Best Wool Running Apparel of 2024

Wool clothing is an excellent option for running in warm and cool weather. Photo: iRunFar/Eszter Horanyi

As runners, we rarely avoid uncomfortable conditions, so we must have good clothing. For many of us, it means having the best wool running apparel in our closets. You can count on one material to keep you comfortable from wet to dry, cold to hot, and everything in between is wool — it is much more versatile than just being used for a cozy sweater. Companies make all sorts of running clothing from wool, including shirts, shorts, socks, neck gaiters, hats, and gloves.

We took an array of wool running items in different weather conditions, from heat to rain to snow to chilly mornings, to test their warmth, breathability, durability, and comfort. Our testing took place from the deserts of Utah to the mountains of Colorado to the home of merino wool in New Zealand. We tested in as many environmental conditions as possible.

This guide shares our favorite wool items to keep you moving in the best and worst conditions Mother Nature can create. For hot conditions, we turned to the Icebreaker ZoneKnit Merino Short Sleeve T-Shirt, and when we needed extra insulation in cold temperatures, we layered with the Smartwool Classic Thermal Merino Base Layer Crew. Below, you can read more about why iRunFar team members choose wool, our testing methodology, and frequently asked questions about wool.

Best Wool Running Apparel

• Best Wool Lightweight Long-Sleeve Shirt: Smartwool Classic All-Season Merino Base Layer Long-Sleeve
• Best Wool Midlayer Long-Sleeve Shirt: Smartwool Classic Thermal Merino Base Layer Crew
• Best Wool Short-Sleeve Shirt: Icebreaker ZoneKnit Merino Short Sleeve T-Shirt
• Best Wool Sports Bra: Ridge Merino Send-It Seamless Merino Wool Sports Bra
• Best Wool Socks: Darn Tough Stride Micro Crew Ultra-Lightweight Sock
• Best Thin Wool Socks: Smartwool Trail Run Crew Socks
• Best Wool Neck Gaiter: Buff Merino Lightweight Neckwear
• Best Wool Gloves: REI Co-op Merino Wool Liner Gloves 2.0
• Best Wool Beanie: Smartwool Active Beanie
• Best Wool Hat: Buff Pack Merino Fleece Cap

Wearing the Buff Merino Lightweight Neckwear and a wool shirt for a morning run in Colorado. Photo: iRunFar/Eszter Horanyi

Best Wool Lightweight Long-Sleeve Shirt: Smartwool Classic All-Season Merino Base Layer Long Sleeve ($90)

Formerly called the Merino 150 Base Layer, the Smartwool Classic All-Season Merino Base Layer is a versatile layer that many on the iRunFar team have considered the best merino wool base layer for running for years. This lightweight long-sleeve shirt works great as a standalone shirt, over a short-sleeve shirt for added warmth, or as a layering piece on cold days. The material is 88% merino wool fiber wrapped around a nylon core to increase durability while maintaining its softness and temperature- and moisture-regulating properties.

This top is available as a crew neck and quarter-zip, the latter of which was a top pick in our best cold-weather running gear guide. With multiple colors available, some of our team members wind up having multiple of this long-sleeve shirt in their closet. It’s a favorite top for our testers’ chilly runs, casual wear, and travel. We found it performs exceptionally well on cold and wet days as a layer under a vest or rain jacket to maintain dryness and warmth without overheating. It has also remained stink-free on some long running and hiking days.

Check out our in-depth Smartwool Classic All-Season Merino Base Layer Long Sleeve review.

Shop the Men's Smartwool Classic All-Season Merino Base Layer Long SleeveShop the Women's Smartwool Classic All-Season Merino Base Layer Long Sleeve

Best Wool Midlayer Long-Sleeve Shirt: Smartwool Classic Thermal Merino Base Layer Crew ($115)

The Smartwool Classic Thermal Merino Base Layer Crew, formerly called the Merino 250 Base Layer, is a 100% merino wool long-sleeve shirt designed to keep you toasty warm in cold conditions. Available in a crew neck and quarter-zip, Smartwool designed this thermal merino base layer for a slim fit for next-to-body warmth and ease of movement. The flatlock seams and shoulder panels reduce pressure points under a pack and prevent chafing.

This layer is not for people who run hot — it is significantly warmer than the Smartwool Classic All-Season Merino Base Layer we reviewed above. For those who need the added warmth, this versatile piece can be worn as an outer layer on its own or under a jacket or shell in wet or snowy weather. This base layer is also great as a travel or camping shirt in chilly weather as it is nice and soft and resists odor, though we recommend sizing up for more casual wear.

Shop the Men's Smartwool Classic Thermal Merino Base Layer CrewShop the Women's Smartwool Classic Thermal Merino Base Layer

Best Wool Short-Sleeve Shirt: Icebreaker ZoneKnit Merino Short Sleeve T-Shirt ($90)

The Icebreaker ZoneKnit Merino Short Sleeve T-Shirt stood out from other wool-blend shirts due to its fit, cut, and incredibly thin material that kept us cool during hot runs. The shirt features two wool knit types. It has a front mesh panel for increased ventilation and breathability. In some of the colorways, this mesh panel is a different color from the rest of the shirt, adding some style to it. The rest of the shirt includes the brand’s Cool-Lite fabric, which we’ve found to be one of the thinnest wool-blend options out there that is still durable. Made of 60% Lyocell and 40% merino wool, it’s an ideal blend for taking advantage of all the beneficial properties of wool while still staying stretchy and durable. We tested this shirt on plenty of overgrown trails and have yet to find an issue with its durability. The offset shoulder seams can help to reduce friction if you’re wearing a pack.

As with most wool products, we could wear this shirt multiple times without it picking up a stink, and it dried quickly after quick rinses in creeks.

Our female testers appreciated the fit of this shirt. While many other shirt options have a more boxy cut, this one was more form-fitting without being tight. It’s an excellent option for a base layer, as it’s easy to add additional layers on top for more warmth. Over the years, the colorways of this shirt have been a bit questionable for the women’s side with bright pinks and pastels, but it’s a flaw we’re willing to overlook for the shirt’s functionality.

Shop the Men's Icebreaker ZoneKnit Merino Short-Sleeve T-ShirtShop the Women's Icebreaker ZoneKnit Merino Short-Sleeve T-Shirt

Best Wool Sports Bra: Ridge Merino Send-It Seamless Merino Wool Sports Bra ($60)

The Ridge Merino Send-It Seamless Merino Wool Sports Bra uses a supportive, stretchy, and incredibly comfortable blend of materials. It features a mix of recycled nylon, merino wool, spandex, and polyester, and we found it easy to put on and take off, even when damp. Merino wool sits next to the skin, where its wicking properties can transfer moisture from your body to the outside of the bra, allowing it to evaporate. The nylon and spandex provide durability and stretchability. We’ve worn this bra multiple times between washes, providing a high level of support after many hours of wear.

This bra comes with two removable pads; even without them, it provides enough support for small to medium chests for running. It has a racerback cut, so there’s fairly minimal material to get sweaty. The bottom band is wide and has enough stretch to not feel overly tight or restrictive.

This bra didn’t get stinky even with a lower wool percentage in the blend than other items in this guide. We wore it happily for many days of fastpacking in a row and were never offended by its smell.

Best Wool Socks: Darn Tough Stride Micro Crew Ultra-Lightweight Sock ($20)

The Darn Tough Stride Micro Crew Ultra-Lightweight Sock is a fan favorite due to its low-bulk seamless fit. We found them to be the best wool running socks due to their merino wool blend material that keeps feet dry, comfortable, and blister-free mile after mile. Light arch support eliminates bunching and shifting as you move. These socks are reinforced at the heel and sides to improve durability and provide long-lasting comfort. With a six-inch cuff, this sock can protect your ankles from trailside vegetation and rocks.

Darn Tough is a family-owned company with a good track record for customer service. Their merino wool is 100% Responsible Wool Standard certified, and Darn Tough makes all of its socks in a mill in Vermont. If any durability problems arise, Darn Tough guarantees the socks for life — simply return the socks in question, and they will replace them under warranty.

These socks hold a place in our Best Running Socks guide for good reason.

Shop the Women's Darn Tough Stride Micro Crew Ultra-Lightweight SockShop the Men's Darn Tough Stride Micro Crew Ultra-Lightweight Sock

Best Thin Wool Socks:  Smartwool Trail Run Crew Sock ($28)

We turn to the Smartwool Trail Run Crew Sock when we want a thin, lightweight sock that won’t stink after a single sweaty run. The brand has seemingly made several iterations of this sock, calling it by different names and patterns. Still, its essence stays the same: it’s a thin sock with targeted cushioned areas on the heel and toe, exactly where you need it, and mesh areas to keep the rest of your foot cool.

The material blend is
53% merino wool, 14% nylon, 28% recycled nylon, 3% elastane, and 2% polyester. We found the socks to be stretchy and durable, though we eventually put holes around the ankles and Achilles area after extensive use.

Smartwool uses its Virtually Seamless toe design to remove the seams from areas prone to chafing. We found that these socks stay in place well, even when wet and in conditions where other socks might scrunch up. The crew height is perfect for protecting against trail debris, and a couple of fun patterns are generally available at any one time.

Best Wool Neck Gaiter: Buff Merino Lightweight Neckwear ($30)

The name Buff has become nearly synonymous with neck gaiters, so it’s no surprise our favorite neck gaiter is from the company that has kept many a runner’s neck warm for years. The Buff Merino Lightweight Neckwear is soft, wind resistant, semi-seamless, and 100% merino wool.

This light yet toasty layer is breathable and dries quickly. It uses wool’s natural ability to maintain warmth and help with temperature regulation even when damp. You can also use this neck gaiter as a hat, headband, face cover, and ear warmer. It scrunches up comfortably around the neck, yet we could pull it over our face and head when weather conditions deteriorated, and we needed a bit of extra warmth.

Best Wool Gloves: REI Co-op Merino Wool Liner Gloves 2.0 ($30)

The REI Co-op Merino Wool Liner Gloves 2.0 are a great lightweight pair of gloves for chilly runs. While the gloves are notves for extremely cold conditions, they work well for temperatures around freezing. They are more loose-fitting than many other options, making them easy to get on and off. A bit of spandex under the wrist provides stretch to keep the warmth and gloves secure on the hand. We loved these gloves as a standalone layer for cool mornings and a liner glove under a waterproof mitt for colder conditions. They feature 50% merino wool and 50% recycled polyester, so they retain all of the positive qualities of wool while still being stretchy and durable. During testing, these gloves came along on plenty of runs that involved scrambling, and they’ve held up to repeated contact with a sharp rock.

To help keep track of your gloves, a small clip will keep them together when not worn, and a small loop makes them easy to attach to a pack. While no gloves have truly impressed us with their touch-screen compatibility, these are relatively functional. We could get most phone functions to work without taking them off.

Best Wool Beanie: Smartwool Active Beanie ($25)

The Smartwool Active Beanie, formerly known as the Merino Sport 150 Beanie, is a sleek, lightweight beanie that provides extra warmth and protection on chilly runs without being itchy or bulky. The beanie’s combination of merino wool and polyester provides the temperature and moisture management of wool with some stretch and enough durability to make this hat last for many years of use.

We easily wore the beanie under a helmet and carried it in a pack or pocket as a just-in-case layer. We can’t say that the snug fit of this beanie made it exceptionally stylish for casual wear, but it was the right temperature for winter runs when we needed our heads covered. We could easily pull the hood of a mid-layer or jacket up over it without constricting our heads and necks.

Best Wool Hat: Buff Pack Merino Fleece Cap ($42)

If you want visor protection, lightweight warmth, and a built-in ear band, the Buff Pack Merino Fleece Cap is for you! Another pick in our best cold weather running gear guide, this hat has a unique design that checks many boxes for cold weather running. Say goodbye to an ear band or beanie piled on top of your brimmed hat — this hat does it all and stuffs away in your pocket when you don’t need it.

This lightweight, packable running hat has a baseball hat-style brim with a merino wool cap to combine face and eye protection from the sun with breathable warmth. You can pull down the earband for added warmth and coverage in colder conditions.

Melissa Beaury runs in a wool shirt on a cool desert morning. Photo: iRunFar/Eszter Horanyi

Why the iRunFar Team Chooses Wool for Running

Benefits of Wool Apparel for Running

Wool is a hugely popular material for running clothing. It’s known for having outstanding temperature- and moisture-regulating capabilities with its unique ability to transport moisture from your skin as a vapor instead of allowing it to turn into droplets. In addition, merino wool has several other features that make it a top choice among performance fabrics. Merino wool is inherently odor-resistant, making it a perfect choice for multiday adventures, fastpacking, travel, or just skipping a laundry day here and there. We could wear the Icebreaker ZoneKnit Merino Short Sleeve T-Shirt seemingly indefinitely without it picking up a smell.

It is also a great layering material, with many companies making items of varying weights to accommodate a range of temperature conditions. While technically marketed as a base layer, we frequently turned to the Smartwool Classic Thermal Merino Base Layer Crew as a mid-layer as well.

Wool also provides warmth when wet. While cotton and other materials hold on to water and can lead to a dangerous situation if they get wet when it’s cold outside, wool will continue to provide insulation even if you’ve sweat heavily or gotten caught out in a storm without a rain jacket.

Wool clothing is an excellent option for both warm- and cold-weather running. In the heat, wool will quickly wick moisture away from your skin and cool your body as the moisture evaporates. In the cold, wool provides a high level of insulation. Wool clothing can come in various thicknesses and is an excellent option for adding and subtracting layers as your run effort or the ambient temperature changes.

Moisture-Wicking Properties of Wool

Merino clothing works magic by trapping air between its fibers and reducing heat transfer to provide insulation. Because of its unique fiber properties, it can do this while transporting moisture away from your skin, helping to keep your body at a stable temperature. Unlike synthetic fibers that wick large moisture droplets away from your body, merino wool is porous and allows sweat to escape as a vapor before it turns into liquid droplets and soaks into a shirt, eliminating the wet, clammy, soaked-in-sweat feeling during and after a run. Wool can absorb a third of its weight in moisture, removing it from your skin and allowing it to evaporate before the material will even start to feel damp. The lightweight material of the Smartwool Classic All-Season Merino Base Layer will keep you warm and comfortable even if you start to sweat through it.

Advances in Wool Clothing

Modern-day wool clothing is nothing like the thick and itchy sweaters that many associate with Ugly Sweater Parties and the wool turtlenecks of the past. Most wool running apparel features merino wool, sourced from merino sheep adapted to live in hot and cold temperatures. Their fibers are made into lighter and softer pieces of clothing than other types of wool.

While most associate wool with cold-weather runs, many companies make shirts, sports bras, and underwear that work throughout a huge temperature range, including extreme heat. And for those winter runs when you need to stay warm, modern wool clothing, like the Smartwool Classic Thermal Merino Base Layer Crew, will keep you warm and dry when worn as a standalone layer or on top of or underneath something else.

Wool sports bras are an excellent option for running in any weather. Photo: iRunFar/Eszter Horanyi

Wool Blends

When choosing between the best merino wool running shirts, you need to consider the material blend of a piece of apparel. Clothing items geared toward warm weather activities will generally blend merino wool with another material, such as Tencel, nylon, or polyester, to make them lighter and more durable. Generally, wool fibers are wrapped around a nylon core so that the wool can still transfer moisture while the nylon provides some additional structure. Most lighter pieces of wool clothing will have lower percentages of wool than those designed to be insulating layers.

The lightweight Smartwool Classic All-Season Merino Base Layer, which also works in warmer temperatures, is made of 88% merino wool, while the Smartwool Classic Thermal Merino Base Layer Crew, which is a much warmer layer that we often use as an extra layer, is 100% merino wool. The higher the wool percentage in a blend, the more insulating the material will be.

Wool Sources

When we talk about wool for athletic performance clothing, we mean merino wool. Merino wool is a fiber grown by merino sheep, which are a rugged breed that evolved to withstand extreme temperatures in mountainous terrain. Merino sheep commonly come from Australia and New Zealand, where they can withstand temperatures from five to 90 degrees Fahrenheit with their warm yet lightweight and breathable fleece. This fleece creates a fine, lightweight fiber that is much softer and more breathable than traditional wool — so you won’t feel like you are running around in an itchy turtleneck.

Merino wool is a biodegradable and environmentally friendly material. All the products featured in this guide, including the Darn Tough Stride Micro Crew Ultra-Lightweight Sock, are made of wool sourced from humanely raised, non-mulesed sheep.

Morning running in the Buff Merino Lightweight Neckwear and a wool shirt. Photo: iRunFar/Eszter Horanyi

Why You Should Trust Us

The iRunFar team has been running in different types of clothing for decades. We’ve run in everything from cotton socks to shirts made from fully synthetic materials, and the material many of us keep coming back to is wool. Some of our testers, especially those who regularly go on multiday fastpacking trips or long road trips where laundry doesn’t get done regularly, will turn their noses up at anything not made of wool and have assembled running wardrobes consisting entirely of wool or wool-blend pieces of clothing.

Some items in this guide have been in our testers’ wardrobes for years, and some are new to everyone. We took a variety of wool pieces out in the deserts and mountains of the American West, the mountains of Oregon, and the varied and often wet terrain of New Zealand to test them for comfort, durability, breathability, and potentially, most importantly, the stink factor. Many items that made it into this guide have been used on several multiday outings to observe how to perform after multiple days of continuous wear. One of the biggest draws of wool clothing is its ability to ward off smells, and we wanted to make sure we could wear any items we recommend multiple times without them developing a stench.

Wool shirts are great for baselayers, extra layers for warmth, and casual wear. Photo: iRunFar/Eszter Horanyi

Frequently Asked Questions about Wool Apparel for Running

Is wool better than synthetic materials?

While wool and synthetic materials can both do an exceptional job wicking moisture from the skin, wool has the added benefit of not getting smelly as fast. We’ve all experienced the stench of a synthetic shirt after a hot run, and wool can keep the smell to a minimum. Wool apparel is an excellent option for road trips where you want to be able to re-wear the same shirt multiple times between laundry sessions, long travel days, and fastpacking trips where you don’t want to drive your partner out of the tent with the smell of your clothing.

Because of the unique moisture-wicking properties of wool, it stays dryer than many synthetic options. It removes moisture from the skin as a vapor instead of allowing it to form into droplets before being wicked away for evaporation. This inherently keeps the material dryer, and it’s rare to feel clammy in a wool shirt after a run. Wool is an excellent option for socks because of this as well. The best wool running socks, like the Darn Tough Stride Micro Crew Ultra-Lightweight Sock, can keep your feet dry and comfortable in both the heat and the cold. Wool can also provide insulation, even if it’s wet, which is critical if you’ve sweat through your clothing or run through a rain storm.

Is wool an environmentally friendly material?

Wool is a renewable and environmentally friendly material. Since it grows on sheep continuously and producers can harvest it regularly, it can be considered sustainable in many ways since it doesn’t directly use non-renewable materials.

Still, raising sheep on land has environmental impacts, including environmental degradation and animal waste. Animal rights also need to be considered. All the items in this guide are made from wool that comes from humanely raised, ethically sourced, non-mulesed sheep, so you can feel good about wearing them. Several items, like the REI Co-op Merino Wool Liner Gloves 2.0, also have recycled polyester in them.

Is wool running apparel durable?

If there is a significant downside to wool apparel, it is its durability. Wool tends to be less durable than synthetic materials, including polyester and nylon and can be prone to tears and rips that spread quickly.

Several factors can affect the durability of a piece of apparel. Wool clothing can come in various weights, and the thickness of the material affects its durability. Thicker and, thus, warmer merino clothing tends to be significantly more durable than thinner pieces.

To help with durability, many companies use wool blends instead of pure wool for thinner pieces of clothing. This can help reduce the chances of tears from abrasions or snags on the trail. Most of the gear in this guide, including the Icebreaker ZoneKnit Merino Short Sleeve T-Shirt, is made of a wool-blend material to increase its durability and stretchiness.

To extend the lifespan of wool clothing, it’s important to wash everything in cold water and let it dry on a line instead of putting it in a dryer. A properly cared-for piece of wool clothing can last a long time and is well worth the investment.

iRunFar’s Alli Miles goes on a sunrise run in the Icebreaker ZoneKnit Merino Short Sleeve T-Shirt. Photo: iRunFar/Eszter Horanyi

Is wool clothing good for hot-weather running?

Because of its unique moisture-wicking properties, wool is an excellent option for running in the heat. Wool transfers sweat from the skin before it can coalesce into droplets that get your shirt wet, helping keep you cool and dry in the heat. By using wool blends, companies can create extremely thin garments that still maintain all of the advantages of wool without being heavy or warm. The Icebreaker ZoneKnit Merino Short Sleeve T-Shirt is incredibly light and perfect for hot-weather outings.

Is wool clothing good for cold-weather running?

Wool is one of the original cold-weather clothing materials because of its insulating properties, and the Smartwool Classic Thermal Merino Base Layer Crew is an excellent option for when the temperatures drop.

Merino wool fibers are evolutionarily adapted to keep merino sheep warm in cold climates and provide an outstanding amount of insulation for their weight. Most wool garments designed for insulation feature pure wool instead of a blend. Wool can keep you warm even if it’s wet. This can be useful if you sweat a lot during a running effort or get caught in a rain or snowstorm. While other materials, namely cotton, can get extremely cold and thus dangerous when wet, you can trust wool to provide warmth under any conditions.

iRunFar’s Meghan Hicks wears a long-sleeve Smartwool shirt in Colorado’s San Juan Mountains. Photo: iRunFar/Eszter Horanyi

Can I layer with wool apparel?

Wool is an excellent option for nearly any layer of your running kit. As a base layer, wool can wick moisture from the skin and move it outwards so your skin doesn’t get clammy. Thicker wool shirts, like the Smartwool Classic All-Season Merino Base Layer, are an excellent option for adding insulation as it gets colder.

The percentage of wool in a piece of clothing will determine how insulating it is, with pure wool shirts being the warmest. Many shirts designed to function in warm weather as a standalone or base layer in the cold come from a wool blend. By blending wool with other materials, companies can make clothing more durable, stretchy, and able to dry quickly.

Many companies make both top and bottom wool baselayers, an excellent foundation for a running kit in cold weather. You can read more about base layer options in our Best Base Layers and Best Base Layers for Women guides.

Call for Comments

• Do you run in wool clothing? Which items or brands are your favorites?
• What weather or temperatures do you find wool the most comfortable?