A Chinese swimmer mentioned her period like it was no big deal. Because it wasn’t.

Chinese swimmer Fu Yuanhui defied a major sports taboo, and won legions of internet fans, for doing something pretty simple: actually admitting that she was on her period, and that it was affecting her physically.

Fu, who is already a viral favorite in China for her animated facial expressions and candid sense of humor, was approached by a journalist Sunday after China finished fourth in the women’s 4x100-meter medley relay.

Fu hadn’t swum her best, and was also clutching her abdomen in obvious pain. When asked about it, she replied matter-of-factly: "My period came yesterday. I'm feeling a bit weak and exhausted, but this is not an excuse."

That little remark got a big response online, and people praised Fu for her candor and for opening up an important conversation.

Fu isn’t the first female athlete to mention her period in public; British tennis player Heather Watson also made waves when she did so in 2015. But it’s still rare enough to be a big deal — and it’s an especially big deal for women in China.

Shockingly, as Zheping Huang pointed out at Quartz, many Chinese people literally didn’t realize that it was possible for women to swim on their period. That’s because tampons are basically taboo in China. Few women use them because they’re afraid a tampon might break their hymen and thus compromise their virginity. (It’s possible, but very unlikely, for a hymen to break because of a tampon.)

Breaking period stigma is important for women everywhere, athletes or no

The stigma and shame that surrounds women's periods, as a recent Newsweek cover story by Abigail Jones explained, has a pervasive negative impact on women's lives. That ranges from everyday embarrassments and indignities like lousy tampon machines that don't work in women's restrooms to more severe consequences like girls in the developing world dropping out of school once they start menstruating.

Women's periods are routinely used as a weapon to mock them as emotionally unstable, as we saw with Donald Trump's "blood coming out of her wherever" comments about Fox News anchor Megyn Kelly.

All of this is why more feminists are speaking out and conducting activism around periods, from bloody Instagram photos and marathon runs to pushing to repeal sales taxes on tampons.

The fight against period stigma has also intersected with the fight against abortion stigma, with women calling Indiana Gov. Mike Pence to talk about their periods in protest over a bizarre anti-abortion law that would require them to bury or cremate the results of a miscarriage.

"When girls first start their periods, they embark on a decades-long journey of silence and dread," Jones wrote. But as feminist icon Gloria Steinem famously satirized, the opposite would probably be true if men could menstruate — they'd "brag about how long and how much," probably using it as an excuse to justify their dominance.

For women, though, period stigma is used to justify discrimination against them. That’s why it’s so important for role models like Fu to talk about it like it’s normal — like the routine experience for half the world’s population that it is.