EN 
FR Who knows about layering, or the 3-layer system?
This is an unavoidable rule of the sports locker room.
It consists of choosing layers of clothing intelligently so as not to be hot or cold.
The secret is to adapt your clothing to the intensity of the planned effort and the outside temperature.
By promoting the proper evacuation of perspiration!
In the city, as we are leaving for the whole day without necessarily having the possibility to change, it is even more important. To optimise our well-being, we must :
- a breathable "first layer
- a breathable and warm "second layer
- a "third layer" that protects against cold and bad weather
1) Layering aims to keep you cool and dry
Sweating is the major cause of our discomfort during exercise.
It makes our clothes "stick" to the skin.
In order to reduce this discomfort, it is first necessary to limit the rise in our body temperature.
And encourage the rapid evacuation of moisture to the outside.
When hiking, this is how the system of the three layers optimises well-being and performance (see attached diagram of the site coureur des bois)
So to define what is good for the city, we will simply adapt the reasoning to our more formal outfits.
2) Does layering fit in the city wardrobe?
Thanks to Wolbe, yes!
1) the first layer must be breathable
It is the one we have direct contact with the skin. In the city, it will be a shirt, a polo shirta poloshirtor even a t-shirt which we will put under a pullover with button collar.
This is certainly the most important of the triptych, and often the most neglected. By evacuating the sweating It must be able to absorb the heat from the skin and avoid the feeling of cold due to evaporation of the skin. It must absorb the sweating easily and dry quickly.
The merino wool is undoubtedly the best material natural in the field. The scales on the fibre trap air bubbles that create an insulating film. This film keeps you cool when it's hot and warm when it's cool. This "regulated" temperature greatly delays the onset of the perspiration mechanism!
The Tencel keeps it cool.
Polyester is effective in terms of drying but not in terms of odour management.
Finally, cotton absorbs well but does not dry properly. When you know that 95% of men's shirts are made of cotton...there is a first inconsistency !
2) the second layer is thermal and breathable
Its role will be to slowly dissipate the heat produced by the body, to maintain a constant temperature. And above all to allow water vapour to pass through so as not to create a steam room effect under the garment.
The heat from this second layer must therefore be proportionate to the weather and the intensity of the activity. Therefore, one garment is usually not enough for all cases.
In the city, the second layerwill generally be a jumper, a blazera light jacket, a suit jacket or even a small sleeveless down jacket -body warmer-.
In terms of materials, there are no new features for breathability and odour. Merino wool, Tencel forward. Polyester not recommended if sensitive to odours.
Cotton is not recommended for large movements.
3) the third layer must be protective
It must be very effective against the outside elements: cold, rain, wind. Otherwise the heat will escape. And breathable if you plan to speed up.
Alternatively a car coat, a coat, a mackintosh, a parka, a windproof jacket.
This third layer is undoubtedly the most expensive and the most technical. It's up to you to decide what you want! The range of protections - and therefore of prices - is very wide.
Between a water-repellent jacket (chemically treated at the end of production to make water slide off... guaranteed only for a certain number of washes) and a fully waterproof jacket (thanks to a 20 m waterproof membrane and full thermal bonding), prices can be multiplied by 10.
Once again, the breathability of this third layer should not be overlooked: the intrinsic breathability of the fabric (thanks to breathable membranes from Sympatex® or Goretex®) or zips under the armpits...
3) Focus on relevant tips for optimal layering
- Be demanding about the ventilation of the last layer. It is as important as waterproofing if you are moving around. So there are several options: zips under the armpits, vents with a few holes, etc.
- use panniers instead of backpacks if you are cycling. No garment can really absorb the high impact of the pressure of the bag on your back... (here the brand Helmut made in France)
