Our reviews are 100% organic. We do not accept payment for reviews or bundle with advertising budgets. In most cases, the brand is providing the product to our reviewers free of charge. Among many things to love about autumn running, we appreciate the daily thought process that goes into dressing for the conditions. Some days are perfect for standalone long sleeves, while others require some layering (and maybe gloves and a hat). We’re fortunate to have lots of options on the market for comfortable, durable, dependable mileage as the days turn colder. We’ve tested the following long sleeve tops that are designed to keep you warm and regulate your body temperature when moving through cold days ahead.
Ridge Merino Aspect Midweight Merino Wool Long Sleeve Shirt ($75)
Fabric composition: 84% Merino wool, 16% nylon. 180 g/m2*
(*Grams per square meter, a standard measurement for merino weight. Higher numbers mean thicker and heavier garments. Frequently these measurements are described as one of four categories: Ultralight (less than 150 g/m2), Lightweight (155 to 190 g/m2), Midweight (195 to 250 g/m2), and Heavyweight (greater than 250 g/m2), but there is some inconsistency among companies with these categories.)
Based in Mammoth Lakes, CA, Ridge develops much of their apparel with mountain adventure in mind—either ski/snowboard focused in winter, or trail running in warmer months. The Aspect collection is a great example of product versatility, featuring midlayers that are exceptionally comfortable and functional on their own, but layer very nicely under more technical outer layers when needed. This season’s version has construction updates improving its comfort and durability, utilizing a corespinning technique that wraps ultra-thin wool fibers around the nylon filaments, ensuring that wool is the only fiber resting against the skin. This shirt is cut long in the torso for easy tucking or increased coverage when worn alone, and the sleeves are built long with thumbholes that keep the shirt in place under gloves, or can function in place of gloves if conditions are more moderate. Raglan sleeves make this an easy fit under backpacks, and some color options offset the sleeves for some options aside from solid colors. We tested the long sleeve crew versions of this collection, but Aspect shirts are also offered in quarter-zip options for men and women, a balaclava hood option for men, and a high-neck top style for women. Available at www.ridgemerino.com.
Duckworth Vapor Hoody ($119)
Fabric composition: 50% polyester, 38% Montana merino wool, 12% modal wood pulp. 150 g/m2
Duckworth prides itself on having a 100% American sheep-to-shelf supply chain process, starting with wool sourced from a fourth-generation family ranch in the Northern Rockies of Montana. On the ranch, premium wool fleece is developed into eight different proprietary yarns that each have specific functions in mind. Vapor is Duckworth’s lightest merino fabric, made from a blend of merino wool, recycled bamboo fiber, and recycled polyester. Compared to other shirts in this test group, the Vapor wicks moisture away extremely quickly, and maintains its insulating capacity nicely when temperatures drop, but loses a bit of the odor resistance found with higher percentage merino options. It’s also the most versatile option for year-round wear. We’re particularly impressed with the Vapor Hoody, with a built in hood that provides extra warmth under a hat or on its own and rests comfortably against your back when not in use. A women’s equivalent of this model called the Vapor Tunnel Hood uses identical fabrics and construction, with the addition of thumb-hole sleeves. Vapor Hoodys are ideal for long hiking or backpacking days to keep sun off your neck without overheating. The overall Vapor collection is rather extensive, including shirts, tanks, underwear, and socks in addition to hoodies for men and women at www.duckworthco.com.
Icebreaker Merino 200 Oasis Long Sleeve Crewe Thermal Top ($105)
Fabric composition: 100% merino wool. 217 g/m2
One of the original players in the performance wool category, Icebreaker has seemingly perfected the comfort and functionality of garments for prolonged outdoor activity. The Oasis is actually listed as a hike-specific garment, but we prefer it over the company’s run-specific long sleeve top, because the fabric weight and merino content are significantly higher. Oasis shirts also come in a wide variety of color options, including solids and marbled cloud-dyed versions and fun seasonal graphics, so there’s an option for every mood. We really like the torso fit of this shirt for both men and women, which is slim enough to layer easily, but isn’t snug against your body like other Icebreaker models can be. The women’s style has a tapered midsection that has the same “slim but not tight” profile. Friction is further minimized by flatlock seams and gusseted underarms, and a drop tail hem allows for easy tucking. Icebreaker also makes Oasis leggings with the same fabric as the tops; all are available at www.icebreaker.com.
Ibex Journey Long Sleeve Crew ($95)
Fabric composition: 89% merino wool, 11% nylon. 150 g/m2
While much of the Ibex product lineup is 100% wool garments, the Journey collection incorporates a small percentage of nylon filaments to improve the overall durability and moisture transfer of the fabric without compromising the overall comfort, breathability, or odor resistance. Material construction features nylon-core spun merino for enhanced moisture wicking and durability. The Journey has an extremely soft and comfortable feel during and after exercise, and is ideal for mutli-day or multi-activity outings; these are probably our most frequently used tops when we’re not sure what the day will bring, as they’re well-built for pretty much anything. Journey tops are available in short sleeve options for men and women, with a handful of solid color options. The women’s versions of this shirt have been revised in the past year to have a relatively straight fit through the torso, rather than the tapered style of previous models—this accommodates a larger variety of users, and makes it consistent with the fit of the men’s version which also has a straight torso. Available at www.ibex.com.
Tracksmith Harrier Long Sleeve ($95)
Fabric composition: 89% merino wool, 11% nylon. 170 g/m2
A longtime staple of the Tracksmith lineup gets a significant update this season, thanks to the incorporation of 37.5 technology, which uses sustainable natural materials that are both durable and rapidly biodegradable. The resulting fabric has enhanced temperature regulating capability, and effectively discards moisture from your skin while it’s still in vapor form. Combined with a high percentage of merino wool, it leverages the inherent qualities of that yarn while supercharging the performance features. The resulting Harrier shirt is noticeably thinner and lighter than previous versions, and it has a roomier cut through the torso to accommodate more body shapes. The old Harrier used to have a somewhat restrictive fit for our male runners with muscular torsos, but this new version fits wonderfully comfortably. Likewise, the women’s version maintains a slight contour but is not restrictive at all. Aesthetically, subtle Tracksmith styling carries on, as completely clean solid-color schemes are interrupted only by a small logo patch at the front hem and embroidered rabbit on the left cuff. Harrier shirts are available in long and short sleeve versions at www.tracksmith.com.
Smartwool Men’s Active Long Sleeve Tech Tee ($95)
Fabric Composition: 53% merino wool, 47% tencel lyocell. Fabric weight not available
This midweight garment utilizes a nearly equal blend of merino wool and tencel lyocell, a wood-based fiber made from renewable raw material that adds softness and durability. Tencel is also naturally odor resistant, so you don’t compromise this aspect when decreasing the merino percentage, as can sometimes happen when merino is blended with nylon. Offset shoulder seams and a horizontal ventilation channel on the torso minimize chafing and help with thermoregulation. This shirt has a regular fit through the torso, resting loosely but easy to layer, with a very slight contour in the women’s version. There are discrepancies with the women’s version of this shirt, called the “Active Long Sleeve Tee” (without Tech) even though the fabric weights and composition are identical between the two. The women’s version has extended sleeves with thumb holes, while the men’s have regular cuffs. Women’s have six solid color options, while the three options for men all have offset color blocks. Available at www.smartwool.com.
Arms of Andes Alpaca Wool Long Sleeve Shirt ($85)
Fabric composition: 100% Royal Alpaca wool. 160 g/m2
While runners almost automatically understand wool to come from merino sheep, other sources are beginning to have a larger footprint in performance fabrics. Arms of Andes products are constructed from 100% royal alpaca wool, which outperforms merino wool in its warmth to weight ratio, natural softness, and moisture wicking ability. Their fabrics are ethically sourced in Peru, with the entire production chain staying in the country to minimize transport and improve quality oversight. Their long sleeve shirts are exceptionally comfortable, with a silky feel against the skin that is noticeably softer than merino products, but they also have a more prominent lanolin smell than most merino tops. Torso fit is close to the body but not clingy, and the women’s version is moderately contoured in the midsection. The natural stretchiness of alpaca fibers allows full range of motion. Alpaca fabric breathes well in heat and dries quickly, insulates very impressively when worn as a single layer, and we found these tops to be very durable over several consecutive uses. The shirts are available in solid color low-impact dye options for both men and women at www.armsofandes.com.
Norrona Femund PureUll Long Sleeve ($139)
Fabric composition: 100% merino wool. 180g/m2
When you’re dealing with Norwegian sporting goods companies, you often get weird names and products that are built for the harshest conditions—and both of those are present with Norrona, a fourth-generation family business creating equipment for all types of mountain adventures. They have an extensive range of apparel offerings using a variety of materials, but the Femund PureUll tops use 100% Responsible Wool Standard certified merino wool in a midweight thickness. The fabric provides strong insulation on its own with a stylish curved hemline, and layers easily for harsher weather with an asymmetric longer back cut for easy tucking. Fit through the torso is regular, with a mild contour in the women’s version, but we found the sizing for both genders to run slightly small, so size up if you are typically an in-betweener. These shirts are notable for contrasting color patterns in both men’s and women’s styles, most of which feature a large Viking graphic on the front as a reminder of where the shirts came from. Available at www.norrona.com.