Women's Gym Underwear: Sports Undies, Briefs & G-Strings

Lorna Jane gym underwear is the silent support you’ve been looking for - it goes under whatever you're rocking and just does its job. It sits flat, it stays put, and that's really the whole it. You can go for running briefs, sports undies or gym g-strings and thong underwear. They all can be found right here in our intimates activewear accessories range. Start your shop with one of our microfibre styles built with a cotton gusset. Briefs give you the most coverage through the seat and leg, while g-strings cut the fabric back, so there's less edge to show under close-fitting tights.

Pick what fits your style best or just based on how you like to work out. If it's coverage you're after, go brief. If it's visible lines you're worried about, a sport g-string will do more for you. Whatever you land on, you're getting 4-way stretch that moves when you do, moisture management that pulls sweat away from your skin, and a cotton gusset in the microfibre styles. They're just as good under your favourite tights as they are under jeans or work pants. Cotton where it counts.

Women's Sports Underwear for Training, Running and Pilates

Cotton soaks up sweat and hangs onto it. Not ideal when you're working hard. Our microfibre styles are knitted from LJ Soft Touch Microfibre, a 74% nylon and 26% elastane blend with moisture management that pulls sweat away from your skin. There's 4-way stretch in there too, so nothing pulls or digs when you drop into a squat or head out for a long one.

Then there's the cut. Some g-string styles are built seam free, or seamless, which takes out the seam that can press through a pair of tights. Not all of them are made that way, so check the product page if that's your deal breaker. Briefs go the other way, with more fabric across the seat. You trade a bit of visibility for coverage. Fair swap, depending on the day.

What Underwear Should You Wear Under Gym Tights?

Under gym tights, the flattest underwear shows least. Look for a fine microfibre or nylon-elastane knit rather than a thicker cotton knicker with a wide elastic edge, and check for a cotton gusset. G-strings remove the back and leg edges, so there's less to show through.

Colour does half the work too. Light grey and white leggings are the least forgiving things you'll own, and a colour close to your skin tone is generally less noticeable than black under pale fabric. Under darker or thicker gym pants you can wear whatever you like, so go brief and take the extra coverage. For Pilates and yoga, look for 4-way stretch so nothing pulls when you fold forward.

How to Choose Your Next Pair of Women’s Gym Undies

It mostly comes down to what's going over the top, and whether lines or coverage matter more to you on the day.

• Under light-coloured tights: go g-string. Less fabric, fewer edges, and pale leggings will find every edge you give them.
• Under bike shorts: a thong or g-string keeps the leg opening clear. A brief's leg edge can land near the hem and give you a second line across the thigh.
• For Pilates and reformer: you want 4-way stretch here, so nothing bunches at the hip when you're on your back or halfway through a lunge.
• For running: it's a coverage call. Briefs give you the seat and the top of the leg, a seam free g-string gives you less fabric and fewer edges under your tights. Plenty of people keep both in rotation.
• Off-duty and travel: these wear just as well under jeans as they do under leggings, so a pair you bought for training doesn't have to stay in the gym. Keep a spare in your gym bag.
• Colour choice: black, white, brown and cream cover the range. Under anything pale, go closer to your skin tone than black. Less contrast, less to see.

Looking after them is easy. Cold wash with like colours, skip the fabric softener and keep them out of the dryer. Use a wash bag too, because it stops stray fibres from the fluffier stuff in your load attaching themselves to technical fabrics. To keep your activewear looking its best, always check the individual garment's care label for specific washing instructions.

Frequently Asked Questions

Q: What's the difference between a sports brief and a sports g-string?
A: Coverage, basically. A brief covers the full seat with an elastic edge across the hip and leg, so you've got more fabric between you and your tights. A g-string cuts the back and leg edges out, which is why there's no edge to print through light or close-fitting leggings.

Q: Does gym underwear show through leggings?
A: It can, depending on the cut and the colour. Our microfibre styles are designed to avoid VPL, and a g-string takes the back edge out altogether. Colour matters just as much. Under white or light grey tights, something close to your skin tone will show less than black.

Q: What underwear should you wear for running?
A: Depends what you want out of them. Briefs if you'd rather have more coverage through the seat and leg, a sports g-string if you'd rather have fewer edges under your tights. Either way, a microfibre knit with moisture management pulls sweat away from your skin, where a cotton knicker just soaks it up and holds onto it.

Q: Can you wear sports underwear every day?
A: Yep. The same microfibre that works under gym tights is soft enough for a desk day, a long flight or jeans on the weekend. There's a cotton gusset in there too, so it's not synthetic all the way round.

Q: Is Lorna Jane underwear cotton?
A: Not all the way through, no. Our microfibre styles are a nylon and elastane knit with a cotton gusset, so the cotton sits at the gusset and the rest is synthetic. The elastane is what gives you the stretch. If you're after a full cotton pair, this range isn't it.