine for one moment that every event you compete in every move you make, the way you wear your hair, every word that comes out of your mouth is met with immediate feedback from anyone who might want to say anything," Rippon said in his message. "It sounds completely draining and mentally exhausting. Now imagine that, well, under that kind of scrutiny, your body starts to fail you in one of the biggest moments of your career.
"Stress and pressure, have a price. The body keeps score," Rippon said. "And in gymnastics, mental and physical health are intertwined."
After her withdrawal, Biles made extensive comments emphasizing the importance of athletes taking care of their mental health.
"We also have to focus on ourselves, because at the end of the day we're human, too," she told reporters on Tuesday, according to the Associated Press. "We have to protect our mind and our body, rather than just go out there and do what the world wants us to do."
In a series of Instagram posts on Friday, Biles answered fans' questions about her mindset, including her comments about experiencing a bout of the "twisties" — a term gymnasts use about losing awareness in midair.
"literally can not tell up from down. it's the craziest feeling," she wrote.
As a former fellow Olympian, Rippon said he could relate. During his figure-skating career, he said he would sometimes feel "off" — a result of nerves, adrenaline or stress. The difference, he said, was that his "life wasn't in danger."
"The difference is that in men's figure skating, you're always upright, every element we do is just up and down. My life wasn't in danger. If I missed a jump, the risk of me landing on my head or my neck was very low," Rippon said.
Rippon said the sports industry was too used to "applauding people who ignore limits."
"While it is absolutely heroic, to push through limits in certain circumstances, it is just as heroic to prioritize your well-being when the world expects something different from you," he said.
Biles, a four-time Olympic gold medalist, said she was inspired by Naomi Osaka's decision to put her mental health first and withdraw from Wimbledon last month.
According to a Team USA Gymnastics statement Wednesday, Biles will be "evaluated daily to determine whether or not to participate" in next week's events.
"As a culture, we need to redefine what it means to be brave and what it means to be strong," Rippon said. "And I'm very grateful that Simone Biles is showing us the way."