Best Women's Workout Underwear of 2026

Pull on a pair of pale-gray leggings and you find out fast what a thong is made of. This one all but disappears: the knit is thin without going sheer, the cotton gusset is bonded flat at the edge rather than stitched, and the waistband lies down instead of printing a ridge across the seat. Of everything in this group, it's the pair we trust most under light-colored training clothes.

Staying put is the harder half of the job, and the fit here is among the strongest in the set. The waistband sits where you leave it, the leg openings don't saw at your hips, and the weak spot is stretch rather than slippage. Breathability is the other pleasant surprise: air moves through the knit well enough that a hot class doesn't leave you watching the clock.

What we didn't expect is how little there is to notice. Nothing digs in at the hip, nothing needs a discreet adjustment halfway through a set, and the pair stops being part of the conversation entirely — about the highest compliment underwear can earn.

Sizing is the one thing to decide deliberately, because the knit gives generously: if you're between sizes, go down. Five pairs in a pack covers a training week, and the pack sits toward the low end of what these cost, which matters for a garment that hits the wash after every session.

Not every workout calls for a thong, and this is the brief we keep for the ones that don't. It has a real leg opening and a real waistband, it doesn't pretend to be invisible, and in heat it's the coolest thing in this group — light and dry rather than close and clammy.

The fabric is synthetic rather than cotton, which is exactly what makes it work for sweat: it stays light instead of going damp and it comes out of the wash ready to go again. The trade is hand feel. This is a smooth, slightly slick knit, and if you want cotton softness against your skin, it will read as a compromise.

The cut is part of why it runs cool, too: a brief leaves more of the leg open than a bikini or a boyshort, which is what you want when the air is thick. It's also the one pick here listed in plus sizes, so the range goes wider than the seamless knits in this group.

The waistband is the whole reason to buy this one. It's cut high — well above the hip, level with the rise of high-waisted leggings — so there's no strip of fabric showing above your waistband and nothing sitting in the crease where a lower cut would fold over.

The rise does something flattering with the lower belly, which is why it keeps such good company with yoga pants. The knit stretches with you rather than compressing you, and the gusset is cotton-lined — the detail we look for in anything worn through an hour of sweating.

Sizing is worth settling before you order: the fit runs true for plenty of people and small for plenty of others, so check the chart rather than assuming your usual number. Order, try it over the leggings you'll wear it with, and keep the option to exchange.

Where it wins is under high-rise leggings, where a lower waistband leaves a gap and a brief leaves a line. It costs more per pair than our top pick, and if the high rise is the shape you actually wear, that's money well spent.

The thin, slick knits that vanish under leggings aren't built to move sweat anywhere, and a hard, hot session can leave you clammy in a way no cute print fixes. This brief is the pick here for that problem: it wicks, it dries quickly, and it stays breathable, which is the whole reason to spend more on something you sweat in.

The fabric is noticeably thinner and cooler than a cotton brief, and it holds its shape through repeated washing. The trade is feel — this is a smooth, slightly technical knit rather than a soft cottony one, and it's the sort of thing you appreciate for what it does or resent for what it isn't.

Fit is the catch. The sizing runs small and the waistband slips down on some builds, so order from the chart and go up if you're between. Get that right and it earns its place for hot yoga, summer running or a garage gym in August; for a gentle mat class, the thinner seamless styles here do the same job for a lot less.

Chafing starts where a brief's leg opening ends, and that's the gap a boyshort fills. These have enough leg to sit under loose shorts without peeking out, and the hems are flat and soft rather than elasticated, so they don't create a new rub line of their own.

Under a dress or a pair of running shorts, this is the shape we reach for first. The waistband is snug without digging, the knit stretches with you instead of binding, and there's no leg band tight enough to leave a mark — worth knowing if you've given up on anything with elastic in it.

The trade is warmth. Nylon against skin doesn't breathe the way the thin seamless knits here do, so a long, sweaty session under a dress can leave you clammy. For the walk to the studio, a summer skirt or a day of errands, it's an easy trade to make.

Six pairs is the number that matters here. That's a full training week without a mid-week wash, plus a spare living in the bottom of a gym bag, and enough redundancy that losing one to the laundry doesn't register as a loss.

The no-show claim holds up better than any other pair in this group. The knit is thin and smooth, the edges sit flat under a fitted legging, and there's nothing printing across the seat in a bright studio mirror. Softness is the other standout: silky against the skin, closer to a second skin than a garment.

The catch is hold. This is a relaxed knit rather than a compressive one, so if you want a pair that smooths you in, look at the high-waisted options here instead. For most training that's the right trade: a pair you forget about beats a pair you notice.

Between a thong and a brief there's a gap, and this cheeky cut fills it: enough coverage at the back to feel like underwear rather than floss, without the leg line of a full brief. The scalloped edge along the waist looks deliberate under a thin dress, which is more than most seamless pants can claim.

The waistband is where it gets unpredictable. On some builds it stays exactly where you put it through a session; on others it rolls within the hour and takes the smoothing effect with it. What's left is still a flattering, comfortable pair — just not the one to trust for a long run.

Sizing adds a second variable: the knit stretches generously, so a pair that's slightly snug out of the pack is the one that fits by the end of the day, and the numbers don't map neatly onto a standard size. Check the chart rather than reordering your usual.

Out of the pack, this is the pair that feels like it should cost more: silky, cool, almost weightless, with a smoothness you can feel in the hand. That feel is the reason we keep coming back to it, and it's also the reason it behaves the way it does.

Seamless under leggings, cotton-lined at the gusset, and cut as a bikini rather than a thong — a shape for anyone who wants more coverage than a thong without a brief's leg line. Under a soft legging or a jersey dress, nothing shows.

The grip is the trade. There's no elastic around the waist or the legs, which is why nothing pinches and why the pair can slide: on a long walk or a fast class, the waistband creeps and needs a discreet tug. The sizing is generous too, so check the chart before you commit.

For yoga, a walk, or a day of errands, that's a fair exchange for fabric this pleasant. For HIIT or a long run, take a pair with a defined waistband — the trade stops being worth it the moment you're sweating hard and hitching them up.