KALYANINO, Russia, July 30 (Reuters) - When Soviet gymnast Larisa Latynina competed at the 1964 Tokyo Olympics, her team lived in military barracks with communal bathrooms. At Tokyo 2020, Simone Biles and her U.S. team mates are staying at a hotel. Almost six decades have passed since Latynina, now 86, clinched gold in the team event and floor exercise - two of the nine Olympic gold medals she would win for the Soviet Union - at the first Summer Games held in Tokyo. The world has changed since then, from Olympic accommodation to the emergence of concern for gymnasts" mental well-being. Biles, a four-time Olympic champion, had been set to challenge Latynina"s record of nine Olympic gold medals for a gymnast and perhaps break her record of 32 combined Olympic and world championship medals. But on Tuesday, the 24-year-old American completed one vault at the start of the women"s team final before abruptly withdrawing, citing mental health concerns. She also withdrew from the all-around final. At her home two hours outside of Moscow, Latynina watched as Biles stunned the world with her exit. "In our day that would have been unacceptable," said Latynina, the winner of 18 Olympic medals. "I can"t imagine how that"s possible." Biles" move, inconceivable in the Soviet era or even a few years ago, has brought mental health into focus at Tokyo 2020, where the U.S. gymnast has generally received an outpouring of support. Although Latynina could not have fathomed such a scenario in her era, she acknowledged that over the years her sport has become more physically - and psychologically - gruelling. "What we did is not comparable to what modern gymnasts do," she told Reuters on Friday. "Looking at what gymnasts today do, I"m a little afraid. Would I have started gymnastics or not?" Latynina did not remember the Soviet gymnastics team turning to psychologists or other formal tools to improve concentration and mental performance. She relied on encouragement and accolades from coaches and teammates. To soothe her nerves, she would stand on her tiptoes, close her eyes and remain still. "My coach would always say it doesn"t matter in which position you finish," Latynina said. "The most important thing is doing what you can." There was pressure, of course, to win medals for the Soviet Union, which used elite sport as a tool to boost its international prestige. But Latynina said Soviet authorities" desire for the country"s athletes to top medal tables was not perceived as coercion. "We were trying ourselves not to let our country, our people down," she said. "We would cry when our flag was raised and national anthem played."