I Squatted, Sprinted, and Planked to Find the Best Workout Underwear

I wouldn’t necessarily reach for a lace thong for exercising, but I have plenty of friends who told me they sometimes work out in Hanky Panky. And honestly, these Pact underwear were surprisingly comfortable. I appreciate that they’re mostly made of organic cotton with a dash of elastane for stretch. The lace isn’t scratchy at all, but I wouldn’t go so far as to say it has a barely-there feel since that lacy side detailing is textured and the raw edges feel like they’re catching slightly under my leggings.

I tested the InvisiWear thong for the first time for this story, and I must say they’re a smidge more undetectable than my go-to UnderEase, listed below. The only holdup is the fabric makeup: 72 percent nylon and 29 percent Lycra, though the gusset is 100 percent cotton. It’s a shame because these are excellent in terms of barely-there feel, and since the brand says they’re designed for yoga, they feel incredibly smooth under leggings or shorts and are so weightless that I never noticed them digging in or bunching up too much, even when that thin piece of fabric is between my cheeks in down dog.

Here’s an elastic-free option from Athleta’s BodyMove line. The fabric is a blend of nylon and spandex with a breathable cotton gusset, and while I found the material to be very lightweight and airy, the nylon inclusion being more than half — 56 percent, to be exact — turned me off.

Made with mostly Tencel (a brand of lyocell fiber) and elastane, this Organic Basics thong is soft and breathable. Lyocell also has solid moisture-wicking capabilities, which can prevent chafing or dampness during intense workouts. I just didn’t love the design, since the waistband is rather prominent: It’s a visible elastic band that’s emblazoned with the Organic Basics logo.

If you prefer higher-waisted workout underwear, then consider these Uwila Warrior briefs. These are definitely the most secure-feeling underwear I tried with plenty of front and rear coverage. The leg openings are lower-cut, so there’s more fabric at the hips, which felt slightly off on faster runs and is the reason they weren’t among my top selects. But I was never unhappy to wear them in terms of silky-soft comfort and being VPL-free. They contain a combination of nylon and spandex, but the gusset is 100 percent cotton.

I’d never tried merino-wool underwear before working on this topic, but I’m so glad it forced me into trying this odor-fightingandtemperature-regulating natural fiber. The merino-wool-based thong from Woolly is flimsier than the Branwyn thong below since it has an elastic-free waistband. Don’t get me wrong — I still reach for the Wooly thong because it’s thinner and only contains 5 percent elastane. But I wished it contoured more tightly over my hips and along the front. It seems the front panel has some unnecessary fabric, so for next time, I might try sizing down from my regular size S. The underwear’s breathability and quick-drying nature are also high points, but I wanted something that didn’t bunch up in my crotch area.

Tommy John started off making men’s underwear but launched a women’s line back in 2018, which I was not familiar with. I decided to give them a try since my fiancé is a fan of the boxer briefs made from the same fabric. The modal and spandex material is plenty soft, but for some reason, I think my sizing might have been a bit off — though I took my normal size S — as these bunched up slightly in the front. Had the sizing been better, I think these could have been a top contender, and I’m planning on sizing down when my underwear drawer needs a refresh in the near future.

I’ve repurchased the UnderEase mid-rise underwear from Lululemon several times. The blended modal and Lycra material is super thin and has a skinlike feel, especially since the seams are all very flat and don’t dig in. These show very minimal VPL in leggings, but I typically wear them with unlined running shorts. For bikini-style workout underwear, these are pretty nice, and the material isn’t terrible with modal, which is a semisynthetic fiber made from natural wood pulp, plus Lycra (a.k.a. spandex), which is obviously synthetic. The blend is very similar to the Tommy John underwear above, but the Lululemon has a much better fit.

Knix makes reliably good period underwear, and in ourguide to clothes that hide sweat, stylist Julia Gudova mentioned that the designs are meant to “trap moisture and fight odors.” That’s why period underwear is great for working out, even when I’m not menstruating. But this high-absorbency option prevents me from having to MacGyver a wad of toilet paper into my underwear if my disposable pad leaks while I’m on the treadmill (I’ve altogether given up on tampons, and menstrual cups still scare me). It also does an excellent job at keeping moisture away from my body, even if there is some slight VPL. It’s a give and take I’m willing to accept.

This Organic Basics thong was much better in terms of construction, as the seams are very flat and the Y-back cut felt the thinnest on this list, meaning minimal backside coverage. During my testing on runs, yoga, and Pilates, the mostly cotton fabric (91 percent!) was flexible, which made for a chafe-free experience, regardless of my bottoms, and it never felt overly tight or left deep indentations on my hips.

I’ve been testing the thong from Oregon-based brandBranwyn— it contains mostly merino wool — and it’s been my favorite because it has some stay-put compression but not enough to cause discomfort. The string part of the thong also doesn’t feel like too much pressure, which might be because the waistband is thicker at the back, so it’s anchoring the fabric from twisting or pulling. Made of a blend of 81 percent merino wool, 14 percent nylon, and 5 percent elastane, there is some slight texture to this Branwyn fabric, but I wouldn’t call it scratchy. It also seems to soften up with each machine washing. In terms of working out, I like that it appeared smooth under leggings despite the thin seaming at the leg openings.