Choosing a base layer for hiking
When hiking, we often alternate between phases of intense activity and phases of rest. This tends to cause sudden rises and falls in body temperature, which can be dangerous for our health. The role of the first layer and of thermal underwear is to regulate this body heat and to evacuate the perspiration produced. It is therefore important to choose the right base layer for hiking. See our tips below.
Choosing base layer materials
Natural fibres
Clothes made from natural fibres (such as wool, merino wool or bamboo) are widely used for hiking. They provide natural warmth, are light and pleasant to the touch. In addition, they do not irritate the skin and have natural anti-microbial properties. This allows for excellent odour management. They are, however, quite fragile and may take longer to dry than garments made of synthetic fibres. We recommend that you use a natural fibre base layer if you are going on a multi-day hike. You can use them without any problem during hikes where you alternate between active and resting phases.
Beware, cotton clothing should not be used as a base layer when hiking. They are not breathable and absorb all the moisture produced by the body.
Synthetic fibres
Fibres such as polyester, polypropylene, polyamide or elastane also have many advantages. The garments dry faster than those made of natural fibres, are more durable and easier to care for. However, they are heavier, do not have as good an odour management and provide less warmth. You can wear them on a medium-intensity hike or on an intense but short hike. This allows you to have an effective base layer without suffering from odour.
Hybrids
Hybrid garments are made from a mixture of natural and synthetic fibres and are equally effective. The materials are distributed efficiently over the different body zones to allow good breathability and body heat regulation.
The importance of garment thickness
In the choice of base layer, the thickness of the garment is of real importance. Even if the role of the first layer is to allow good breathing and that of the fleece is to allow insulation, the thickness of the garment will impact on the heat produced. The thicker it is, the more insulating it will be, but also the less breathable. You will therefore choose your base layer according to your needs and the type of environment in which you will be working.
The weight of the fabric per square metre is often stated in the garment specifications. The higher the number, the thicker and warmer the garment. Here are some figures to give you an idea, they can vary depending on the material of the garment:
Below 150 g/m²: for intense activities or in high weather conditions.
Between 150 and 190 g/m²: for all-year-round use or in temperate to cold conditions.
Between 190 and 250 g/m²: moderate activity, ideal for colder conditions.
Above 250 g/m²: low activity or very cold conditions.
The cut of the base layer for hiking
Another important element in the choice of base layer for hiking is the cut of the garment. The fit can change depending on the activity. A cut that is too loose lets heat escape, but allows for greater ease of movement. A cut that is too tight has the opposite effect: it retains heat better, but restricts movement. For hiking, it is therefore best to find an in-between cut to obtain a base layer that is sufficiently tight to the body while allowing good freedom of movement.
Finally, the choice of seams should also be taken into account. More and more base layers are designed without seams or with flat seams. These have the advantage of providing extra comfort as they are not likely to cause itching due to the body rubbing during movement.
Choosing the right base layer for hiking is very important. It allows you to regulate your body heat. Depending on the intensity of your activity, its duration and the time of year, you can choose from different base layer models.