
Best underwear for reformer Pilates (from people who actually do it)
Reformer Pilates is uniquely brutal on underwear, and nobody warns you. It's not the sweat — a reformer class barely breaks one. It's the positions. You spend half the class lying down, bridging, or folded in half with your hips higher than your head. Underwear that behaves perfectly while you're standing gives up entirely somewhere around the third footwork series.
Why the reformer finds every flaw
Three things happen on a reformer that don't happen at a desk:
- You're horizontal, then inverted, then horizontal again. Gravity keeps changing its mind. Seams and waistbands that sit quietly when you're upright start migrating the moment your hips tilt. That's the mid-class adjustment shuffle — you know the one, disguised as fixing your leggings.
- The carriage is behind you. Half the room has a direct view of your leggings in extension. If there's a line, it's presenting. If the fabric's thin, everyone knows what you've got on underneath.
- Friction, in slow motion. Reformer work is slow and loaded. A seam that rubs a little at walking pace rubs a lot through fifty controlled reps of feet-in-straps.

What actually works
Four construction details do the heavy lifting. This is what to look for on any label, ours or not:
1. Bonded edges, not stitched elastic
Stitched elastic is the thing that digs when you bridge. Bonded (glued, flat) edges have nothing to press into you, so there's no mark on your hip when you change afterwards, and nothing to migrate when your hips tilt.
2. An actual seamless back
"Seamless" on the packet often means "fewer seams". Check the back panel — that's the part on display in extension. If it's one uninterrupted piece, no line.
3. A cut that stays put upside down
A thong or G-string sounds counterintuitive for exercise until you realise there's simply less fabric to bunch. The catch: it has to be cut for movement, with a waistband that anchors on your hips rather than your waist, or it creeps. If you've only tried lace ones, that's the version that rides. A movement-cut seamless G is a different garment.
4. A cotton-lined gusset
You're in close contact with a shared carriage for 50 minutes. Breathable cotton where it matters, with a technical body everywhere else, is the sensible split — the nylon wicks, the cotton breathes.
The honest bit
Some women do reformer in nothing at all under their leggings, and if that works for you, genuinely, carry on. The case for a good pair anyway: hygiene on shared equipment, one less laundry decision about the leggings themselves, and — the real reason — leggings alone still show a line at the waistband if they're mid-rise. The right pair underneath is invisible and deals with all three.
Where ours fits
We make exactly one style — the Gym G — and it was built for this list before we'd ever heard of it: bonded edges, seamless back, movement cut, cotton-lined gusset. It's $32 a pair, or $21.90 a pair in the 10-pack if a week of reformer classes describes your life. Most of our customers came for the studio and stayed because it turned out to be the pair they reached for on the other five days too.
Further reading
- What to wear under leggings: the no-VPL guide
- The right underwear for hot Pilates (different problem — that one IS about sweat)
- The complete guide to underwear that disappears


