If you’re a vulva owner and have had an intense itch between your legs while running, this one’s for you.

(For Runner’s Life on Medium)

You’re on a run, legs on their merry way, but your brain is elsewhere.

Brain: “Alert! Alert! There’s an itch that needs scratching! Seek relief at once!”

Vagina: “It’s me. I itch.”

The itch is so overwhelming you viciously look around to see if anyone would notice if you casually (or enthusiastically) scratched it. It’ll only take a second.

Brain: “Do something!”

Vagina: “It’s not that easy, Brain. Society has a lot of opinions of what you can and can’t do with your vagina. Scratching is a minor offense, but still.”

And maybe you just go for it (who cares, really). Or maybe you pray for a distraction (oh look, baby geese!) so there are fewer people who might witness the deed. Or maybe you try a new stride, ever so slightly crisscrossing your legs or otherwise creatively engaging your thighs to do the dirty work for you.

Regardless of your strategy for getting rid of the itch, not having the itch show up in the first place would be ideal, wouldn’t it?

Vagina: “Humans and their rhetorical questions…Yes, of course I’d love not to itch.”

Vaginal yeast infections (also called vaginal candidiasis) are notorious for causing vaginal itch that can downright ruin your run and keep you writhing in itchiness for days. What gives?

Enter yeast.

Yeast: “Hey! My name is Candida. I’m not the same as bread yeast, just to be clear.”

The Candida brand of yeast is a type of fungus that loves a warm, moist environment (such as your vagina) to curl up in and pass the time by reading a good steamy story (when in Rome, right?). Some yeast normally hangs out in your vagina, and that’s all fine and dandy. But with the right conditions, like moisture and warmth, yeast can grow and grow and eventually cause an infection.

Enter your underwear.

Underwear: “Yes, I’m here. Collecting your sweat. And Vagina’s discharge. Could you run the fan? It’s getting hot and wet in here.”

Yeast: “Ooh, how enticing!”

Yeast is insanely attracted to the moisture-laden haven that is your underwear during a sweaty run (or after, if you’re sitting around in it). Underwear is practically a sauna with a glowing “open” sign that promises growth and rejuvenation as soon as Yeast enters those doors. Going for a long run? Even better. So much moisture, so much time, so much potential for proliferation.

Vagina: “Help.”

The good news is yeast infections are treatable with medication (go to a doctor for a proper diagnosis first). The better news is that they’re also preventable, even for you and your vagina that love a good, sweaty run.

As Cheyenne Buckingham notes in “Bacterial Vaginosis and Yeast Infections Explained — and How to Treat and Prevent Both,” opting for cotton underwear, changing out of your sweaty underwear as soon as you’re back from your run, and refraining from products that promise to restore your vaginal pH balance (“Which I’m perfectly capable of on my own, thank you very much,” Vagina says) are all easy-peasy strategies to reduce the chances that yeast throws a huge party in your vagina, encouraging anyone who identifies as yeast to please come.

Why cotton underwear? Research has shown that synthetic underwear is significantly associated with vulvovaginal infections (of which yeast infections are a type), especially when combined with tight pants.

Vagina: “I mean, I know you look hot in those running shorts that look like bike shorts, but they basically scream infection risk.”

Running Shorts That Look Like Bike Shorts: “Hey! Not fair! I’m not the problem here. Underwear is.”

Underwear: “Hey! I’m the one doing the dirty work. You and your spandex fibers are looking all tight and hot, and I have to absorb whatever comes from Vagina, which can be a lot sometimes. No offense, Vagina.”

Vagina: “None taken. I accept that I have a lot to give. It’s society that’s the problem, but that’s a story for another day. Please continue.”

Okay, so cotton underwear is recommended. But many brands of “athletic” underwear use synthetic, non-cotton material. So what if you have synthetic underwear with cotton lining where your labia lay their pretty little lips? Researchers believe that underwear made with synthetic fabric but with cotton lining doesn’t help — the underwear is still not breathable enough.

Vagina: “I like a cool breeze when I’m hot just as much as you do.”

So wear cotton undies when you run.

What other things can you do to prevent Yeast from growing their commune in your vagina? Change your underwear between runs. If you run a lot, it can be tempting to re-wear underwear from the previous run to push laundry day out by a day, or two, or a week. I get it. However, unlike all your other running clothes that you can get away with wearing a few or more times in a row (what’s a little more stink, really?), your vagina needs a clean sheet, free of yesterday’s crusty discharge and dried sweat, on which to rest when you take your pretty self out for a run.

Go ahead, treat yourself to some new cotton undies.

Underwear: “Yay! New friends!”