If you're the kind of gym-goer that prefers milling about in your gym clothes for a full day but never actually making it onto the treadmill, then you might want to listen up.
There's no judgment here; well-made gym leggings are flattering. They hold you in, and if teamed with the right pair of running shoes, allow you to give off the (entirely false) image that you're one of those lucky people who enjoys exercise.
But they're apparently bad for you when wear them outside the gym. According to medical experts, donning our exercise gear for longer than the time we spend working out can cause a bunch of dermatological problems. Which isn't exactly ideal.
Speaking to Mic, dermatologist Dr. Michael Eidelman explains that the fabric used to create exercise-wear doesn't "breathe as well," so causes you to "hold sweat closer to the skin," creating "so much warmth and moisture."
And that, in turn, can lead to skin problems. Like folliculitis, for example, which is when your hair follicles become blocked and then inflamed. This usually happens on the upper back (thanks to sports bras), but you can also get it on your butt if you're a particular fan of spinning or general cycling.
But you'd be getting off lightly if you just got a touch of folliculitis, because apparently gym leggings can also cause yeast infections.
If you were particularly unlucky, you could get vaginitis and other yeast infections thanks to lingering moisture in your leggings around your crotch area. And according to Eidelman, you've got a higher chance of this if you're on antibiotics for the likes of acne.
And nobody wants that when they're trying to do a good deed by exercising, do they? Luckily, Dr Eidelman has a way around it; he recommends hunting down moisture-wicking gym gear, and making sure you shower and change shortly after exercising.
This article originally appeared on Cosmopolitan.co.uk. Minor edits have been made by the Cosmo.ph editors.