When rhythmic gymnastics made its Olympic debut at the Helsinki Games in 1952, it was a women-only event called “team portable apparatus” that took place within the artistic gymnastics competition. Basically, each team performed a floor routine together using props, or “apparatuses,” chosen from a list of five: ball, club, hoop, ribbon, or rope.

Artistic gymnastics—named in the early 19th century to differentiate it from the less artistic gymnastics used in military training—had been a fundamental part of the Olympics since the first modern Games of 1896, and plenty of gymnastics events had been added and subtracted during that time. “Team portable apparatus” showed up again during the 1956 Olympics in Melbourne, Australia, and then it disappeared.

But unlike rope climbing, club swinging, and other short-lived gymnastics events, rhythmic gymnastics wouldn’t be gone forever. Thanks in large part to the sport’s popularity in Eastern Europe, the International Gymnastics Federation officially recognized it in the early 1960s. Global tournaments began soon after, and rhythmic gymnastics returned to the Olympics—this time separate from artistic gymnastics—in Los Angeles in 1984. Though gymnasts only competed as individuals, a group event was reintroduced for the 1996 Games in Atlanta.

Since then, rhythmic gymnastics has become a beloved (if a bit niche) element of every Summer Olympic Games. It’s much smaller in scope than artistic gymnastics in a couple ways. For one, men’s artistic gymnastics comprises six events (floor exercise, pommel horse, rings, vault, parallel bars, and horizontal bar) and women’s includes four (vault, uneven bars, beam, and floor). There are also separate competitions for individual medals and team medals.

Rhythmic gymnastics, on the other hand, still features just two events: the individual performances and the group performances. And it’s still only for women, though the Olympics website explains that those two events “make up for the two fewer apparatus in women’s artistic gymnastics.”

Because rhythmic gymnastics takes place on the floor, its closest counterpart in artistic gymnastics is the floor exercise. They’re both set to music, they both incorporate elements of dance, and they both—like other events—are scored based on difficulty (the technical side) and execution (related to performance and artistry).

But their differences go beyond the fact that rhythmic gymnasts perform with portable apparatuses and artistic gymnasts don’t. Anyone who’s seen Simone Biles take to the floor knows that flips, for artistic gymnasts, are pretty much the name of the game. While rhythmic gymnasts can do walkovers, cartwheels, and similar skills with their props, aerials and other flips aren’t a part of their program.

“Rhythmic gymnastics is much more acrobatic dance or ballet than artistic gymnastics—and their training is heavily into ballet,” Valorie Kondos Field, who won seven NCAA championships during her 29-year tenure as head coach of the University of California Los Angeles gymnastics team, tells Mental Floss. “Their ability to balance, and their turns—to be able to pull off five and six turns in all these weird positions—comes from heavy ballet training. They have very, very, very little gymnastics training.”

The style of the sports wasn't always so different. Eastern European artistic gymnasts did have heavy ballet training during the 20th century, and that trend caught on in the rest of the world. But as the 21st century drew closer, Kondos Field explains, “artistic gymnastics became more trick-oriented, and because you only have so many hours with your athletes during the day, the first thing to go was ballet.”

It hasn’t completely vanished, however. Kondos Field, a former ballet dancer herself, always kept it in the rotation, partly because artistic gymnasts will get a deduction for un-pointed toes. The ankle and foot control and flexibility learned through ballet can help with launching and landing tricks, too. But in general, ballet is much less fundamental to artistic gymnastics these days than it used to be.

The focus on tricks can also help explain why artistic gymnastics has a much broader fanbase than rhythmic gymnastics. “Personally, I feel that it has a better crossover to people who love sports,” Kondos Field says. “Because the people that I know that are sports fanatics can appreciate someone elevating in the air and doing multiple flips and twists … artistic gymnastics is more hardcore athleticism.” In short, it's the same reason figure skating and swimming (or diving, even) are more popular spectator sports than ice dancing and synchronized swimming.

While rhythmic gymnastics packs a lesser punch, it offers something that artistic gymnastics can’t: the possibility of gender neutrality. “When you look at the majority of sports, the taller, stronger, faster [athletes] will always win,” Kondos Field explains. “But you look at a sport like rhythmic gymnastics where there really doesn’t need to be a separation [between men and women].” Flexibility, balance, precision, and finesse aren’t determined by someone’s height or speed.

At this point, gender-neutral rhythmic gymnastics competitions seem like a long shot. Though men’s rhythmic gymnastics is popular in certain countries—especially Japan and Spain—it’s a very small sport. In fact, it still has yet to be recognized by the International Gymnastics Federation. And if it were ever to merge with women’s rhythmic gymnastics at the Olympics, it wouldn’t be anytime soon. But still, in theory, there could be more gender inclusivity in rhythmic gymnastics’ future.