Adult Base Layer Top Keepwarm 900 - Dark Grey


Our team of football product designers has created the Keepwarm 900 base layer for footballers playing in very cold weather.

The Keepwarm 900 base layer offers great protection from the cold. It is recommended for playing in temperatures of -10°C to 7°C and wicks away perspiration to keep your skin dry.

Color: Carbon grey / Dark grey
Size: size guide


Eco designed

Learn more about Eco-Designed Products.

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Product benefits


Thick fabric that is soft on the inside for excellent warmth.


Patented i-soft technology lets moisture escape more effectively to keep you dry


The main thread is Dope Dyed, which is a process friendlier to the environment.

Freedom of movement

The fabric is stretchy and the garment is designed for freedom of movement.

Technical information

Why wear a base layer?

The base layer, also known as the inner layer, helps:
. Absorb and remove perspiration. Your skin stays dry and your body does not get cold. .Retain body heat by being close-fitting. .Offer an additional barrier against the weather
. Keep your football shirt dry, even when you're running hard.

Playing with a technical base layer keeps you on the pitch for longer.

What our design team has to say

Every player needs to be comfortable when training, even in very cold weather. This is why we have made this base layer great at wicking away perspiration and retaining body heat.


This under-jersey top is made from a weave of a polyester thread that helps wick away perspiration, and a polyamide thread for greater softness. These two materials, combined with elastane, ensure excellent comfort. A raised collar and thumb loops provide added protection from the cold.

Our field tests in a climate chamber

Our range of "very cold weather" base layers was tested in a climate chamber with a group of 30 athletes in January 2020. The climate chamber allows us to perform all tests in the same climatic conditions (temperature, wind). Our certification department uses a strict protocol to assess the classification of the garment's ability to keep your skin dry, retain body heat and prevent shivering. 1.Keepwarm 900
2. Keepdry 900
3. Competitor product

Patented i-Soft technology

Created by our Italian industrial partner, the patented i-Soft technology makes it possible to put together a garment that is warm, ultra-breathable, and seamless. The thick fabric, brushed on the inside, disperses perspiration very effectively despite its relative thickness. The final product combines warmth and perspiration dispersion, making it perfect for high intensity sports activities.


When paired with the Keepwarm 900 tights, they form a complete outfit that protects you from the cold very well.

Dyeing processes to improve our environmental impact

Dope Dye is used on the polyester threads.Mass dyeing is the introduction of pigments during the thread production process. It has a lower environmental impact on water (use & pollution) and there are several environmentally friendly dyes.

A rating for comparing products environmental impact

The product's environmental impacts are calculated throughout its life cycle and with different indicators. An "ABCDE" rating system has been created to help you quickly see which products offer the best environmental performance. Use it to compare two similar products (T-shirts, bottoms, backpacks). Decathlon actively promotes this visible environmental rating policy. Web:
Explanatory video:


2 years

Product concept & technology

Product Composition

Main fabric 66% Polyester, 29% Polyamide, 5% Elasthane

Maintenance advice

Machine wash - 30° max - normal

Do not bleach

Do not tumble dry

Do not iron

Do not dry-clean


Customer reviews


Environmental Impact

The carbon footprint of this product is:
6.84 kg CO2e
1 kg of CO2e represents 5km in a petrol car (according to the Base Carbone© of ADEME)
What's the carbon footprint ? We evaluate the environmental impact of all our products. At all stages of their life cycle: from the extraction of the raw material, passing through transport to the plant which transforms them, the transformation, the manufacture, the transport of the finished product, until its use and end of life. Find out more
The environmental note of this product is: B
What is the environmental note? Overall environmental score for this product in comparison to others in the same category. It is calculated based on its impact on the environment (air and water emissions, greenhouse gas emissions, depletion of natural resources) at each stage of its life cycle, according to a system managed by ADEME. Find out more