Layering of clothes
11.05.2021Everyone has certainly heard of layering outdoor clothing. Here we would like to summarize information and recommendations on how to dress effectively during active sports.
Layering of clothing
If you want to do sports even in colder weather, you have to rely on your own experience or get some advice on choosing clothes. You need protection from the cold and wind, but at the same time you need for proper functioning of the organism you need to maintain an optimal internal temperature. And it is this specific complex problem that the so-called “onion strategy” is trying to address. The temperature felt is individual, and the information or rules of combining the individual layers are always adapted to the current circumstances and equipment.
The basic requirement is the ability to react quickly to the interplay of external conditions and the intensity of physical activity. The role of clothing, materials and their combination is to find the balance between the effective body temperature important for performance and the external conditions.
Thermodynamics and something more: you know that: ...two systems with different temperatures will act on each other (conduction, radiation and flow) until their temperatures equalize... Insulating materials do not warm you up; they prevent the flowing of air (the insulating medium), which they retain in their structure. The coefficient of thermal conductivity of air is more than 40-times lower than the coefficient of water. Therefore, minimizing internal humidity plays a significant role in achieving optimal thermoregulation.
Performance intensity: the more intense your physical performance, the more heat your body produces. For the body to function properly, it needs the most ideal thermoregulation possible. Internal moisture can cool the body quickly, and the body cannot compensate for such a loss. The ideal materials should be elastic, breathable, adequately insulating or divided into insulating zones in terms of body mapping.
Overheated organism: the aim of the layering strategy is to prevent the body from overheating (>39°C) – excessive sweating can reduce performance, and damp clothing can freeze or cause hypothermia (<32°C) after exposure to the wind. You can avoid overheating by putting aside one layer or using the ventilation openings on the clothes.
Hypothermia: hypothermia most often occurs in the mountains for several reasons. The clothing insulates but is unable to rapidly remove the accumulated heat; it absorbs moisture, which together with the wind quickly lowers the temperature. Without the top waterproof layer you are exposed to the risk of getting wet with the same consequence. Insufficient, but also poor quality insulation is another common reason for hypothermia with increasing elevation.
Simulate nature
The onion strategy is based on functional layers. The bonus is a combination of various settings, but the possibility of quick exchange, replacement or reduction of any of them is essential.
1st layer
Functional underwear
Function: transports sweat from the body to other layers
Functional underwear is the base layer that is worn directly on the body. Its aim is to absorb and wick sweat away to the other layers of clothing, thus keeping the body dry and warm.
The material can be a synthetic like (Polartec® Power Dry™; Polartec® Power Grid™), or a natural fabric like merino wool. Although wool does not wick away sweat as efficiently as artificial materials, it does warm when wet. Furthermore, it has antibacterial effects and thus neutralizes odours.
Elastic fibres are added to underwear to mimic the body curves even during movement.
The combination of functional underwear with an elastic t-shirt, which creates a middle layer to a warming jacket or directly to thermal jackets, is an alternative. However, you’ll certainly want to avoid cotton underwear, which absorbs water and forms a cooling film around the body, causing all the other layers malfunction.
This layer includes functional underwear, socks, tank tops and light t-shirts with long or short sleeves.
2nd layer
Hoodies, sweaters, thermal jackets
Function: the insulation of body heat and the transport of excess heat in the form of vapour
The role of the 2nd layer (the middle or thermal insulation layer) is to prevent the loss of heat produced and to maintain an effective body climate, with the goal of ensuring optimal physical performance of the body, i.e. to simply ensure the correct “operating” temperature. This layer helps to transport internal moisture (sweat) caused by the body’s physical activity to the upper layer of clothing. The material again can be made of synthetic or natural fibres. Synthetic fibres have their advantages: they don’t absorb moisture; they transport it easily, possess adequate insulating properties and dry quickly. Among the synthetic insulation fibres suitable for intensive movement, the active insulation Polartec® ALPHA®,, which quickly regulates the body temperature thanks to excellent breathability, stands out.
This layer includes thermal insulation, sweatshirts, sweaters or vests.
3rd layer
Jacket, trousers
Function: protection against unfavourable external influences
he main roles of the third, outer, layer are to prevent getting wet and to block the wind, as well as to protect the layers underneath from mechanical damage in the field and enable the accumulated heat to be vented as much as possible.
Parameters
The outer layer should be waterproof, wind resistant, adequately flexible as well as breathable.The surface of the material is often treated with a hydrophobic layer that prevents the surface from getting soaking wet. Waterproofness limits breathability and vice versa. Experience shows that the laboratory values of even the most breathable materials are not sufficient for ventilation during intensive physical activity; therefore, the clothing is supplemented with ventilation openings.
The outer layer should be waterproof, wind resistant, adequately flexible as well as breathable.The surface of the material is often treated with a hydrophobic layer that prevents the surface from getting soaking wet. Waterproofness limits breathability and vice versa. Experience shows that the laboratory values of even the most breathable materials are not sufficient for ventilation during intensive physical activity; therefore, the clothing is supplemented with ventilation openings.
Water column
The water column shows the overall measure of water resistance under the assumption that the construction of the garment has all the seams taped. The necessary protection is provided in particular by laminated materials with a porous membrane (hardshell). The offer is supplemented by laminated softshell materials, which, aside from being waterproof, also offer optimal mobility due to their flexibility. Densely woven materials (Pertex®) with a surprising ratio of weight, waterproofness and breathability are available. The waterproof, non-porous membrane with excellent elasticity but weaker breathability – Dermizax™ – stands alone.
Breathability
This parameter stands in direct contrast to waterproofness. But to solve this dilemma, it is enough to realize that external humidity in the form of a molecule of water in the liquid state is several times greater than a molecule of vapour. The pores of the membrane are too small for external moisture to enter but they do allow accumulated vapour to escape. We express breathability as the weight of the vapour released from the area of a square metre per day (g / m² / 24 hours).
Jackets
We present the advantages of individual types of jackets in a clear list.
Hardshell jacket
+ Membrane guarantees waterproofness
+ Taped seams
+ Hood is usually part of the jacket
– Hadrshell material is less breathable, thus it is less suitable for active sports
– Minimum insulation function
– More expensive variant
Softshell jacket
+ The jacket is breathable,
+ Softshell jackets are insulated on the back with a fine layer of fleece,
+ The material is pliable and flexible
+ Cheaper variant
– The material is partially waterproof, but in heavy rain it lets water in
– Often an absence of taped seams
Test and combine, a different combination is appropriate for each activity and temperature condition. Remember, there is no bad weather, only ...
