Have you ever wondered what makes your sports leggings so stretchy? Or why some sports bras are comfy and breathable, and others are itchy or cause a rash? Perhaps, like us, you’re committed to sustainability and want to know where your clothes come from and what happens to them after you’re done. Well, you’re in the right place.

This post will cover the big question of ‘what material is sportswear made from?’ by comparing the sustainability and performance features of popular sportswear fabrics and introducing you to Tripulse’s top choice: Tencel.

We’ll walk you through the whole life cycle, from production to after-life, so you’ll be completely clued up on your sports clothes’ material. And if a big read just isn’t for you, don’t worry we’ve shrunk it down to a table at the end.

Now let’s get started!

What material is sportswear made from?

In this post, we challenged you to gather all your sportswear together and read their material labels, and answer one question – how many of your sports clothes contain polyester? Our guess was the vast majority.

That’s because polyester has long been the favored sportswear fabric. Though flexible, durable and cheap to make, it’s essentially plastic and derived from fossil fuels. This means it isn’t the best choice for the planet.

Another popular choice is nylon, a type of polyamide. Polyamide refers to the molecular structure of a fiber, whether that’s synthetic or natural, however natural polyamides (like silk and wool) are simply referred to by their fiber name. Therefore, when we talk about polyamides, we’re referring to synthetic kinds. Nylon is the most common for sportswear, but there are others like kevlar and nomex. Like polyester, synthetic polyamide fabrics are also derived from fossil fuels and used for their strong and durable nature.

Alternatives are growing in popularity too, such as recycled versions of synthetic fabrics, and natural materials like bamboo and organic cotton. There are also new and innovative options such as our top choice: Tencel.

Tencel is a lyocell fiber derived from sustainable wood sources invented by the Austrian wood fiber company, Lenzing. It’s naturally high-performance, breathable, and odor-resistant, as well as sustainable.

The four types of fabric used in sportswear we’ll dive into are:

  1. Virgin polyester
  2. Recycled polyester
  3. Polyamides
  4. Nylon
  5. Tencel

The sportswear lifecycle

Now you know what material sportswear might be made from - popular synthetic materials and up-and-coming innovative natural alternatives – it’s time to consider the lifestyle these sportswear fabrics go through.

Our comparison will cover these stages:

1. The raw material origin
The fabric before it became, well, fabric. Whether it’s from a renewable or non-renewable resource.

2. The production process
How the sportswear fabric is produced, including the energy needed and resulting CO2 emissions, and the substances that are typically used to make these fibers.

3. Usage
The key features you need for sports, like breathability and odor/ bacteria resistance, how they react with your skin, and the microplastics released during washing.

4. End of life
Their recyclability or biodegradability.


A complete comparison

1. Raw material

Virgin polyester is essentially plastic, derived from non-renewable fossil fuels like crude oil and petroleum. It’s a man-made synthetic fabric and the most common form of polyethylene terephthalate (PET), the same material used in plastic bottles.

Recycled polyester, sometimes known as rPET, uses existing plastic as its raw material. This diverts rubbish from landfills and reduces the demand for non-renewable resources.

Polyamides, including nylon, come from petroleum and different chemicals.
Nylon comes in different forms, but the most common in the fashion industry is nylon 6,6, which combines two molecules found in petroleum: adipic acid and hexamethylenediamine.

Tencel is an innovative fabric that comes from trees. Yes, you heard us right. It’s made from wood pulp from sustainably managed forests, including eucalyptus, pine, spruce, and birch trees. So, it’s from a renewable resource.

2. Production and CO2 Consumption

Virgin polyester requires a hefty process. The chemical industry supplies PET pellets to the textile industry, which converts them into fibers by adding alcohol and carboxyl, and then it’s spun into fabric. Polyester is known for being easy to colour using synthetic (disperse) dyes. This whole ordeal is energy-intense and polluting: it requires as much as 125 MJ/kg and results in the emission of 27.2 kg CO2/kg.

Recycled polyester is obtained by melting down existing plastic, such as bottles and containers thrown away by consumers. The process of converting PET into recycled polyester requires 33-53% less energy than virgin normal polyester. However, it can impact the planet as toxic chemicals like chlorine-based bleach are often used.

Polyamides, such as nylon, are made by creating a chemical reaction in a high-pressure and high-heat environment. Diamine acid is and forced to mix with adipic acid to form nylon salt, which is then melted, spun, and stretched into a fabric. It’s an energy-hungry process that requires 85 MJ/kg. Producing nylon releases nitrous oxide, a greenhouse gas that has been reported as 300 times worse than CO2.

Tencel is made from a circular process free from toxins. The cultivation of the wood pulp does not require the use of pesticides or artificial watering. In terms of energy, it requires only 21 MJ/kg, and for emissions, it produces just 4.6 CO2/ kg.

 

3. Usage

Polyester (virgin and recycled) is a popular sportswear fabric because of its performance features. It’s durable, breathable, and lightweight. On the flipside, it easily develops odor and grows bacteria (which isn’t great when you’re getting sweaty!). As it contains toxic chemicals like benzothiazole and benzotriazole, the fabric can cause allergies, itches, and eczema on the skin. When it’s washed, it releases around 500k microplastics per wash load.

Nylon, the most popular polyamide for sport, is known for being incredibly stretchy and elastic, making it a top choice for activities like swimming, dancing and cycling. Thanks to its low absorbency, it dries faster than other fabrics, and it’s also waterproof, hence why it is sometimes used in swimwear. However, synthetic nylon is a great refuge for odor-causing bacteria (like Propionibacterium acnes) and forms microplastics when washed.

Tencel has many high-performance features perfect for every workout. It's highly breathable and also durable. Like cotton, it feels soft and caring on the skin. The biggest bonus with Tencel, though, is that it’s naturally anti-bacterial and odor resistant. As a wood-based material, no microplastics are released when it’s washed too.

4. After-life

Virgin polyester, being a plastic, takes hundreds of years to biodegrade. That said, it is possible to recycle the fabric if it’s not mixed with other fabrics (more reasons to read the label!).

Recycled polyester is also non-biodegradable. It’s debated whether it can be recycled again and again to eventually become a closed-loop system, or if it decreases in quality each time. Either way, it stays out of landfills for longer than its virgin alternative.

Nylon is also non-biodegradable. Like polyester, it can be recycled, and there are many brands out there trying to find ways to find a more sustainable and closed-loop system for dealing with nylon waste.

Other polyamides may be biodegradable depending on the fiber content, but identifying biodegradable synthetic polyamides is a tricky business. It depends on the type of polymers it contains which normally isn’t transparent.
Tencel lyocell fibers are certified as biodegradable and compostable, meaning that they can revert back to nature in a relatively short amount of time depending on the environment.

Tripulse’s Choice: Tencel

In this post we set out to answer the question ‘what materials is sportswear made from?’ by giving you not just the names, but the origins, production, usage, and afterlife of popular sportswear fabrics and our favorite alternative.

Although there’s no denying polyester has its perks, and even nylon has nice features, they clearly have their downsides. They harm the planet, aren’t easy to get rid of, and can irritate your skin and health over time. Even recycled polyester, though slightly better as it uses existing material, sheds microplastics, attracts bacteria and can cause strong skin irritations. 

That’s why Tencel ticks the most boxes for us. Now you know all about sportswear fabrics, we hope it ticks the boxes for you too. We’d love you to try this innovative alternative out for yourself and let us know what you think!

 

 Material Raw Material Production  Usage Afterlife
Virgin polyester


Crude oil and petroleum (non-renewable)

Requires as much as 125 MJ/kg and results in the emission of 27.2 kg CO2/kg.



Durable and lightweight.

Can cause skin irritation, allergies & other health issues.

Releases around 500k microplastics per wash load.

Non-biodegradable.

Can be recycled if not mixed with other fabrics.
.






Recycled polyester Existing plastic, crude-oil based (non-renewable)

 Requires 33-53% less energy than virgin polyester but may use toxic chemicals.

See above

Non-biodegradable.

Can be recycled, though may reduce the quality of fabrics and often requires adding virgin polyester.


Polyamides / Nylon
Combine two molecules found in petroleum (non-renewable) Requires 85 MJ/kg and releases nitrous oxide. Stretchy, elastic, low absorbency, and waterproof.

Attracts odor-
producing bacteria and releases microplastics.

Non -biodegradable, but can be recycled f not mixed with other fabrics..

Other nature-based polyamides may be biodegradable depending on the fiber content, but it normally isn’t transparent.

Tencel
(Tripulse  choice)
Sustainably sourced & certified wood fibers (renewable)

Circular process free from toxins, requires 21 MJ/kg and releases 4.6 CO2/kg.

Highly breathable, naturally odor-resistant, soft, and durable. Does not release microplastics. 100% biodegradable, if not mixed with non-biodegradable fabrics.  

 

Sources:

(1) https://silverbobbin.com/what-is-polyamide-fabric/

(2) https://www.sciencedirect.com/topics/engineering/hexamethylenediamine

(3) https://enveurope.springeropen.com/articles/10.1186/s12302-020-00447-x#Sec24

 (4) http://utw10945.utweb.utexas.edu/Manuscripts/2010/2010-26-Telenko.pdf

(5) https://theconversation.com/meet-n2o-the-greenhouse-gas-300-times-worse-than-co2-35204

(6) https://www.hello-ben.com/pages/the-conscious-fas-guide

(7) https://fashionunited.uk/news/fashion/how-sustainable-is-recycled-polyester/2018111540000

May 12, 2022 — Franziska Mesche

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