Layering is the key to keeping warm and comfortable outdoors – and since the bottom layer is the one that’s next to your skin, it’s the most important one to get right. A snuggly thermal base layer can be a lifesaver for snow sports or all-weather hiking; in warmer conditions, sweat-wicking tops and bottoms worn on their own are also ideal for climbing, cycling and any number of other outdoor pursuits.
In short, a good pair of leggings and a matching long-sleeved top can serve you well all year round. It’s worth investing in a high-quality set – and we’ve picked our six favourites for men and women.
How to pick the right base layer for you
A good base layer should fit closely to your skin without being restrictive; ideally it will have some stretch and give, so it clings to your body when you move, keeping the warmth in. When you try on leggings and tops, check that you can move your arms and legs freely, with no baggy space for cold air to get in. In particular, look for snug cuffs on arms and ankles; we always look for a wide, comfortable waistband on leggings too. If you’re taller or shorter than average, remember to check the lengths of sleeves and trouser-legs.
What material should I look for?
Base layers are usually made from either synthetic materials – such as polyester or a polyester blend – or natural materials such as merino wool. The advantages of polyester are that it’s very light and quick to dry, and it can be quite cheap.
Merino wool (either 100% merino or a stretchier blend) tends to be pricier, but it’s naturally antibacterial, and can be better at wicking away sweat, so it typically doesn’t need washing so often – perfect if you’re planning an extended camping trip that will take you away from showers and washing machines for a few days.
Wool base layers can be slightly itchy, however, so they’re definitely worth trying on in person to check before you buy. You may also find that a merino blend will have more stretch than pure wool. A third, relatively new option, is bamboo base layers, which are also antibacterial and often wonderfully soft to wear.
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The best base layers for men and women
1. Odlo Blackcomb Evolution (for men and women): Best base layer overall
Price: From £50 | Buy now from Odlo
We’ve put Blackcomb Evolution base layers through months of outdoor adventures, and they’ve never let us down. These soft synthetic garments are comfortable and form-fitting (yet still flattering), with a ribbed shape that stays put all day – and they’re so light it barely feels like you’re wearing anything at all. They’ll keep you snug in snow, but are breathable and comfortable enough to wear alone, and they’re durable too: we’ve washed them multiple times and they always come out looking and performing like new. Tops are available with and without high necks, and with an optional facemask built in for the coldest climates.
Key specs – Material: Various; Stretch: Yes; Sizes: XS-XL; Colours: Blue, purple, grey, green
2. Sweaty Betty Moto (for women): Best base layer for fashionistas
Price: From £65 | Buy now from Sweaty Betty
A cult favourite among fitness bloggers, Sweaty Betty’s slick, retro-looking base layers aren’t just good-looking – they’re wonderfully comfortable and warm to wear. The seamless design means they won’t dig in anywhere, and they’re ideal for sports and fitness, as well as providing warmth when out and about. We particularly like the high waist and wide waistband on the leggings: our only criticism is that the insides are quite delicate, and threads can come loose if you catch them on jewellery.
Key specs – Material: Various; Stretch: Yes; Sizes: XS-L; Colours: Black
3. Bergans Snoull (for men and women): Best base layer for skiing and snow
Price: From £94 | Buy men's now from Bergzeit | Buy women's now from Amazon
A luxury merino wool option for men, the Snoull is a high-necked, half-zip base layer that’s a little heavier and looser than most; you might choose to wear it over a light, tight-fitting T-shirt. The material keeps in warmth while wicking away sweat and stopping odours in their tracks – so it’s a great choice for long days outdoors, or multi-day camping expeditions. Bergans also does a great line in base layer-style, longer cut underwear that’s ideal for frosty days.
Key specs – Material: Merino wool; Stretch: No; Sizes: L; Colours: Blue
4. Montane Primino 140 (for men and women): Most versatile base layer
Price: From £50 | Buy now from Amazon
Clever Montane offers two lines of base layers – 140 and 220, named after their respective weights. These lighter 140g pieces are ideal for summer sports, while their heavier counterparts are more suited to snow sports and winter hiking. You can choose from a range of tasteful colours, and long and short sleeve styles, as well as liner gloves, buffs and underwear; it’s hard to resist building up an entire wardrobe! We particularly love the mix of merino wool and stretchy warm PrimaLoft – a combination that’s warm, sweat-wicking and faster to dry than 100% merino.
Key specs – Material: Merino wool and PrimaLoft; Stretch: No; Sizes: S-XXL; Colours: Black, blue, red
5. Under Armour Cold Gear (for men and women): Best base layer for sports
Price: From £30 | Buy now from Under Armour
A firm favourite with gym fans and sporty types, Under Armour’s Cold Gear range can be relied on when temperatures drop. A simple, slick design and a beautiful fit make them a joy to wear, and we found the great stretch from the Elastene was ideal for more vigorous activities. What’s more, even though the price is low, of all the base layers we’ve tested, these proved the fastest to dry, and the best at wicking away sweat. Perfect for anyone who likes to get really active in the great outdoors.
Key specs – Material: Polyester and Elastane; Stretch: Yes; Sizes: XS-XL; Colours: Various
6. BAM bamboo base layer jersey (for women): Best for the back country
Price: From £35 | Buy now from Bamboo Clothing
Ultra-comfy, organic and highly breathable, bamboo is a fantastic material for sportswear. And BAM’s base layers, with their comfy crew necks and thumb holes, aren’t just comfortable – they’re smart enough to wear as regular tops and leggings, not to mention great value for money. Effective antibacterial properties also make bamboo a treat for camping or back-country expeditions: you can hike for days in this base layer jersey without offending the noses of your hiking companions.
Key specs – Material: Bamboo; Stretch: No; Sizes: 8-16; Colours: Black, blue