If you’re the type of person to wear underwear with everything—a very normal type of person to be, in my opinion—you might start to wonder what’s going on with running shorts and workout leggings. Sometimes loose men’s shorts will have a snug-fitting liner, or certain women’s styles will have a crotch gusset made of a different material than the rest of the shorts. Am I supposed to wear these without underwear, you might wonder? The answer is, in many cases: yes.
It’s a common question, though. On Reddit, the subject gets discussed on the running forums, the women’s fitness forums, the “no stupid questions” sub, and more. The ensuing discussion often involves two groups of people (underwear wearers and underwear non-wearers) reacting with shock to the fact that the other exists.
So let’s see if we can break this down a bit. Anybody can wear any shorts they like, in my opinion, but they tend to be sold in “men’s” and “women’s” styles, so here’s what you can expect to find on each side of the aisle.
What to expect in men’s running shorts
Men’s running shorts often have an underwear-like liner “to hold your balls in place,” as one helpful redditor put it. Why not just wear normal underwear? Well, you can, but running shorts are often designed to be comfortable and sweat-wicking, so why ruin that engineering with your regular ol’ cotton undies? Think of the liner as free underwear optimized for your running needs.
The liner also helps to prevent chafing, as this discussion among ultrarunners (people who run more than marathon distances) reveals. Styles vary, from minimalist liners to full compression shorts. Snug-fitting running tights will often have a windproof panel in the front, which is another sign they’re meant to be worn commando.
If your running shorts don’t come with a liner, a common recommendation is to wear them with compression shorts—or to go back to the store and get a pair that has them built in.
What to expect in women’s running shorts
There’s less of a consensus with women’s shorts and leggings: some people wear underwear with them, and some don’t.
In general, if there’s a snug-fitting liner in your loose-fitting shorts, they’re meant to be worn commando. And if there’s a crotch gusset (a strip of doubled up, different-textured fabric right between your legs), that’s another sign they’re designed to be worn without undies.
Many runners go without underwear, and often find that the waistband or thighs chafe less when they do; the pairing of the shorts liner and the extra layer of underwear (especially when sweaty) can be a bad combination.
But if you’re more comfortable with underwear than without, wearing it may make the shorts last longer (especially if you’re worried about stains) and can also allow you to wear the shorts more than once without washing, if you’d like. Consider buying underwear that is made for running or exercising; some runners report that merino underwear, for example, wicks sweat better than other materials.
When it comes to regular leggings, rather than purpose-made running shorts, you may want to do a “squat check” to be sure that the leggings won’t be see-through when stretched. (Use a mirror, your phone camera, or a trusted friend to find out.) Also try on the leggings sans underwear before you head to the gym: some aren’t designed to be worn commando, and might have seams in uncomfortable places.