As a second skin functional underwear plays an important role in the onion principle

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Funktionsunterwäsche von Odlo
The ideal base layer for being active outside

What kind of base layers do you wear? Synthetic or wool?

I’m sure you’ve heard this question before on one of your hill walking or mountain biking adventures. As inappropriate as the question may seems initially, it’s not at all unusual for us outdoorsy folk to want to know somebody else’s clothing technique. After all, it’s an extremely important question! Regardless of whether you’re mountain biking, trekking or climbing, ideal underwear is something that always comes up.

But what kind of underwear is right for you? And, what’s the difference between them, anyway? I mean, really, it’s just underwear! Well, there are plenty, so we’ve taken it upon ourselves to summarise all you need to know when it comes to finding a great pair of underwear.

Why do you need special base layers?

Drei Frauen in Funktionsunterwäsche
Layering is essential

Functional base layers play an extremely important role in all those layers of clothing we outdoor enthusiasts across the globe have been wearing now for quite some time. Functional underwear is usually worn right up against your skin. Its purpose is to manage moisture, meaning that it is supposed to wick sweat away from our bodies to the next layer of clothing.

If loads of moisture accumulate underneath a highly breathable hardshell jacket, it won’t be able to function properly. Plus, if the wet underwear sticks to your body, you will get cold very quickly, especially during breaks. Your performance will suffer as a result. Thus, it is of utmost importance that your functional underwear does not soak up moisture like a sponge or cotton T-shirts.

Decisions, decisions: buying functional underwear

The type of functional underwear you end up purchasing depends on the intended use. Of course, the underwear should be much lighter in summer than it would be in winter. Not only do some of us sweat more than others, but we also have differing opinions on when that clammy feeling has crossed the line and made us incredibly uncomfortable. So, next-to-skin comfort is very important to keep in mind.

Regardless of what kind of functional base layer you end up buying, it should be comfortable and be close-fitting. Flat seams and elasticity are other important factors. Ideally, your functional underwear should not only provide warmth when wet, but it should also dry quickly. And last but not least, your functional underwear should be odour-resistant – even after extensive wear!

There are different kinds of functional underwear:

  • Natural fibres such as silk (not as common, since it feels cold very quickly) or merino wool (good insulation even if it gets wet, odour-inhibiting properties)
  • Synthetic fibres such as polyester, polypropylene or polyamide.
  • Blended fabrics, which combine the advantages of both and thus offer options that are tailored to specific purposes

Synthetic fibres – innovative and very functional

Synthetic fibres have the ability to quickly absorb and transfer perspiration away from your body and to then dry very quickly. Plus, they are light and easy to clean. Thus, functional underwear made of synthetic fibres is particularly good for summer activities, for those of us who just sweat in bunches or those of us who don’t like how wool feels against our skin.

Ist es warm und trocken wird das Baselayer zur obersten Kleidungsschicht.
Functional base layers made of synthetic fibres are suitable for mountain running, cycling tours and other high-intensity activities.

If you love those long and challenging mountain runs, cycling trips or any strenuous physical activities, synthetic fibres are a great choice.

Optimal comfort is often achieved by incorporating a high percentage of elastane, which makes the garment very stretchy. Various treatments, such as Polygiene or the innovative S.Cafe, serve to equip the synthetic fibres with odour-inhibiting properties, which allow you to wear the garments for multiple days at a time.

It may come as a surprise to some, but synthetic fibres have been around for quite some time. Manufacturers like Odlo have been providing and improving their highly functional clothing for a very long time.

Wool – insulating and odour inhibiting

Wool has several advantages that have been well known for centuries. Even though merino wool has taken a backseat to synthetic fibres in recent years, it is now making quite the comeback. One advantage of this renewable resource is its ability to repel moisture to a certain degree.

Because wool consists of up to 85% air, it provides optimal warmth as well. Wool is also anti-static and resistant to any sparks from the campfire. In addition, merino wool has odour-inhibiting properties as well. Wool is also self-cleaning, meaning that it doesn’t hold smells or odours. Thus, your functional wool garments will smell nice and neutral again, even after a long and exhausting hill walk. A plus for all your travelling buddies!

Functional underwear made of merino wool is thus suitable for longer treks and hill walks, ideal for skiing or other activities where you tend to linger or take breaks.

Merinoschafe liefern die feine Merinowolle.
These fluffy sheep provide the wonder wool for your functional base layers

Today, merino wool is used by a large number of manufacturers. One of the best known brands is certainly the New Zealanders at Icebreaker whose stylish base layers play a significant role in the merino wool’s recent boom.

However, very traditional manufacturers, such as Woolpower from Sweden, have also been producing merino wool clothing for decades. They add a small amount of synthetics to create an incredibly resilient and long-lasting garment that Woolpower refers to as a “supergarment” (machine washable at 60˚C!).

Tailored to the needs of the wearer

There are several ways to dress on the go that are tailored to your intended use and personal preference. Functional underwear is only one layer of many.

In summy

  • Synthetics are good for high temperatures or sweat-inducing activities
  • Merino wool for colder weather

At the end of the day it comes down to personal preference. People who sweat quickly even in winter should opt for synthetic base layers. Those who tend to get chilly can also use wool in summer.

If you choose the right base layer, you will have more fun on your tour, feel comfortable and feel fresh and fit for longer. And that really is the basis for any outdoor experience!

Base layers for you >>

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Alpinetrek-Expert Simon

Alpinetrek-Expert Simon

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