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19-year-old Simone Biles is one of the breakout stars of the 2016 Summer Olympics.
Aly Raisman, the all-star American gymnast, is just 22-years-old and already facing down what is possibly her last Summer Olympics. In comparison, Michael Phelps, who is now 31, is still competing this year.
According to one gymnastics expert, the reason many women gymnasts are so young comes down to the demanding and time-consuming nature of the sport.
It's no secret that women's gymnastics highly values youth. During the 2008 Summer Olympics in Beijing, a major scandal occurred in which a few Chinese gymnasts, listed as 16, might actually have been as young as 14 or 15. Meanwhile, the average age of this year's Men's USA Gymnastics team is 25-years-old.
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During the 2008 Summer Olympics in Beijing, some Chinese gymnasts possibly lied about their age.
John Geddert, who was head coach of the 2012 US women's Olympic team, once explained why he thinks most female gymnasts are so young to The Washington Post.
"Without sounding condescending to young women, this is a little girl's sport," Geddert said. "With their body changes and the wear-and-tear everybody goes through, once they become women, it just becomes very, very difficult."
Salon, meanwhile, pointed out that five-time Olympic gold medalist for the former Soviet Union Nellie Kim argued that younger female gymnasts are "lighter and more fearless."
Gymnastics is a very physically demanding sport, and training to be the very best involves a lot of personal sacrifice. Yet, this does not exactly explain why there seems to be more older male than female gymnasts. So
Yim, who started gymnastics at age three, notes that most men don't get started until around ages eight or nine.
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Men's gymnastics involves a lot more upper body strength.
"Typically, the women start a lot earlier than the men," Yim says. "It's just a very demanding sport. And the number of hours you dedicate to it are close to 38-48 hours a week." She added that this kind of wear and tear on the human body is not easy to sustain.
Another factor is that Yim says men often don't mature physically until they are older, and much of men's gymnastics involves a certain kind of upper-body strength that comes with age and experience.
"The men don't end up learning those harder skills until they get to college. And so with their types of events, like rings and a lot of things that require that type of strength, it helps them when they mature and they get stronger," Yim says.
So while aging and growing stronger can be largely beneficial for male gymnasts, the women - who you'll remember have been training longer - are at their peak physical condition much earlier.
Associated Press Simone Biles and Aly Raisman both took home gold in Rio.
But just because a younger athlete's body may be more disposed to competing as an Olympic gymnast, that doesn't mean that gymnastics is a "little girl's sport." In fact, Yim insists that gymnastics is actually a young woman's game and applauds the International Federation of Gymnastics' (FIG) decision to raise the age limit from 14 to 16 made the Olympic competition even better.
The reason? So much of gymnastics is about mental strength, and with age comes the maturity to master the sport. To prove her point, Yim points to 19-year-old Simone Biles.
"A lot of gymnastics is a mental game and I think you noticed that when [Biles] went on beam. I mean, [she was] in second place and all the pressure was on," Yim explains to INSIDER. "You have to be able to handle that type of pressure and really comprehend why you're doing it. I think you have to be an adult and so, I say, young women really thrive in this sport."
But of course, this isn't always the case. Gymnast Oksana Chusovitina from Uzbekistan is 41 and still going strong in Rio.
Perhaps that means we'll see the "Final Five" dominate again at future Olympic Games.