Mikaela Shiffrin and Lindsey Vonn have emerged as two of the most recognizable faces of the 2018 U.S. Olympic team.

Shiffrin burst onto the scene during the 2014 Sochi Games when the 18-year-old became the youngest athlete in history to win the Olympic slalom event. In three events in PyeongChang, she has captured a gold medal and a silver. Vonn, widely considered the greatest female ski racer in the world, earned a gold medal in the 2010 downhill and a silver medal in the super-G before being sidelined for Sochi with an injury. This week, she captured a bronze medal in the women’s downhill — making her the oldest woman to win an Alpine medal at the Olympics — before she missed a gate in the slalom portion of the combined, ending her Olympic career without one last gold medal.

Their skiing successes have earned them global recognition, lucrative sponsorship deals and public adoration. But while no one would dispute their talent, their appearances have helped separate them from the other talented athletes in the Olympics. Shiffrin and Vonn are tall, slim, blonde and white — embodiments of what Western culture considers desirable physical attributes for female athletes.

Their looks point to one of the more overlooked hurdles confronting female athletes aspiring to compete in the Olympics: the often overt criticism muscular female athletes confront because they do not look like the model of womanhood exemplified by Shiffrin and Vonn. That criticism not only limits lucrative opportunities after the Games — crucial for athletes competing as unpaid amateurs — but also has, at times, affected women’s ability to compete at the Olympics.

Instead of being lionized, muscular athletes confront vilification and whispers about their gender. So strong are these criticisms that the International Olympic Committee launched mandatory sex testing in 1968 to verify the sex of female athletes. The testing started thanks to a toxic mix of Cold War animosities that fueled doubts about strong Soviet women and the successes of athletes of color who failed to conform to conventional notions of acceptable Western femininity. Critics whispered innuendos that these athletes were not “real” women and persuaded the IOC to institute sex verification.

Even in the days before mandatory sex testing, worries about muscular women affected female Olympians. During the 1920s and 1930s, Olympic officials conducted a handful of on-site, suspicion-based tests on women deemed too strong, successful or masculine. Then, beginning in 1948, the IOC started requiring a doctor’s note verifying the sex of all female competitors.

But the Cold War, with its heightened stakes for all international sporting competitions, demanded far greater verification.

The Soviet Union’s Olympic successes in the early Cold War years — the Soviets topped the Americans in the winter and summer medal counts in 1956, 1960 and 1964 — infuriated American fans who contended that the muscular Eastern European women fueling these victories were cheaters. According to The Washington Post’s Shirley Povich, testing was required because “some of the muscular Russian and Polish babes were not quite as feminine as they declared in the Olympic registry.”

The International Association of Athletics Federation first answered the call for compulsory testing of female competitors. In 1966, the IAAF tested track and field participants via the “nude parade,” a humiliating experience for women who had to display their bodies in front of a panel of doctors. One year later, the IAAF instituted the Barr body test, a technique that checked competitors’ chromosomes.

At the 1968 Grenoble Winter Olympics in France, the IOC implemented testing of its own. It selected 50 athletes by lottery to undergo the Barr test, despite objections from medical practitioners. Geneticists warned that signaling out chromosomes as the lone criteria for determining a person’s sex was not only scientifically incorrect — because sex is composed of a variety of factors — but also unethical.

American journalists had a very different problem with this testing scheme. They believed that the testing ought to focus solely on the Soviet and Eastern European female Olympians; they deserved the scrutiny, they felt, because the femininity of the all-white U.S. women’s team obviated any need for testing them. An Associated Press report noted that the 1968 female skiers were “among the most beautiful and feminine in the Winter Olympics” and were “happy that they look like girls.”

Several accounts focused on 18-year-old Karen Budge, a “willowy blonde . . . with a figure of a Las Vegas showgirl,” who ended up not competing because of a dislocated shoulder. The Post’s Povich suggested that verifying Budge’s sex would be pointless, as she was a “peachcake” with “blue orbs that would melt an entire ski slope or set off a whole cantata of wolf whistles.”

American coaches, athletes and officials — including Budge herself — were similarly miffed by the testing regime. One official argued, “They should test the most obvious or all of them . . . not go down the list and pick them out of the blue.” By “most obvious,” he presumably meant those who did not fit within the bounds of acceptable femininity.

No Olympian failed the test at Grenoble. Still, the testing continued, outliving the Cold War that birthed it.

Only in 1998, after an international outcry and a recommendation from the IOC Athletes’ Commission, did Olympic officials finally halt compulsory verification. The names of athletes who “failed” the IOC’s tests have been kept confidential; however, estimates suggest that one or two Olympians per Olympics were likely unfairly disqualified from competition thanks to these dubious tests.

Even after the end of compulsory testing, suspicion-based testing continued. From 2000 to 2010, the IOC maintained the right to check any competitor it found “suspicious.” In other words, Olympic officials could require a test based on an Olympian’s physical appearance‚ a standard that punished strong-looking women who violated Western norms for femininity.

With the Cold War over, a racial dynamic has become the most prevalent theme in the rumors swirling around these women.  Most notably, during the 2016 Rio Olympics, many people voiced cruel criticisms of South African runner Caster Semenya. Semenya has been in the public spotlight since 2009, when she won the 800-meter race in the track and field world championships. Her times slowed during the 2012 Summer Olympics, which many people suggested was a result of the IAAF’s hyperandrogenism policy, which required women’s naturally produced testosterone to be below a certain threshold to compete as a woman.

After Semenya claimed gold in the 2016 800-meter event, followed by Burundi runner Francine Niyonsaba and Kenyan Margaret Wambui, many people questioned their performances, not even trying to cloak the racism and assumptions about femininity underpinning their complaints. Poland’s Joanna Jozwik, the fifth-place finisher, epitomized this mentality, telling reporters, “I’m glad I’m the first European, the second white” to cross the line.

The IOC suspended the hyperandrogenism standard for the 2016 and 2018 Olympics; yet, unlike the doubts voiced in Rio, few have worried about its absence in PyeongChang. As has been the case in most Winter Olympics, accusations of gender fraud remain tellingly absent.

This is likely because most competitors look like Shiffrin and Vonn.

Many Americans have sat on the edge of their seats cheering each run that Vonn and Shriffin have skied during the Olympics, and they received attention and adulation from fans and media alike. While we should absolutely recognize their achievements, we shouldn’t lose sight of the fact that one reason they are so celebrated is because they conform to our narrow conceptions of what female athletes ought to look like. If they didn’t, they might face questions about their success being too good to be true.