NEW YORK — In a typical morning class at American Ballet Theater, the brightly lit studio feels like a laboratory. If you have watched these dancers in performance, you might be surprised at how messy they can be when practicing, falling out of turns, missing the landing of jumps.

On a Friday before “Nutcracker” season, ballet master Vladilen Semenov remained relatively quiet, explaining a combination before stepping back to watch the mixed class of men and women. But the dancers had their own agendas, testing their bodies in experiments of strength, flexibility and physics. A handful of the women, instead of going on point, stayed in slippers to try the men’s steps.

Ballet is widely seen as putting women on a pedestal — male dancers literally lift them over their heads — reinforcing conventional ideas about masculinity and femininity. The pas de deux, or romantic male-female duet, is considered by many to be the art form’s linchpin, but it can seem sentimental, or worse, sexist. Can ballet reflect contemporary ideas about gender? This question is crucial in determining its future standing and reception, especially among audience members unfamiliar with its traditions.

These stereotypes, though, are being challenged on a daily basis in company studios, as ballet dancers everywhere ask why their gender identity should determine the way they dance. Women can jump higher and complete more turns than ever before, skills traditionally associated with male dancers. For their part, men are training to incorporate the stretch and finesse that has long been standard for female dancers.

Rather than distorting the form as some ballet purists fear, dancers who push the gendered boundaries of training “are more versatile and can be stretched in different ways,” said Jonathan Stafford, a ballet master who is overseeing City Ballet’s interim leadership team. Ballet’s codified positions may not change, but this trend is bringing a new dynamic to its old steps.

Ashley Bouder, a New York City Ballet principal, credits the teachers she had growing up for giving her an expansive sense of her capabilities.

“They didn’t see why I couldn’t do what the guys were doing,” she said.

For Bouder, this practice has helped make her jumps famous, defiant of gravity as she seems to hang in the air. Men’s classes, with their slower music (so the dancers can work on lift), have been the crucial supplement to hone this technique. She goes whenever she can.

And she is not alone. Many City Ballet female principals go to men’s class. And those numbers have been growing everywhere, especially at companies with top talent such as the Royal Ballet, the Bolshoi and Miami City Ballet. The advent of strength training for female dancers about two decades ago gave them new scope and range in the studio. More important, the continuing discussion about gender has led them to rethink what they can do with their bodies on their own terms.

Put a woman in men’s class and the effect is liberating, allowing her to escape the image she has cultivated of herself in the studio mirror.

“Some women constrain themselves to get the step right,” said Skylar Brandt, a soloist at Ballet Theater. “Men just grab the floor to get themselves off the ground.”

Brandt is petite, but when she moves across the floor, her body lifts off the ground like a firecracker, an effect she credits to learning from and practicing with male dancers.

“It has made me feel free,” Katherine Williams, another Ballet Theater soloist said, about attending men’s class, “less confined to a certain look I need to maintain as a woman onstage.”

Male ballet dancers must jump high enough to complete two turns in the air in a variety of positions before landing. After spending years perfecting dancing on point, women who try to do the same come up against the limits of their conditioning. Williams decided last year to take all the men’s classes she could. A strong technician and natural jumper, she still sometimes misses the full rotation of the second turn by inches.

“It comes down to how you were trained as a child,” she said.

In the 20th century, George Balanchine, the founding choreographer of City Ballet, led the way, asking women to do what was thought impossible for their physiques. To those wedded to the old image of the art form, the female dancers at City Ballet could hardly be considered “ballerinas” at all, so radically athletic was their dancing.

Now male dancers, too, are extending ideas about their physical capabilities. Men are under less pressure than women to hit 180 degrees with their legs in a leap. But Keith Roberts, a ballet master at Ballet Theater, has started insisting that men improve their split while jumping in variations like those in “Swan Lake.” And it has also “become standard that men’s feet are just as arched and beautiful as women’s, sometimes better,” Roberts said. “They have to be more refined than ever before.”

The first male dancers who became famous in this country were bent on proving they were athletes. Asserting physical prowess was a way to disprove the old stereotype that ballet was not manly.

Today’s male dancers are transforming this legacy. Rather than posting pictures on Instagram of himself jumping or turning, like so many male dancers do, Carlos Gonzalez of the Ballet Theater corps poses in high extensions.

“I want to show other guys that they can do this, too,” he said.

It is not unusual for women to lift their legs above their heads, but when a male dancer does, the effect is arresting.

To do so, men have to learn from their female colleagues. Studying women “shaped the way I dance,” said Jose Sebastian, also a corps member at Ballet Theater. “I saw things the women had that I needed to apply to myself.”

There is a reason choreographers can now highlight male dancers’ bodies in innovative ways. Many are acquiring the stretch and polish usually demonstrated by the female body in ballet, movement qualities customarily used to convey vulnerability and emotional depth.

Point work is a separate issue. Some men take it up just to strengthen their ankles and propel their arch.But today’s male dancers do not want to go on point as a caricature of femininity, as has historically been the case with drag roles. As it stands, “they don’t have access to proper training,” Bouder said. “To get good — really good — at it, to be taken seriously, they would have to pay out of pocket for private lessons.”

Fear of injury can discourage dancers from training across genders. Without the usual apprenticeship, point work can be dangerous. And no amount of technical study can prepare women to try men’s jumps. Going for double the torque and lift needed for two turns in the air is a huge shift, and botched landings often result in twisted ankles.

Women are even more constrained when it comes to men’s partnering moves.

“If I beefed up enough to be able to lift a woman above my head, or even just partner her properly when she’s balancing, I would not look good in a tutu,” Bouder said.

Brandt too said that because most women have less upper-body strength, they “fake” lift, doing so for a few seconds as their partner jumps into it.

A dancer’s skill set is ultimately dictated by the job market. Girls do not learn boys’ jumps because “they’re not asked to do them in 99 percent of the repertoire,” Stafford said. He added that should this change, the curriculum will be adjusted.

As it probably will.

In 2017, Justin Peck, City Ballet’s resident choreographer, made headlines when he included gender-neutral roles in “The Times Are Racing,” showing that male and female dancers could swap roles. For his “Principia,” debuting Jan. 31 as part of the company’s winter season (through March 3), Peck has incorporated a pas de deux, but without the usual romance. The new duet instead explores things like “teamwork, construction, opposition, physical tension and compromise,” he wrote in an email.

Bouder notes that it is precisely this shift that will lead to a trickle-down effect.

“If you have established choreographers creating gender-neutral roles and same-sex dances, then the kids coming out of schools will need to be capable of performing them,” she said.

Back in the Ballet Theater studio, Connor Holloway, a corps member, and Sebastian were lifting their legs out to the side in one of ballet’s age-old steps, as they warmed up at the barre. They did not quite hit the height of the female dancers surrounding them — but they were close, and their feet are just as curved.

“Before I got into the company,” Holloway said, “I thought I maybe needed to butch it up, because that’s what people wanted to see.” But he attributes landing his job in 2015 to “knowing and being secure in who I am — not thinking about labels.”

That stretch, polish and struggle he showed in the studio to keep the leg taught in the air might be expected from a woman. But it was arresting on a man. It made you want to watch him. It makes ballet look new again.

This article originally appeared in The New York Times.