TENCEL™ Lyocell vs Polyester: Which Is Better for Activewear?
Polyester has dominated the activewear industry for decades, offering durability, stretch and moisture-wicking performance. But with a growing need for healthier and more sustainable options, could TENCEL™ Lyocell be the answer for performance sportswear?
At REAL DREAM STATE®, we've spent the past few years testing and researching natural-fibre fabrics to see whether they can meet the demands of high-intensity movement, particularly running.
One fibre that continues to stand out is TENCEL™ Lyocell.
What Is TENCEL™ Lyocell?
TENCEL™ is a fibre brand developed by Austrian manufacturer Lenzing. Lyocell is a regenerated cellulose fibre, produced by dissolving wood pulp, usually from sustainably sourced eucalyptus plants, and reforming it into fine textile fibres.
Although its origins are natural, TENCEL™ Lyocell is not an entirely unprocessed natural fibre. It undergoes a chemical manufacturing process to transform the cellulose into a material suitable for textile production.
Lenzing uses a closed-loop process that recovers more than 99.8% of the solvent used during production, allowing it to be reused. The regenerated fibres are then washed, finished and dried.
The resulting fibre is known for its smooth surface, softness, breathability and cooling effect on the skin, while also being strong and having the ability to absorb and release moisture.
These characteristics make it viable for garments worn close to the skin, where comfort and moisture management are essential.
What Is Polyester?
Polyester is a synthetic fibre, most commonly made from polyethylene terephthalate (PET), a plastic derived from fossil-based chemicals.
Its widespread use in activewear is largely due to its durability, low cost and ability to be engineered into lightweight yet strong, quick-drying fabrics.
When combined with elastane, polyester can also create highly supportive fabrics with excellent stretch and recovery, making it particularly suitable for compression garments.
High-quality polyester fabrics can be exceptionally durable and long-lasting, withstanding repeated washing, stretching and abrasion.
However, polyester's reliance on fossil-based resources contributes to microplastic pollution, with plastic fibres shedding and ending up in our environment, including our waterways and household dust, eventually making their way into our bodies.
There is also growing concern around chemical finishes used in textile manufacturing and their potential implications for human health. These concerns aren't exclusive to polyester, but they reinforce the importance of understanding how our clothing is made and what processes are in place to eliminate these toxic chemicals.
Certifications such as STANDARD 100 by OEKO-TEX® can provide additional reassurance that a textile has been tested against defined limits for specified harmful substances.
Moisture Management and Breathability
One of the most important considerations when developing activewear for running is how a fabric manages sweat.
TENCEL™ Lyocell and polyester approach this in different ways.
TENCEL™ Lyocell absorbs moisture into the fibre itself. Its cellulose structure contains hydroxyl groups that attract water molecules, allowing moisture to move into the fibre rather than remaining entirely on its surface.
This helps regulate humidity between the skin and fabric. As moisture is absorbed and released, it can contribute to a more comfortable microclimate, providing a natural cooling effect. It is ultimately more breathable and just feels better.
Polyester, on the other hand, absorbs very little moisture internally.
Instead, specially engineered polyester fabrics transport sweat through tiny spaces between fibres and yarns, using a process called capillary action. Moisture spreads across a larger surface area, encouraging evaporation.
Some polyester fabrics also use different chemical and hydrophilic finishes, which make the fibre surface more receptive to water and improve moisture transport.
Both approaches have advantages.
Polyester generally excels where rapid drying is essential. TENCEL™ Lyocell can offer a different type of comfort by managing heat and sweat within the fibre itself.
However, higher moisture absorption can also mean retaining more water, potentially increasing garment weight and drying time.
Odour Control
Anyone who regularly exercises in synthetic clothing knows how garments can retain odour, even after washing.
TENCEL™ Lyocell offers an advantage in this area. Lenzing's research suggests its moisture-management properties can create less favourable conditions for certain odour-associated bacteria compared with polyester.
From my own experience, this has been one of the most noticeable differences.
I've found that some of my TENCEL™ blend leggings can be worn for multiple workouts before needing to be washed, something I found really crazy at first and would never dare to do with my synthetic activewear.
Of course, this is personal experience rather than a controlled scientific comparison, and odour development depends on several factors, including fabric construction, skin bacteria and washing habits. But it's certainly one of the qualities that has encouraged us to continue exploring these fibres.
Stretch, Compression and Durability
Running tights and sports bras need to provide support, stretch repeatedly, recover their shape and withstand friction over time.
Polyester is particularly useful because of its strength, dimensional stability and abrasion resistance. When combined with elastane, it can create highly supportive fabrics with excellent stretch recovery.
TENCEL™ Lyocell is also a relatively strong cellulosic fibre, but it doesn't naturally provide the elastic recovery required for compression garments.
To achieve this, it also needs to be combined with elastane and enhanced using specialised knit structures. Garment construction, including seam placement, can also influence fit and support.
At REAL DREAM STATE®, this has been one of our biggest research and development challenges.
Finding the right combination of fabric density, knit structure and elastane for opacity, compression, stretch recovery and durability has taken considerable experimentation, all while relying on the least amount of elastane content possible.
One fabric we tested performed beautifully in several areas but showed signs of abrasion in high-friction zones. Its knit structure also created difficulties during manufacturing.
I've also experienced a pair of high-quality TENCEL™ blend leggings developing a hole around the gusset after approximately three years of wear.
It highlighted an important realisation: natural fibres degrade more quickly over time and ultimately won't be as long-lasting and durable as synthetics.
For us, wear testing is essential to see how our products not only perform but also endure repeated movement, washing and the passing of time.
Which Is Better for Your Skin?
The clear winner is TENCEL™ Lyocell.
Its smooth fibre surface, moisture-management and natural cooling properties make it beautiful to wear, without trapping heat, which polyester is notorious for.
The mechanic in which TENCEL™ Lyocell manages moisture also allows for less bacterial growth that can occur on your skins surface, which can cause rashes and also builds up odour.
So, Can TENCEL™ Replace Polyester in Running Clothes?
Potentially, and we're hopeful it can.
This optimism comes partly from my own experience testing TENCEL™ blend fabrics on runs of up to 11 kilometres.
So far, I've experienced amazing levels of comfort, support and performance.
But would these fabrics hold up over a marathon or ultramarathon? How would they perform after hundreds of kilometres and repeated washing?
These are questions we're still exploring, and I'm really excited to hear the honest feedback from runners participating in our wear-testing programme.
What interests us is whether natural-origin fibres can be pushed further through textile innovation to create sportswear that meets the demands of running while reducing our reliance on conventional synthetics all together.
A pair of leggings made from 85% TENCEL™ Lyocell and 15% conventional elastane still contains a synthetic component.
This is one of the challenges we're particularly interested in seeing how the industry innovates on.
There are currently developments in bio-based and alternative stretch fibres derived from nature that are looking promising.
The reality is that neither TENCEL™ Lyocell or polyester is without environmental impact. There will always be trade-offs, and it's about creating the best products we can with the resources available to us at the time.
For us, running remains the benchmark. It's repetitive, demanding and exposes weaknesses in fabric construction that might otherwise go unnoticed.
Our research is ongoing, and we believe there's still considerable room for innovation.
Follow our research and development journey as we continue exploring natural-fibre performance sportswear made for running and recovery.