TOKYO - Simone Biles arrived in Tokyo as the star of the U.S. Olympic movement and perhaps the Games themselves.

She convinced herself she was prepared for the pressure.

Only, as the women's gymnastics team final approached she felt something was off and the American star withdrew from the competition following one rotation.

That opened the door for the team of Russian athletes to win gold for the first time in nearly three decades.

Biles says "We also have to focus on ourselves, because at the end of the day we're human, too."

She adds that we have to protect our mind and our body, rather than just go out there and do what the world wants us to do.

Biles has become an outspoken advocate for athlete's rights and the importance of proper mental health.

She is the latest in a series of high-profile athletes, including tennis star Naomi Osaka, who have used their platforms to discuss their mental heath struggles.

A subject that was once taboo has become far more accepted and embraced.

U-S Olympic and Paralympic Committee CEO Sarah Hirshland applauded Biles for prioritizing her "mental wellness over all else" and offered the organization's full support.

USA Gymnastics women's program vice-president called Biles' act "incredibly selfless."