When American gymnastics superstar Simone Biles was born in 1997, Oksana Chusovitina had already won five world medals and an Olympic gold.

When Biles' teammate Laurie Hernandez was born in 2000, Chusovitina was already the mother of a young son.

When Gabby Douglas made her Olympic debut in 2012, Chusovitina was competing in her sixth Games.

A list like this could go on all day, because there might be no other athlete in history who has defied the odds, and Father Time, like the 41-year-old Chusovitina. She is in Rio for her unprecedented seventh Olympics.

Aly Raisman, the U.S. team's captain, is 22 years old, and she's returning for her second Olympic Games. Her teammates refer to her as "Grandma Aly" because of her age and habits. And while she may be considered old in the sport, she has quite a ways to go if she wants to match Chusovitina as the oldest woman to ever compete at the Olympics in gymnastics.

Chusovitina was born in 1975 in what is now Uzbekistan, and she learned gymnastics through training in the rigid Soviet Union system. She won the all-around at her first major competition -- the USSR's junior national championships -- as a 13-year-old in 1988. In 1991, at her first world championships, she earned three medals, including the gold on floor. To win that title, she mounted with a full-twisting double layout -- a move so difficult that it was named after her. It's still considered so hard that Biles, the favorite to win the 2016 Olympic title on floor, will use the same skill in her first tumbling pass -- 25 years later.

Ironically, though, Chusovitina thought her career might be over in 1991 after the fall of the Soviet Union. Uzbekistan was suddenly an independent country -- without the resources needed for developing elite gymnasts. A Unified Team was created for athletes from the former Soviet nations for the 1992 Barcelona Games, and Chusovitina made her first Olympic team in 1992.

Standing at the opening ceremony with her teammates remains her favorite Olympic moment to this day. "It was just so amazing to see with your own eyes," she recalled, speaking through her translator, Svetlana Boguinskaia, who is a longtime friend, a teammate from the 1992 team and now an assistant coach for Chusovitina.

"When I saw the person with the arrow shoot the arrow into the Olympic rings and they went on fire as the ceremony started, I couldn't believe it. It's still my best memory," Chusovitina added.

Despite the political turmoil and uncertainty at home, the Unified Team won the gold medal. And it was the beginning of one of the most storied Olympic careers of all time -- one spanning 24 years (and counting) and three countries.

It's a career even her peers can't comprehend. "I can't even fathom how it's possible, and I'm 24," said retired gymnast Shawn Johnson, who won gold in the 2008 Olympic balance beam.

"I would compare her career overall to how amazingly good Simone [Biles] is. Just like how people are assuming at this point Simone will win all-around gold in Rio, it's assumed every year Oksana will be there. And it's assumed every year she's going to medal.

"No one even knows how old she is anymore because it seems like she's been to the last gazillion Olympics. She's incredible. She is a legend."

After her successful first Olympics, Chusovitina returned to Uzbekistan and began training and competing for the new nation. She competed at the 1996, 2000 and 2004 Olympics for her native land, and won five world medals on vault during that time -- including the gold medal on vault at the 2003 world championships. She became a beloved figure in her home country, earning the title of "Honored Athlete of the Republic of Uzbekistan," and she was even commemorated on a postal stamp in 2001.

Chusovitina married fellow countryman and Olympic wrestler Bakhodir Kurbanov in 1997, and the two welcomed their first and only child, a son named Alisher, in November of 1999 -- less than a year before the Sydney Games. While Chusovitina managed to balance motherhood with training and competing, Alisher was diagnosed with leukemia in 2002. The distraught family moved to Cologne, Germany, for his treatment.

Oksana Chusotivina began competing for Germany in 2006, while her son, Alisher, now 16, received treatment for leukemia. Today, Alisher is cancer free. Vladimir Rys/Bongarts/Getty Images

While there, Chusovitina began training with the German national team and ultimately applied for citizenship. In 2006, as her son continued his battle against cancer, she began officially competing for her adopted country. During the Beijing Olympic Games in 2008, the then-33-year-old won her first individual Olympic medal -- a silver on the vault.

But despite the "exciting" accomplishment, Chusovitina's best and most proud moment came when she returned home. Shortly after the Games, the doctor called and told her Alisher was finally leukemia free. "It was the greatest news of all," she said.

"Medals, no medals, it really doesn't matter when you hear this news. [No] medal could compare to this type of phone call. When your son is healthy, you can't compare any athletic achievements with that."