Why isn’t wool top of mind as a year round fabric? Probably because we associate it with big fuzzy socks in the winter or those infamous holiday wool sweaters. But that’s just outdated thinking because wool is taking over the athletic apparel world.

A 4-year-long research collaboration has found that 100% Merino wool garments offer superior performance benefits during all seasons and for a wide-range of active outdoor activities.
Based on all the gear we’ve been testing year round, this doesn’t surprise us. But we know a lot of you are still skeptical, so let’s dig in and give you some top notch wool ideas to level up your training.
Why Wear Wool For Running
Woolmark and North Carolina State University call the concept “dynamic breathability.” Wool is able to adapt to changes in heat and temperature, cooling skin while you’re hard at work and then preserving heat when you stop.
Another plus is that wool is a natural fiber, unlike most synthetic blends that are used in other moisture-wicking, UPF, and cooling materials.
2007 study found that Merino wool is better than cotton and synthetics at keeping skin drier during physical activity. As we’ve talked about with summer running, getting the moisture off your skin helps with the body’s ability to cool itself, that’s why super hot AND humid runs can feel so tough.
Thermal Regulation and Moisture Management
A 2011 study in the Textile Research Journal found that Merino wool fibers absorb up to 30% of their weight in moisture , no matter the temperature.
Athletes everywhere are familiar with the chill that can set in as your skin begins to dry, and this research supports the idea that wool garments against the skin can help offset that effect. By pulling moisture away, you are going to less than bone chilling feeling we get in the winter after a hard workout.
Our Pick: Smartwool Merino Beanie
- It’s lightweight and can be worn year-round. In colder temps or when you need a helmet, it can be worn as a base layer.
- The rolled cuff makes it easy to cover your ears if you need to.
- It comes in a bunch of nice colors and patterns.
- You can machine wash and tumble dry.
Odor Resistance
Two separate studies, one in 2008 and another in 2012, found that Merino wool has natural antimicrobial properties that resist odor buildup better than polyester or cotton, and that it isn’t a welcoming environment for odor-causing bacteria, either.
This makes it great for travel or extra long days spent outdoors.
Our Pick: IBEX Springbok Sun Hoodie
It’s made of Merino wool and will do an excellent job of wicking moisture off your skin and releasing it as vapor whether the sun is hot or barely there, making it ideal for summer protection.
Here are some other reasons we love this sunshirt for runners:
- It has a UPF of 35+
- It comes in a large range of sizes and a few cool colors, and is made for women and men
- It’s made from Pro Tech Lite® fabric, and offers the versatility of both thumbholes and a hood.
Sustainability
While not directly related to performance on athletes, it is nice to know that we’re making good choices for the world around us, too.
Various Environmental Life Cycle Assessments (LCAs) assess wool as being biodegradable and renewable, though farming practices do play a role.
Our Pick: PAKA, in particular their wool undergarments.
PAKA emphasizes natural and recycled materials, employs compostable packaging and ethical production practices. They are recognized as a business for their positive impact on the environment and their commitment to a small carbon footprint.
Why we love their undergarments for running:
- Their specific blend of fabrics, including wool, dries quicker than many other types of wools.
- They’re naturally odor and microbe resistant.
- They are so thin and light they almost feel like you’re wearing nothing, and are perfect under light or heavier running gear.
Skeptical, You Aren’t Alone
Ultra runner Brad Dains was skeptical when someone recommended Merino wool, but then was pleasantly surprised by what happened when he tried it out:
“The race began around 45F with humidity in the 80% range.
For the first hour of the race I was comfortable. Not too warm. Not too cold.
Then the rain started and it rained…and rained…and rained for nearly 10 hours.
I was soaking wet and everything I had read about merino was coming to fruition. When I should have been cold in the soaking wet, I was actually quite comfortable…
For the whole 28 hours that this race took….another story for another time….I wore two different tops (and a Salomon jacket for the overnight section) for the whole event and both merino wool blends.
Aside from a short 2 hour section where the winds picked up a little bit with the rain (where I actually did throw a garbage bag on) I was incredibly comfortable for the entire race.”
Our team has had a lot of the same experiences, which is why you see so many different recommendations from best sun shirts, to best running socks to best winter gear including wool options!
Drawbacks to Wool Running Gear
There are many benefits to wearing Merino wool during outdoor exercise, but no fabric is perfect!
Here are a few cons to consider before you run out and break the bank:
- Cost: It is more expensive than synthetic or cotton options
- Durability: The material is thin and soft, and pills easily, meaning these items will require extra care to get the most wear out of them. They also tend to stretch over time.
- Longer Drying Times: Because it can soak up so much water without feeling wet, Merino wool takes longer to dry than its synthetic counterparts, which are designed to dry quickly.
- Fit Issues: If you enjoy or need compression wear or more support, these garments are likely to feel loose to you.
Here’s a video that explains the research with visuals:
Despite the few downsides, I can only imagine that this new research will further encourage manufacturers like Smartwool, Paka, and IBEX to continue coming out with excellent products for everyone to fall in love with.
The science is definitely showing up to support the idea of Merino wool being a go-to for performance activewear.
Merino wool seems to be having a moment.
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