During a poolside interview in Rio on Saturday night, Chinese swimmer Fu Yuanhui spoke frankly about the fact that she had her period during an Olympic event—smashing a longstanding sporting taboo.

After her team placed fourth in the women's 4x100 medley relay, the 20-year-old swimmer was crouched down, visibly in pain. She stood as the reporter turned to her. "I feel I didn't swim well today. I let my teammates down," said Fu, who won bronze in the 100-meter backstroke last week.

When the commentator asked if she had a stomachache, Fu clarified, "It's because I just got my period yesterday, so I'm still a bit weak and really tired. But this isn't an excuse for not swimming well."

Fu's candidness in the interview—which quickly went viral—is so great because it's helping to normalize the subject of menstruation in sports, a topic that's long been ignored, despite recent efforts to take down the barrier.

That this taboo was broken by a Chinese swimmer is especially notable since, as the New York Times reports, menstruation itself is a taboo subject in China, and tampons are much less common there. One industry survey found that only 2% of Chinese women use them.

RELATED: The 9 Best Workouts to Do When You Have Your Period

What's more, Fu's candor is shedding light on a pervasive public health myth: As news of her interview spread on China's social media platform Weibo, some commenters were arguing that it's unhygienic for a woman to swim on her period, according to the Times. This fear isn't limited to China: Earlier this week, Today reported on a viral photo of a sign posted at a pool in the country Georgia, warning women not to swim during their periods.

But this belief "really is a myth," confirms Angela Gonzalez, MD, an ob-gyn at Montefiore Health System in New York City. Blood-borne infections can't survive in chlorinated water, so there is no risk of infection spreading via blood in a pool. "You can continue all your regular activities with menses," Dr. Gonzalez assures.