The Best Underwear for Workouts, Tested By a Gear Editor and a Gynecologist

Out of all the options out there, we love the Only Hearts 100% Organic Cotton French Bikini best. The classic shape is minimal and goes with any workout apparel, there are a ton of color selections, and it’s made from a super breathable fabric. Plus, the minimal seams and super-soft fabric are some of the comfiest on this list, whether I have this pair on under tight leggings or baggier sweats.

We love that these undies stay in place no matter the workout. It’s made with an elastic waistband, which prevents it from riding up or down. From gentle yoga flows to intense interval training, it moves with you through every bend and sprint. Since the elastic waistband is so slim, it also doesn’t dig in, which can sometimes be an issue with bikini-style underwear.

A detail to keep in mind is that cotton doesn’t dry out as quickly as other synthetic undies I’ve tested, like the lululemon UnderEase Mid-Rise Thong. Dr. King says that cotton is extremely breathable, but it isn’t the most sweat-wicking option. If you run on the sweaty side, cotton may not be for you. But for less sweaty gals and quick workouts, this pair is a clear winner.

Low-rise gals, rejoice: this 100-percent cotton thong has a dipped front so you never have to worry about it peeking through your leggings or shorts (huge plus!). Plus, it’s super stretchy and never constricting. Wearing this thong literally feels like you have nothing on.

When I run, I want a pair of underwear that won’t show and will be comfy after long outings. The Skims Dipped Thong is super discreet, flattering, and stays in place during my morning and afternoon runs. The small amount of elastane maintains stretch, and the cotton is so soft, I almost forget I have it on! I also love how smooth this pair is—I can wear it under leggings without worrying about showing panty lines, and just focus on my run instead.

The diverse size options here mean basically anyone can find a pair that works for their body, and although the color options once again don’t feature anything too spicy, I actually love the calming, earth-toned palette Skims went with. If you’re a runner who loves a silky-feeling thong, this is your best bet.

Buying in bulk is a great option for tried-and-true products that I just can’t get enough of. That’s why I love this bulk pack of cotton thongs for working out: they’re affordable, comfortable, and are made with organic fabrics. Plus, this underwear is super comfy!

When I shop for underwear, I prioritize materials over everything. That’s why I love this underwear from Quince: It’s made with 95-percent organic cotton that feels softer than more expensive options I’ve tried. I also love the fit, which provides minimal coverage at the back and hips; I almost forget I have it on. I throw this on most for running, where I experience the most movement and potential chafing.

The size options are fairly run-of-the-mill: XS—XL. The colors are basic as well, so if you like something a little more feminine or playful, these may not be for you. But aside from the neutral tones and limited sizing, there’s one more factor that sets these apart from the competition: the price. Quince has built a reputation for manufacturing quality goods for a fraction of the traditional retail price. I love that I can score a six-pack of thongs for the price of one luxury pair…and that I know they’re quality. It’s a win-win!

Working out during your period comes with its own set of challenges: cramps, lower energy, and the risk of bleeding through your favorite leggings. Knix’s period underwear is the holy grail for gals that want peace of mind while working out during their menstrual cycle. The brand’s patented cotton and polyester pad stands up over time and absorbs like a champ. It comes in three levels of absorbency, with the most heavy-duty pair handling up to 4 super tampons’ worth of liquid.

This option is snug and secure without being restrictive during workouts like yoga or Pilates. The proprietary blend of nylon, spandex, and polyurethane film offers ample stretch and a snappy feel. Plus, the bonded edges provide extra protection against leaks while protecting against chafing.

“These are so great for working out during my period,” says one tester. “Although I still wear a Diva cup or tampon on my heavier days, on my lighter days I can wear these and confidently go through a whole workout without worrying about spotting, bleeding through, or discomfort.” The Light option can absorb up to three regular tampons’ worth of liquid, while the Moderate option can absorb up to four super tampons’ worth of liquid, so if you’re heading to a workout class or on a moderate run, you’ll be fine. But because of the minimal coverage (it is a thong, after all), you may want to pair them with a tampon, just to be safe.

This workout underwear from lululemon has a truly seamless design and an impressive moisture-wicking fabric that kept testers feeling fresh through even the toughest exercises. Speir loves the super soft, barely-there feel of this sweat-wicking option. As a bonus, bonded seams and a delicate cut mean no irritation or VPLs (visible panty lines).

While most lululemon panties are made with synthetic fabrics, the UnderEase Thong is made with modal. It’s a wood pulp-based fabric with great breathability, and we find that this pair dries quickly. It's also super comfy and easy to maintain: I've thrown this in the wash countless times and found it still maintains its color and shape.

That's why I love it for high-intensity workouts and long travel days.
Wohlner is also a mega fan of the brand's underwear. "It’s my go-to underwear when I know I'll be sweating because it wicks away moisture and keeps me feeling cool and dry," she says. "Plus, it’s completely invisible under leggings."

Made with almost 100 percent Tencel lyocell (a more durable and sustainable lyocell), this barely-there thong is great for high-intensity workouts — it doesn’t move or get in the way. Made from 95 percent Tencel and five percent elastane (for a little stretch), this thong is ultra-soft, super lightweight, and extremely comfy.

The Soft Touch Thong has a wider waistband than some of the other options I’ve tested, which prevents it from pinching my skin or rolling down. I love that I can wear it under tight leggings without worrying about any distracting lines, and there’s just enough stretch that it stays in place without digging in.

This pair is less than twenty bucks, making it more affordable than some of the other options on this list.

Merino wool is one of the best materials to look for in a pair of workout underwear, and Branwyn's Essential Bikini is my favorite merino wool option. It dries out very quickly, even when I’m super sweaty. I love that I don’t have to worry about wearing these straight from the gym to brunch if I’m in a hurry.

The seamless construction means no weird pinching or discomfort. The four-way stretch (from the spandex in the fabric) means it moves in every direction without feeling restrictive. In fact, this is the most flexible underwear I’ve tested during my runs. Each piece is dyed in small batches, making every pair unique.

One major caveat I have to mention when it comes to the Essential Bikini, and Branwyn in general, is the sizing. I’m typically an XS, but in some pairs I’ve found myself in a medium (especially near that time of the month). To be safe, I would encourage anyone interested in these to go at least one size up from their normal size.

If you don’t love the feeling of a thong, boyshorts are a fantastic alternative because they provide more coverage with minimal chafing. Our experts recommend this pair from Boody. We like that it is made primarily with viscose from bamboo, another wood pulp-based fabric option that is super soft and smooth, even after years of wear.

This full-coverage style won’t ride up because of its mid-rise cut and flat waistband, which makes it ideal for workouts like Pilates, yoga, and even walking. The sporty style is seamless and full-coverage, so it’s appropriate for almost all occasions, from working out to daily wear.

This pair does include some synthetic materials like nylon, but they’re used wisely to add stretch and durability to the boyshort. The size range of this pair is narrower than other options on our list, so for those on the edges of the size spectrum, this may not be the brand for you. However, if you’re looking for a sporty-chic option that is comfortable and isn’t too pricey, the Boyleg Briefs are a great option.