How to choose ski or snowboard underwear.

A thermal base layer is the first layer of your skiing or snowboarding outfit, for which we usually talk about the three-layer rule (layer two being the fleece or down jacket, and layer three, the waterproof jacket).

Layer one is therefore the layer that sits in direct contact with the skin. We sometimes call it a "second skin" or a "base layer". Worn against the body, most of the time this consists of long or three-quarter tights and a long-sleeved t-shirt. The initial layers are designed using increasingly technical and smart materials, allowing you to find the best balance between wicking away perspiration and the generation of warmth, while also limiting odour.

Where there’s exercise involved, there’s perspiration: there’s nothing more annoying than a wet fabric that sticks to your skin and chills you to the bone as it cools down! One of the essential functions of sports base layers is to wick away moisture to keep you dry. The fabric used plays an important role: a first layer in cotton, for example, doesn’t help to wick away moisture. Rather opt for a technical synthetic material or Merino wool which offers many advantages.

If you sweat a lot or push yourself in terms of physical activity, certain thermal layers are designed with even more breathable fabrics in areas where perspiration is greater (the back, or the armpits for example).

Worn like a second skin, the thermal base layer is therefore the first layer of your outfit, lying underneath the insulating and waterproof layers. And we all know it, in winter especially at altitude, temperatures can be low to very low: in addition to wicking away moisture, this first technical layer therefore has a role in capturing and recycling body-generated heat. We’re talking here about thermoregulation!

Depending on the temperature, which sport and how you practice it, and your resistance to the cold, choose either long or ¾ ski leggings (which will prevent wrinkles in your ski boot) and a long-sleeved t-shirt with a reasonably high collar. Also pay attention to the fleece or vest that you’re going to wear, so you choose the right thickness for your base layer. If you have, for example, a second thick layer that’s really warm, of a fleece or down jacket type, it’s better to opt for a relatively thin thermal layer to prevent you from getting too hot.

We’ve said it before: where there’s physical activity, there’s perspiration and that undoubtedly brings with it, "odour". Certain fabrics get soaked in it, and it can be difficult to get rid of the smell, even after washing. Today there are many technical base layers on the market which are designed in odour-resistant materials, and which are ranked in different categories at Decathlon: very weak, weak, average, strong and very strong. You will find this information on the product sheet during your online search or on the shop shelves.

In addition, a synthetic product worn in direct contact with the body, combined with perspiration can create friction and irritation. To prevent this, you can opt for first layers made with flat seams and a material with a soft feel. Reference can be made to the SEAMLESS + or SEAM 0, which we find both for tights and for t-shirts (long-sleeved or not).