Columbia Tunnel Springs Wool Tights review: premium thermal protection for legs

These mostly merino Columbia Tunnel Springs Wool Tights base-layer bottoms keep your legs warm through winter

Columbia Tunnel Springs Wool Tights
(Image: © Pat Kinsella)

Advnture Verdict

Dynamic underwear, the Tunnel Springs Tights from Columbia provide excellent thermal protection for your legs in a wide range of outdoor scenarios during the colder months, from hiking, biking, running, climbing and skiing through to chilly nights spent in a sleeping bag that would be sleepless without them. Lightweight, but with a hefty price tag, they are a premium product that needs to be carefully looked after, but they’re well made, using high-performance fabrics with a comparatively light eco footprint, and should last you for many winters.


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    Great next-to-skin comfort

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    Good thermal properties

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    Merino content regulates heat

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    Excellent moisture wicking

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    Can be worn several times between washes

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    Eco-friendly composition


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    No foot stirrups so legs can ride up

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    Require careful laundering

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Meet the reviewer

best fleece jackets: Artilect Halfmoon Bio Pullover
Pat Kinsella

Pat has hiked all over the world, his adventures taking him to Mont Blanc, the roof of Western Europe; the Norwegian Alps; the highest peaks on Australia; and New Zealand’s Great Walks – among others. He’s an experienced tester of hiking footwear and gives each pair a thorough thrashing before reviewing.

Columbia Tunnel Springs Wool Tights: first impressions

Made with a material mix that’s majority merino wool, these thermal leggings accompany the Columbia Tunnel Springs Wool Crew Baselayer top to supply a full-body base layer suit of soft, protective armour designed to help you keep comfortable in cold conditions while exploring the outdoors. 


• List price: $90 (US) / £70 (UK)
• Weight: 200g / 7oz
• Gender specification: Men’s and women’s versions available
• Materials: 60% merino wool, 40% lyocell
• Sizes: XS / S / M / L / XL / XXL
• Colors: Black / Night Wave
• Compatibility: Snow sports, midwinter hiking and biking, shoulder season backpacking and camping

It is, it has to be said, a pretty expensive thermal underwear combo, but the garments are made with an eco-minded and high-performing material mix of merino wool and lyocell. 

The benefits of the former are well known: merino wool is a natural and near-magical material that keeps you warm in the cold (even when wet) and cools you when it’s hot. It feels lovely next to your skin, breathes beautifully, wicks moisture away from your body with aplomb, contains proteins that break down stink-causing bacteria and can be worn for several days without needing to be washed. 

All of these properties make merino a perfect ingredient for technical underwear, but it’s not especially robust, especially at a low GSM, and no one wants to wear thick undies. So Columbia have mixed it with lyocell, a tougher fabric made from the fibers of wood (mainly eucalyptus), which has been heralded as an eco-friendly alternative to cotton and synthetics such as polyester.

Columbia Tunnel Springs Wool Tights

The Tunnel Springs Wool Tights have flat seams and a comfy elasticated waist (Image credit: Pat Kinsella)

Both the Tunnel Springs top and tights are armed with Omni-Wick technology, which Colombia claims offers enhanced wicking capability to move moisture away from your body to exterior of the garment, where it can evaporate. I’m not disputing this happens – both garments do indeed wick moisture very well – but I do rather think this is just one of the many naturally occurring properties of the merino wool material that features so heavily in the content of the clothes, which the brand has cheekily rebadged as something they invented. It’s still a great feature, I just think the sheep should get a little more credit, instead of the product designers taking all the glory.

The Tunnel Springs Tights feature flat seams and elasticated waist and ankle bands, which comfortably keep them in place when you’re out and about, but there are no foot stirrups (which can be a mixed blessing anyway, with many people disliking the band that runs under your foot).

Columbia Tunnel Springs Wool Tights: in the field (and in the sack)

Columbia Tunnel Springs Wool Tights

Columbia Tunnel Springs Wool Tights aren’t designed for running in, but you can use them happily for that purpose, and I thought you’d prefer these photos to me looking like an underwear model (Image credit: Pat Kinsella)

I’ve been wearing my Tunnel Springs tights during hut-hiking escapades in the French Alps and on chilly winter walks and frosty trail runs in the south of England, as well as during some cold nights sleeping out.

I love merino garments, and these tights are sumptuously comfortable to wear, with no prickliness or itchy irritation at all. While using them overnight, effectively as thermal pyjamas in a sleeping bag, they just kept me warm and I completely forgot I was wearing them. Perfect. 

When I wore them under hiking trousers and rain pants it was a similar story – they just kept my legs nice and toasty without being noticeable or impeding my movements at all. I haven’t had the opportunity to wear them beneath salopettes or ski pants in the snow yet, but I’m confident they will perform perfectly in such a scenario.

Columbia Tunnel Springs Wool Tights

But being majority merino in composition, they’re not the most rugged garments, so keep them away from brambles (Image credit: Pat Kinsella)

On several especially frosty mornings I’ve been out running in them, and while they’re not quite as suited to this purpose as a good pair of purpose-built running leggings (with a merino material finish, the Tunnel Springs garments are designed primarily as underwear, and can easily snag on brambles), they did a good job of keeping me warm while wicking moisture away.

I wore them beneath running shorts, which did leave me with the old dilemma of whether undies should be worn beneath tights in such situations… and I can happily report that the Tunnel Springs can comfortably be worn commando style without any irritation.

Columbia Tunnel Springs Wool Tights

The brand may have come up with the name Omni-Wick but we think most credit for its moisture-wicking prowess should go to the sheep (Image credit: Pat Kinsella)
Pat Kinsella

Author of Caving, Canyoning, Coasteering…, a recently released book about all kinds of outdoor adventures around Britain, Pat has spent 20 years pursuing stories involving boots, bikes, boats, beers and bruises. En route he’s canoed Canada’s Yukon River, climbed Mont Blanc and Kilimanjaro, skied and mountain biked through the Norwegian Alps, run an ultra across the roof of Mauritius, and set short-lived records for trail-running Australia’s highest peaks and New Zealand’s Great Walks. He’s authored walking guides to Devon and Dorset, and once wrote a whole book about Toilets for Lonely Planet. Follow Pat’s escapades on Strava here and Instagram here.