Underwear. We all wear it… Except for those who don’t, and that has its merits too. But the majority of us will be wearing something under our running shorts or tights. What you wear can make a big difference in the quality of your run.
But not all underwear is created equal. The best women’s underwear for running needs to be lightweight, breathable, non-chafing, and feel like a second skin. Chunky, thick underwear can weigh you down and cause chafing!
Our top choice is the Under Armour Pure Stretch Sheer Bikini bottom. It’s made of a comfortable mix of nylon and elastane, incorporates anti-odor technology, and has a breathable mesh design.
Keep reading to see our top 9. Maybe you’ll find the one that takes your performance from good to great!
Top 4 Best and Favorites
Under Armour Pure Stretch – Sheer Bikini
Reebok Seamless Hipster Briefs
Under Armour Pure Stretch Thong
Reebok High Waist Seamless Brief
1. Under Armour Pure Stretch – Sheer Bikini
Our top spot goes to Under Armour, who are well-versed in making attire that stands the test of every sport. This bikini-style underwear is soft and stretchable, featuring a 4-way stretch construction for extra comfort.
The nylon/elastane fabric is mesh-like and allows for great ventilation. It’s not necessarily moisture-wicking, but it does incorporate anti-odor technology that works against the growth of bacteria (that are usually caused by moisture).
The stretch technology and laser-cut edging means it’s super smooth and hard to see even under tights. Under Armour has also gone tagless with the Pure Stretch, adding an extra element of comfort.
The lightweight fabric feels like it’s hardly there when you’re on the run. They get another thumbs-up for being available in five sizes, from extra small to extra large.
Whatever your shape, size, or running habits, the Under Armour Pure Stretch Sheer Bikini should keep you supported, comfortable, and well-ventilated throughout your workout.
- Breathable mesh
- Features anti-odor technology
- 4-way stretch construction for comfort
- Available from extra small to extra large
- They run slightly small
2. Reebok Seamless Hipster Briefs
If you like a more hipster-style pair of underwear, these ones are our pick. Reebok is also known for making great sporting wear, and they’ve designed these to be as comfy as possible.
The waistband is elastic for easy on and off, and is also wide and seamless. You won’t find a tag there, either. They’ve omitted it for extra comfort and to reduce that annoying chafing.
Be careful, though – the waistband is seamless but the legs aren’t. You will most likely be able to see the seams under a pair of tights.
That being said, the material (nylon/spandex) is extremely soft against the skin and doesn’t ride up and cause discomfort. Just throw it in the washing machine with the rest of your clothes when you’re done running to have them clean and ready for the next day.
And as if all that wasn’t enough reason to get this underwear, it comes in a pack of 5, making it super cost-effective as well.
- Tagless waistband for comfort
- Seamless elastic waistband
- Design prevents them riding up
- Leg seams show through tights
3. Under Armour Pure Stretch Thong
Ladies, don’t knock a thong ‘til you’ve tried it. Think about it logically – it’s by far the most breathable piece of underwear on the planet, and there’s nowhere it can move once it’s on.
Here we have the top sporty thong that will see you through many a comfortable run. It’s made from a blend of nylon and elastane, with a nice stretch and skin-tight fit.
It features Under Armour’s antimicrobial technology to prevent odor, and is easy to throw in the washing machine when you get home. You’ll be clean and smelling fresh from start to finish.
The laser-cut edges offer a smoother under-tights look. It’s a vast difference from the usual seamed underwear, and won’t stand out at all.
With a size for every type of woman, a soft, stretchy feel, and a design that won’t move or ride up anywhere it shouldn’t, the Pure Stretch wins top spot for best running thong.
- Laser-cut, seam-free edge
- Soft, stretchy fabric
- Five sizing options to suit all women
- May lose its stretch if worn/washed regularly
Best Boy Shorts
4. Reebok High Waist Seamless Brief
If you’re a boy shorts kind of girl, you’ll want to try a pair of these. This three-in-one pack is affordable and offers more coverage than the others we’ve reviewed so far.
A high-waisted design comes to rest in the midsection for a supportive and flattering look and feel. Bear in mind that if you’re going to wear these, you’ll need high-waisted pants too!
The material is breathable and well-ventilated, so you don’t need to worry about the extra coverage causing overheating. Seamless-style constructions also means that there’ll be no lines, no rubbing, and no rolling up.
Another factor they do well on in that they’re good for machine washing and tumble drying.
Customers report that they run large, so think about trying a size down.
- Affordable 3-pack
- High waist for extra support
- Breathable fabric
- Seamless knitting style
- Sizing tends to run large
Best Merino Wool Bikini
5. Icebreaker Siren Bikini
In cold weather, everything from your beanie to your undies should be geared towards keeping you warm. Merino wool is the best of the best when it comes to warming fabric.
If you run in icy weather often, this bikini-style underwear should help keep you toasty in all the right places. It’s just as soft and stretchy as the others we’ve reviewed, with a Merino wool/nylon/elastane blend.
The beauty of Merino wool is that it helps regulate temperature. It brings an element of warmth in the cold, but not so much warmth that you begin to sweat more than your running should naturally cause.
Also, it’s naturally moisture-wicking and odor-resistant, keeping you dry and fresh for as long as possible.
- Temperature-regulating Merino wool
- Moisture-wicking and quick-drying
- Available for most sizes
- Seamed edges for a better grip and support
- The seams will show through tight pants
Top Merino Wool Thong
6. Icebreaker Siren Thong
If you live in a cold area and prefer thongs to other cuts, we present you the Siren – a Merino wool thong to keep you ventilated in the right way but as warm as possible too.
Just because there’s less material on a thong, doesn’t mean what is there doesn’t make a difference. This piece of underwear is crafted from 83% Merino wool, 12% nylon, and 5% Lycra.
It will do its bit to keep you warm but its big selling point is how soft and comfortable it is. This thong comes in five sizes and five colors – there’s something for every woman!
- Soft and stretchy
- Minimalist style
- Extremely moisture-wicking
- Five sizes and colors to choose from
- They’re slightly more pricey than others, but worth it for winter running
Best Merino Boy Shorts
7. Icebreaker Sprite Hot Pants
Icebreaker’s hot pants have great coverage and will keep your lower area warm and well-supported. Their combination of jersey core spun material reinforced with nylon fibers is strong and durable.
It also keeps the heat in without contributing to unnecessary sweating. The underwear is very breathable, allowing excess heat and moisture to escape. It dries quickly, too, keeping you comfortable and safe.
The seams are quite defined, so if you’re looking for something seamless these won’t be for you. But if you’re planning on running in winter and want something that regulates temperature and is soft and comfy at the same time, these are well worth a try.
- Wide, comfortable waistband
- Strong and durable
- Soft on the skin
- Three color choices
- The Merino price tag may not suit all runners
- Seams will show under skin-tight pants
Best Value Running Underwear
8. C9 Champion Sport Briefs
You can’t beat the value in this set of women’s running underwear. Four pairs of quality briefs for a very decent price, and they have many of the same features the more pricey ones do.
Customers do report that they often receive different colored items than what they ordered. But for the value, we believe you can’t be too picky!
This pair of underwear has some cotton in it for that silky soft feel, plus polyester and spandex for a stretchy, comfy fit and moisture-wicking properties.
There’ll be no visible seams with their flat-seam look, so you can wear this under anything, in any weather!
- 4-pack for great price
- Wicks away sweat
- Flat leg edges for no-seam look
- Doesn’t ride up
- The colors received may differ from what’s pictured
Top Thong 3-Pack
9. New Balance Breathe Thong
This minimalist thong almost feels like it’s not even there. Constructed from nylon and spandex, the material is thin and sprinkled with tiny vents to allow for good airflow.
With 3 in a pack, these are well worth their price tag. They’re tagless, seamless, and non-chafing, because they’re barely there!
Some runners may feel that the extremely thin design is not supportive enough. But if you like a lightweight pair of underwear, you should have no problems at all with these.
- Minimalist design
- 3-pack for added value
- Nylon/spandex blend
- Meshy fabric for airflow
- Some runners may not like the paper-thin feel
Not sure what to look for in the best women’s underwear for running? Here are some common questions that may help you make your decision.
What is Important in Women’s Sports Underwear?
Women’s sports underwear should, above all, be breathable and moisture-wicking. You don’t want to feel like you’re in a sauna. Your skin needs to be able to breathe, while not being bogged down with sweat.
The underwear should be super light. Thick, chunky underwear won’t be comfortable on the road and could chafe. Light, stretchy, soft underwear allows for a better range of movement and has much less chance of chafing.
Although it should be light and soft, the underwear should still have some padding for protection. Of course, it also needs to be designed in such a way that it’s not visible when you don your running shorts or tights.
Do I Need Underwear If My Shorts Have a Liner?
It’s generally accepted that if your shorts come with a built-in liner, you don’t need underwear. This is because the extra layer of clothing can cause chafing instead of reducing it.
But in the end, it comes down to personal preference. If you feel that the liner is enough, then there’s no need for you to wear an extra pair. But if you feel a little too naked without wearing proper underwear, then by all means, wear a pair.
There is no hard and fast rule with underwear! It’s all about what feels comfortable on you. Remember, discomfort will not just make for a miserable run, but it can affect your performance too. We suggest trying it both ways to see what works for you.
What Makes Running Underwear Better Than Normal?
Running underwear has been designed with the runner’s activity type in mind. There’s a lot of friction in that area when one is on a jog, and running underwear is specifically designed to minimize chafing.
It’s also crafted from material that is lightweight, breathable, and has a certain amount of moisture control. While everyday underwear is made with comfortable, soft materials, it’s more important for a pair of running underwear that the material doesn’t retain moisture, which can lead to bacterial infections.
You can run in normal underwear, of course. We’re not saying that you’ll definitely be overheating, chafing, and on your way to an infection – not at all!
But there’s a reason running underwear is so popular. It covers every potential issue that normal underwear could have, so you can run free without worrying at all.
What Should I Do If My Underwear Causes Chafing?
There are methods to reduce chafing, but the first thing we’d recommend is buying a pair of underwear that doesn’t cause chafing in the first place.
If you still need an extra measure, you can reduce pain from chafing by rubbing petroleum jelly or Body Glide on the problem spots before you head out. There are other anti-chafing creams out there as well.
What Underwear Should I Wear Under Tights?
If you’re looking for the best women’s underwear for running in tights, a thong is a good choice. It shows no seams, leaving you to be free and confident with no panty-line. There’s also a guarantee of a thong staying mostly in one spot, so the chance of chafing is quite a bit less.
If you’re uncomfortable with the thought of a thong, of course you can wear anything that’s comfortable for you. Be aware, though, that many pairs of underwear will most likely show lines through your tights, but if you don’t mind that then you’re free to wear whatever you like.