By Michael Lanza
Let’s admit it: We don’t always take our base layers as seriously and we do our outerwear and insulation—or packs, tents, boots and other gear, for that matter. But this under-appreciated first stage in a layering system for the outdoors really sets the table for how comfortable you’ll be. Base layers that don’t perform well probably won’t kill you, but misery isn’t a good companion. This is what we wear against our skin. It matters.
After much testing from the trails to the mountains to the gym year-round, the long-sleeve tops, T-shirts, shorts, underwear, and socks reviewed here are the best I’ve found for dayhiking, backpacking, trail running, climbing, and training. And over the course of a quarter-century of testing and reviewing gear, as the lead gear reviewer for Backpacker magazine for 10 years, and many years for this blog, I’ve learned how to distinguish the mediocre from the excellent.
Light- and medium-weight T-shirts and long-sleeve tops are the most versatile because you can layer them in a wider range of temperatures to keep you drier and cooler, but fabrics and design features of tops and shorts also affect their temperature range and the activities for which they’re comfortable.
Please leave any comments or questions about my picks for best base layers in the comments section at the bottom of this story. I try to respond to all comments. And you can support my work on this blog, at no cost to you, by making purchases through the affiliate links below—where you’ll also often find the best prices. Thank you for doing that.
What You Need to Know About Synthetic Versus Wool
We all know that synthetic fabrics wick moisture and dry quickly, while wool keeps you warm even once it’s wet. My experience with dozens of base layers is that both types keep getting better. Modern synthetics are getting lighter and more efficient at moving moisture. I wear lightweight synthetic base layers for high-intensity activities in warm temperatures, and midweight synthetics for moderate-intensity activities in cool temps. But synthetics can get sweat-soaked (leaving you cold on cool days) and stinky after many days of wearing and multiple washings.
Wool—which today often means Merino wool—keeps getting softer and more comfortable, and I find myself wearing it more often, for virtually any activity, in a wider range of conditions than I ever did before. It breathes as well as any fabric; doesn’t dry as quickly as synthetics, but keeps you warm, anyway; and won’t develop odors. But the lightest Merino wool tops aren’t always as durable as synthetics.
Top Pick T-Shirt
Patagonia Capilene Cool Trail Shirt
$39, 4.5 oz. (men’s medium)
Sizes: men’s and women’s XS-XXL
From local trail runs of up to 20 miles in temps from 60 to 80 degrees and cool, wet days of camping and rock climbing, to a five-day, 78-mile backpacking trip on the Wonderland Trail around Mount Rainier and four days of variable weather on Nevada’s Ruby Crest Trail and five cool, sometimes very windy and snowy days trekking in June through Spain’s Picos de Europa Mountains, this t-shirt has become my go-to for countless days and virtually any kind of activity.
I lived in this T-shirt—waking and sleeping hours—under other layers and sometimes alone for three straight days in the Picos. It has the soft, comfortable feel and fit of your favorite cotton tee. And the Polygiene permanent odor control treatment has prevented it from getting a perma-stink after many workouts, hikes, runs, and launderings.
Its polyester fabric wicks moisture and dries remarkably quickly: Wearing it alone or under other layers, I’d sweat through it while hiking or running uphill, feel an icy chill of the wind blowing through wet fabric against my skin; and next thing I knew, within minutes after reducing my exertion level, I’d notice the T-shirt was dry again. It happened several times a day.
BUY IT NOW You can support my work on this blog, at no cost to you, by clicking either of these affiliate links to purchase a men’s or women’s Patagonia Capilene Cool Trail Shirt or other Capilene Cool Trail tops at backcountry.com or patagonia.com.
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Most Versatile T-Shirt
The North Face Hyperlayer FD Short-Sleeve Crew
$35, 6 oz. (men’s medium)
Sizes: men’s S-XXL, women’s XS-XXL
For five days of backpacking through hot spring days in the Grand Canyon (lead photo at top of story) and six days backpacking in variable temps and weather in Utah’s High Uintas Wilderness—plus innumerable dayhikes, trail runs, and gym workouts—the rugged Hyperlayer FD Short-Sleeve Crew T-shirt almost never left my back. The Polyester with FlashDry technology in this T-shirt dries fairly quickly while wearing it—especially for a T-shirt that’s a little beefier and more durable than lighter tees, making it better suited than others to wearing under pack straps day after day. After a full day of hiking in it, I could rinse it in a creek or the Colorado River to get the sweat stains and much of the stink out of it, pull it back on damp for the cooling effect, and it would be dry and almost fresh minutes later.
Seams are positioned forward of the shoulders and bonded for added durability and comfort under backpack straps. While the fabric feels more slickly synthetic than cottony soft, it’s comfortable enough against the skin, and has a loose, standard fit, that I regularly wear it for gym workouts, too. The UPF 30 sun protection kept my skin from getting baked in the Grand Canyon.
BUY IT NOW You can support my work on this blog, at no cost to you, by clicking this affiliate link to purchase a men’s or women’s The North Face Hyperlayer FD Short-Sleeve Crew backcountry.com.
For high-speed workouts in damp weather, get a breathable, ultralight wind shell. See my reviews of the best ones.
Adidas Agravic Parley Tee
$40, 3 oz. (men’s medium)
Sizes: men’s S-XXL, women’s M-XL
When you need the lightest, fastest-drying T-shirt for hot days, especially for trail runs or rides or dayhikes, this featherweight is the one. From sun-baked trail runs to the sweatiest gym workouts, the Adidas Agravic Parley Tee kept me cooler than a heavier t-shirt would and dried really fast, thanks to Adidas Climalite treatment for superior moisture management.
The Agravic Parley Tee’s production minimized environmental impact before it begins minimizing how wet you are in it. Recycled polyester, made using yarn manufactured from recycled plastic waste retrieved from beaches and coastal communities before it washes into the ocean, comprises 80 percent of the Parley. The lightweight material isn’t as soft as some others reviewed here; that and the loose fit make it best suited to aerobic activities like running and gym workouts, rather than activities that involve wearing a pack.
BUY IT NOW You can support my work on this blog, at no cost to you, by clicking this affiliate link to purchase the men’s or women’s Adidas Agravic Parley Tee at backcountry.com.
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Most Versatile Long-Sleeve
Patagonia Capilene Midweight Zip-Neck
$69, 7.5 oz. (men’s medium)
Sizes: men’s XS-XXL, women’s XXS-XL
If the ultimate proof of any garment’s value is how often and in what range of conditions you wear it, the Patagonia Capilene Midweight Zip-Neck has more than covered its price. I’ve worn it on innumerable days in a wide variety of conditions, from trekking through strong, cold wind in rain and falling snow in northern Spain’s Picos de Europa Mountains, to cool evenings and mornings while backpacking in the Grand Canyon and rock climbing and camping at Idaho’s City of Rocks National Reserve. Whether hiking, climbing, on a winter trail run, or backcountry or resort skiing, I increasingly find myself grabbing it from a drawer full of tops for a variety of activities in all seasons.
Comfort is excellent thanks to flatlock seams and shoulder construction that allows full mobility without causing the top to hike up. The fabric’s smooth face slips easily into fleece jacket sleeves. Thumb loops hold the sleeves over your hands. The Polygiene odor control has prevented it from getting stinky through many sweaty outings and launderings. All in all, you get a four-season, midweight top with Patagonia quality.
BUY IT NOW You can support my work on this blog, at no cost to you, when you click either of these affiliate links to purchase the men’s or women’s Patagonia Capilene Midweight Zip-Neck at backcountry.com or patagonia.com.
Plan your next great backpacking adventure in Yosemite and other flagship parks using my expert e-guides.
Favorite Sun Shirt
Mountain Hardwear Crater Lake Long-Sleeve Hoody
$65 (women’s $60), 5.5 oz. (men’s medium)
Sizes: men’s S-XXL, women’s XS-XL
Wearing it under a hot sun from rock climbing and hiking with heavy climbing packs in Idaho’s Sawtooth Mountains and City of Rocks National Reserve to backpacking Utah’s High Uintas Wilderness, Nevada’s Ruby Crest Trail, and the 96-mile Wind River High Route, the Crater Lake Hoody became my go-to sun shirt and kept me cool and comfortable even with the hood up much of the time.
Among the lightest hoody sun shirts, its polyester and elastane fabric feels smooth and soft against skin and wicks moisture quickly: Hiking with a pack loaded with climbing gear under a hot sun, I sweated but the shirt never got very wet. With very stretchy fabric, this shirt fits closely and yet easily pulls over a short-sleeve base layer, and its deep hood stays put even in strong wind—and helps this sun shirt protect me from annoying mosquitoes, as it did on a buggy, six-day backpacking trip in Utah’s High Uintas Wilderness. A UPF 50+ rating translates to maximum sun protection—impressive for this light fabric.
BUY IT NOW You can support my work on this blog, at no cost to you, by clicking this affiliate link to purchase a men’s or women’s Mountain Hardwear Crater Lake Long-Sleeve Hoody at backcountry.com.
See my review of “The Best Sun Shirts.”
Softest Wool Top
Smartwool Merino 150 Baselayer Long Sleeve
$80, 7 oz. (men’s medium)
Sizes: men’s S-XXL, women’s XS-XL
Merino wool is soft, very breathable, warm even when wet, and doesn’t get smelly. But the lightest Merino shirts can wear thin and suffer small tears sooner than synthetic fabrics of comparable weight. With the Merino 150, Smartwool wrapped Merino fibers around a nylon core to make the fabric more durable, without compromising the soft-against-skin feel of Merino. The result is a top you can wear as a base or second layer in moderate temperatures, or layer over it in cold temps, without worrying about pack straps shredding it prematurely.
The flatlock, offset shoulder and side seams mean no bothersome seams directly under pack straps. And the super-soft Merino 150 not only feels wonderful against skin, it’s light enough to dry quickly: On one three-hour, mountain bike ride on a mostly sunny day in the 50s Fahrenheit with light winds, I wore this top while pedaling two hours up more than 2,000 vertical feet—getting quite wet with perspiration. I pulled on an ultralight, breathable wind shell over it for the long ride downhill, and this base layer was almost completely dry when I got home.
BUY IT NOW You can support my work on this blog, at no cost to you, by clicking this affiliate link to purchase a men’s or women’s Smartwool Merino 150 Baselayer Long Sleeve at backcountry.com .
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Versatile, Four-Season Top
Patagonia Men’s R1 Pullover Hoody
$159, 10 oz. (men’s medium)
Sizes: men’s XXS-XXL
Patagonia touts this pullover for climbing and skiing—for which it’s certainly ideal—but I find myself constantly wearing it year-round, in a range of temps. Besides days of backcountry skiing, I lived in this pullover—waking and sleeping hours—for three cool, wet days of camping and rock climbing at Idaho’s City of Rocks National Reserve, and it was the only insulation piece I needed for a six-day backpacking trip in May in the Grand Canyon.
The versatility lies in the Polartec Power Grid fabrics, used exclusively by Patagonia. They have outstanding stretch and breathability and excellent warmth for their weight, making this top versatile as a layering or stand-alone piece in temps ranging from the 50s Fahrenheit to as far below freezing as you can bear. A midweight fabric is used on the front, back, and sleeves, while a slightly lighter, more breathable grid fabric comprises the hood, sides, armpits, and girding the waist. The pullover’s close fit has space for layering a lightweight T-shirt or long-sleeve underneath, or wearing alone and under other layers, and the extended length stays tucked inside a pack belt or climbing harness.
I frequently pulled the close-fitting hood over my head and felt an immediate and noticeable difference in warmth; but I also found it easy to tuck the hood under the collar, out of the way (with little bulk, it doesn’t interfere with another hood in a layering system); it also fits smoothly under any helmet. The front zipper plunges nearly to the belly button for superior venting and zips up to let the balaclava-style hood cover your nose when desired. The elasticized cuffs, with thumbholes for wearing the sleeves up to your fingers, have good stretch to both seal out cold air and slide the sleeves up to the elbows. The zippered chest pocket has enough space for a wool hat or light gloves, and is mesh-lined, so you can put a damp hat or gloves in there to quickly dry from body heat. Polygiene treatment controls odors.
BUY IT NOW You can support my work on this blog, at no cost to you, by clicking any of these affiliate links to purchase a Patagonia Men’s R1 Pullover Hoody at backcountry.com or patagonia.com, a women’s R1 Pullover at backcountry.com or patagonia.com, or a women’s R1 Crew at backcountry.com or patagonia.com.
Got an all-time favorite campsite? See “Tent Flap With a View: 25 Favorite Backcountry Campsites.”
Soft, Warm, Breathable Yak Wool
Kora Shola 230 Crew Base Layer
$145, 8.5 oz. (men’s medium)
Sizes: men’s S-XXL, women’s XS-XL
The soft yak wool of the Shola 230 will redraw your mental image of what wool feels like, while expanding your expectations of this natural fabric’s wide temperature-comfort range. I wore this top—both alone and over a light, short-sleeve base layer—during chilly mornings on back-to-back, 21-mile and 23.5-mile, rim-to-rim dayhikes across the Grand Canyon in mid-October, in temps from the high 30s to the low 50s (before I pulled it off); on cool October mornings dayhiking the Observation Point Trail and The Narrows in Zion National Park; and while Nordic skate-skiing in temps in the 20s in Idaho.
It’s warm for its weight, possibly partly due to the weave’s density. Kora says this fabric—made from Hima-Layer Original 230 fabric, using yak wool harvested by nomad families on the Qinghai Tibet plateau in the Himalayan Mountains—is 40 percent warmer and 66 percent more breathable than Merino wool. Flat-locked seams are positioned off the shoulder to avoid pack straps, and the close fit helps move moisture off skin without inhibiting freedom of movement. This midweight top is worth its price for its versatility from the mountains in summer to any activity from fall through spring.
BUY IT NOW You can support my work on this blog when you click either of these links to purchase the men’s Kora Shola 230 Crew Base Layer at kora.net, or the women’s Kora Shola 230 Crew Base Layer at kora.net.
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Lightest, Best Wicking Long-Sleeve
Patagonia Long-Sleeved Capilene Cool Lightweight Shirt
$55, 3.5 oz. (men’s medium)
Sizes: men’s XS-XXL, women’s XXS-XL
On numerous, long trail runs in wide-ranging temperatures and weather in the Boise Foothills, this wafer-thin long-sleeve was stellar either alone in mild conditions or as a base layer under an ultralight shell or warmer long-sleeve top in wind or cooler temps. Even on runs where I perspired heavily, the Capilene’s wicking ability was never overwhelmed—it kept moving moisture as long as my body was producing heat, so it was never more than damp.
Thumb loops kept my hands partly covered when needed, or I could easily push the sleeves up over my elbows when temps rose. Treated for odor control, this top hasn’t gotten stinky after countless days on the trail. With UPF 35 sun protection and Fair Trade Certified, this crew top is better for training and aerobic activities like trail running than for wearing with a pack, which might wear out this light fabric quickly.
BUY IT NOW You can support my work on this blog, at no cost to you, by clicking any of these affiliate links to purchase a men’s or women’s Patagonia Long-Sleeved Capilene Cool Lightweight Shirt at backcountry.com or patagonia.com, or a men’s or women’s Patagonia short-sleeve Cool Lightweight Shirt ($45) at backcountry.com or patagonia.com.
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Flylow Hardcastle Short
$60, 7 oz. (men’s small)
Sizes: men’s XS-XXL
When you need cool, comfortable shorts that can handle hard use in hot-weather activities, the Hardcastle Short shines like the sun. These shorts have become a favorite of mine for dayhiking and backpacking because they strike a nice balance between having pockets and durability without feeling too heavy or warm. They stayed dry, gave me complete freedom of motion, and never felt too warm as I sweated through hot days on two spring backpacking trips of four days and six days in the Grand Canyon (lead photo at top of story). They also look no worse for the wear, holding up better than many lighter shorts.
The stretchy, 89% polyester, 11% spandex Intuitive IQ fabric is tough but dries quickly enough to never feel wet—partly thanks to the loose, airy fit—and the no-fuss elasticized waistband feels good under a pack’s hipbelt and holds its shape no matter how wet. Unlike lighter shorts, the Hardcastle has four mesh pockets; only one rear pocket is zippered (the other rear pocket has a snap), but the two in front are deep enough to not easily lose anything small inside them. The 40+ UPF rating and 10-inch inseam deliver good sun protection. Unlike most of the shorts reviewed here, though, this pair does not have an internal liner brief. These shorts are a solid, comfortable choice for everything from trail running and SUP-ing to backpacking and ultra-hiking.
BUY IT NOW You can support my work on this blog, at no cost to you, by clicking this link to purchase the Flylow Hardcastle Shorts at backcountry.com.
Most Versatile Shorts
Patagonia Nine Trails Shorts
$65, 7 oz. (men’s small)
Sizes: men’s and women’s XS-XXL
These shorts, with an eight-inch inseam (four inches in the women’s shorts), became another favorite for trail runs and warm-weather dayhikes (as well as gym sessions) because the lightweight, 75-denier recycled polyester-spandex fabric breathes well, but is also durable enough for rugged trail use, and has a DWR treatment to repel light rain.
The stretchy, odor-resistant, built-in boxer-brief liner, made with a microdenier polyester, dries quickly, but anyone with big thighs or glutes will find the liner’s fit snug or want to size up. The two zippered hand pockets are mesh lined for ventilation and as large as my open hand; the one zippered rear pocket is big enough for a small phone. A drawstring helps secure the waist, but I rarely needed it thanks to the good elasticity in the waistband. Grab these when you need shorts that are cool and dry fast, but also have the convenience of pockets and some durability and water resistance for longer trail runs or hikes.
BUY IT NOW You can support my work on this blog, at no cost to you, by clicking either of these affiliate links to purchase the men’s or women’s Patagonia Nine Trails Shorts at backcountry.com or patagonia.com.
Choosing the best hiking socks can, admittedly, sometimes feel like choosing between ping-pong balls—they all kind of look alike. But I’ve hiked and backpacked in numerous models from just about every brand out there, and I’ve found a few that stand out for the qualities I like in socks: comfort against my skin; fast-wicking and quick-drying, to help my feet stay dry in footwear, even after many hours; a bit of padding at the heel and toes; and fabric that holds its shape and doesn’t get stinky, so I can wear them on consecutive days without washing.
A few models from Darn Tough stood out for all of those reasons—plus, as the name implies, these are durable socks. The Light Hiker Micro Crew Light Cushion ($21, 2 oz.) proved ideal for much of the dayhiking and backpacking I do, because they’re comfortable in the normal range of temps encountered in the mountains from late spring through mid-autumn or in milder climes like the Southwest in spring and fall, and are tall enough for any boots without being higher (and warmer) than I prefer.
The Hiker Micro Crew Cushion Sock ($23, 2.5 oz.) is similar but slightly taller and warmer, so it works nicely for me on backpacking trips when temps are getting cooler, like September in the mountains.
When I’m heading out backpacking in chillier temps and possibly wetter or even snowy weather, wearing sturdier boots, I’m all in with the Darn Tough Hiker Boot Sock Full Cushion ($26, 3.5 oz.)—which has held up well in hard use and keeps my feet warm without them getting too sweaty (although it’s too warm for relatively mild trips).
BUY IT NOW You can support my work on this blog, at no cost to you, by clicking any of these affiliate links to purchase these socks:
The men’s Darn Tough Light Hiker Micro Crew Light Cushion Sock at darntough.com, or the women’s Light Hiker Micro Crew Light Cushion Sock at darntough.com, or the men’s, women’s, or junior at backcountry.com or moosejaw.com.
The men’s Darn Tough Hiker Boot Sock Full Cushion at backcountry.com or darntough.com, or the women’s Hiker Boot Sock Full Cushion at backcountry.com or darntough.com, or the men’s or women’s at moosejaw.com.
For similar reasons, I’ve become a fan of socks from Farm to Feet. The Farm to Feet Damascus Lightweight Technical ¼ Crew ($20, 2 oz.) has become a staple sock I wear for dayhikes of any length and lightweight backpacking in relatively light boots or low-cut shoes. These light, airy socks reach just above the ankle—high enough for mid-cut boots—and kept my feet dry and hold up to multiple days of use.
The Farm to Feet Max Patch Lightweight Technical ¾ Crew ($22.50, 2 oz.) is essentially the Lightweight Technical ¼ Crew extended to reach the calf, for wearing with sturdier boots, but they’re still light and breathable enough that feet don’t easily overheat on warm days. The Farm to Feet Damascus Lightweight Technical Low ($18, 1.5 oz.) are simply a no-show version of the others that I find ideal for trail running.
BUY IT NOW You can support my work on this blog, at no cost to you, by clicking any of these affiliate links to purchase the Farm to Feet Max Patch Lightweight Technical ¾ Crew at rei.com. You can also find various Farm to Feet socks at backcountry.com.
See all Farm to Feet socks at farmtofeet.com.
Most Comfortable Underwear
MyPakage Pro Series Boxer-Brief
$30, 3 oz. (small)
Saxx Quest 2.0 Boxer
$30, 2.5 oz. (small)
On numerous days of hiking and backpacking from the mountains of western North Carolina to an 80-mile, five-day backpacking trip in the North Cascades National Park Complex in Washington state—plus climbing, backcountry and Nordic skiing, and innumerable days at home—both of these boxer-briefs kept me wondering, “Why hasn’t anyone thought of this before?” Best-ever brand names aside, they are the two most comfortable models of underwear that I’ve ever worn. Through long days hiking—and sweating—for 15 or more miles, the MyPakage and Saxx boxer-briefs remained so dry and comfortable that I could wear the same pair in my sleeping bag that night and get a second day of use out of them (or more, if desperate).
The distinguishing feature of both is a three-dimensional pouch that cradles and supports a dude’s package, which is not only vastly more comfortable than standard briefs, but prevents chafing and sweaty contact against thighs, no matter how many miles you’re going. Both have lightweight, wicking fabric that breathes very well, dries fast, and is anti-microbial, so you really can wear them more than one day between washings; and both have comparably sturdy waistbands that don’t roll over, slip down, or bunch up. The Saxx inseam is an inch longer than the MyPakage; otherwise, the primary difference is in styles.
I expect this will mark the beginning of the end of the phrase “going commando.”
Smartwool Merino 150 Pattern Boxer Brief/Women’s Bikini
$45/$30, 3 oz. (men’s small)
Sizes: men’s S-XXL, women’s XS-XL
Smartwool’s Merino 150 wool feels just as soft and remarkably cool against your most-sensitive skin as it does against your torso and arms. Wool’s property of trapping heat when damp delivers welcome benefits in your anatomy’s deep south, too—which is why the Meino 150 Pattern Boxer Brief for men ($45) and Merino 150 Pattern Bikini for women ($30) are so comfortable for hours or even a couple of backcountry days. A wide, stay-put elastic waistband with a Merino lining in the men’s boxer brief, flatlock seams, and odor-killing properties completes this, um, package.
BUY IT NOW You can support my work on this blog, at no cost to you, by clicking any of these affiliate links to purchase the Smartwool Merino 150 Pattern Boxer Brief at moosejaw.com or rei.com, or the women’s Smartwool Merino 150 Pattern Bikini at rei.com.
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NOTE: I tested gear for Backpacker Magazine for 20 years. At The Big Outside, I review only what I consider the best outdoor gear and apparel. See my Gear Reviews page at The Big Outside for categorized menus of all of my reviews and my expert buying tips.