Bio-based activewear fabrics offer brands a way to replace some fossil-derived raw materials while retaining the performance their products require. However, a bio-based label alone does not tell you how a fabric will stretch, recover, withstand washing or perform in a finished garment.
For activewear brands developing leggings, sports bras, training tops and shorts, the practical questions are straightforward: What is the material made from? How much of it is bio-based? Can the supplier document that claim? And will the fabric meet your quality, cost and production requirements?
This guide explains the key material options and the checks to complete before moving from fabric selection to bulk production.
This guide explains the key material options and the checks to complete before moving from fabric selection to bulk production.
Why Bio-Based Materials Matter for Activewear
Polyester remains central to the textile industry. According to Textile Exchange, it accounted for 59% of global fiber production in 2025, with production reaching approximately 82.5 million tonnes. These figures cover all fiber end uses, not activewear alone.
For brands that use synthetic performance fabrics, changing the raw material source may be one option alongside recycled materials and other design improvements.
Bio-based development does not necessarily mean replacing engineered fibers with cotton or other natural fibers. It can involve making synthetic polymers using partly or wholly biomass-derived ingredients.
That distinction matters: a material can have a renewable biological origin and still be a synthetic fiber.
What Does “Bio-Based Fabric” Actually Mean?
A bio-based material is made partly or entirely from biomass, such as plant-derived feedstocks. The term describes its origin, rather than guaranteeing a particular environmental outcome or disposal route.
Before comparing fabric options, distinguish these terms:
| Term | Meaning | What brands should check |
| Bio-based | Made partly or wholly from biomass | The oercebtage, measurement basis and component covered |
| Biosynthetic | A synthetic material made using biological feedstocks | The polymer type and documented bio-based content |
| Biodegradable | Capable of biological breakdown under specified conditions | Test conditions, timeframe and applicability to the finished product |
| Renewable carbon | A broader concept covering biomass, recycled carbon and captured CO₂ | Which source and production route are involved |
| Mass balance | A chain-of-custody approach that allocates certified to outputs through accounting | Certification scope and permitted product claims |
Renewable carbon is broader than bio-based carbon. A material made using recycled fossil-derived carbon or captured CO₂ is not automatically bio-based.
Similarly, bio-based does not mean biodegradable. A fully bio-based polymer may be non-biodegradable, while some fossil-derived polymers can biodegrade under suitable conditions.
Bio-Based Material Options to Discuss With Your Fabric Supplier
Material names are a starting point. A commercially available polymer does not automatically mean that a suitable fabric is available in your required construction, color, quantity or leand time.
Bio-Based Polyester
Partially bio-based PET can replace a portion of conventional PET’s feedstock with biomass-derived ingredients. Research has examined both partially and fully bio-based PET pathways, including the environmental trade-offs associated with different feedstocks.
If a supplier offers “bio-polyester, ” ask for the exact polymer, bio-based percentage and supporting documentation. Do not assume that all bio-based polyester products have the same composition.
For running tops or base layers, compare the proposed fabric against your existing specification for weight, drying performance, hand feel and wash stability.
Bio-Based Elastane
Bio-derived ingredients are also being developed for stretch fibers. The LYCRA Compant has described a route using QIRA® bio-derived feedstock intended to give LYCRA® fiber 70% renewable content. That figure concerns the fiber — not an entire garment made with that fiber.
The distinction can materially change a product claim.
For example, if a fabric contains 20% elastane and that elastane has 70% bio-based content on a compatible mass basis, the elastane would contribute 14% of the fabric’s mass as bio-based content. This is an illustrative calculation; it should not replace supplier documentation or testing.
For leggings and sports bras, request evidence of stretch recovery and performance after repeated washing, alongside the content information.
Bio-Based Nylon
“Bio-based nylon” describes more than one material.
Arkema’s Rilsan® PA11, for example, is made from castor oil and is identified by the producer as a polymer of 100% renewable origin. PA11 is a different polymer from conventional PA6 or PA66, so it should not be treated as an interchangeable substitute without validation.
Ask the mill to identify the nylon grade and confirm the finished fabric’s suitability for your application. For swimwear, that assessment should include exposure to chlorine and saltwater; for fitted activewear, focus on recovery, abrasion and opacity.
Bio-Based EVA for Footwear
For brands expanding into footwear, bio-based EVA provides an example of an established application. Braskem documents the use of sugarcane-derived EVA in commercial footwear, including an Allbirds collaboration.
This does not establish suitability for an apparel fabric. It illustrates why bio-based materials should be evaluated by specific application rather than as a single category.
How to Evaluate Performance in the Finished Fabric
A feedstock claim and a performance claim require different evidence.
Start with the intended garment and establish acceptance criteria before selecting a material. The following is a suggested development checklist:
| Product category | Priority checks |
| Leggings and biker shorts | Stretch recovery, opacity during movement, pilling, seam strength and wash stability |
| Sports bras | Recovery, fabric growth, support in the finished construction, perspiration colorfastness and repeated-wash performance |
| Running tops and base layers | Fabric weight, moisture management, drying performance, breathability and dimensional stability |
| Training shorts | Abrasion resistance, mobility, seam performance and colorfastness |
| Swimwear | Chlorine and saltwater resistance, recovery, colorfastness and durability |
Agree on the test method, conditioning, wash procedure and pass criteria with your supplier. Two reports using different methods may not be directly comparable.
Include garment trials as well as fabric tests. A material that performs well as a swatch still needs to work with your pattern, seams, trims and intended fit.
What Mass Balance Certification Does — and Does Not — Show
Mass balance allows certified and conventional inputs to be processed within a shared system, with certified quantities tracked and allocated through verified accounting.
ISCC distinguishes this from physical segregation and controlled blending. Under mass balance, an allocation should not be presented as proof that finished product physicall contains that exact percentage of certified material.
When reviewing a supplier’s documentation, ask:
- Which company, site and material does the certification cover?
- Which chain-of-custody model applies?
- Is the claim about physical content or allocated inputs?
- What supporting documents relate to your purchase?
- What wording is permitted for your product communication?
ISCC’s claims guidance specifically requires mass-balance statements to communicate the sourcing relationship without implying exact physical content.
Questions to Ask Before Approving Bulk Production
A fabric can be promising at the sample stage while remaining unsuitable for your order requirements. Use a written sourcing checklist to make the comparison concrete.
- What is the complete fiber composition?
Request the percentages of every fiber in the finished fabric. - What does the bio-based percentage refer to?
Clarify whether it describes a feedstock, polymer, fiber, fabric or finished garment. - How is that percentage established?
Ask whether it is measured physical content or a certified allocation. - What are the fabric specifications?
Confirm GSM, usable width, construction, finish, stretch and recovery. - Which tests are available?
Check that reports apply to the proposed fabric and relevant color or finish. - What are the commercial requirements?
Confirm price, minimum order quantity, sampling time and bulk lead time. - Can the material be supplied consistently?
Discuss repeat orders, batch variation and change-control procedures. - What environmental evidence supports the claims?
If reduced impact is claimed, request the comparison baseline, assessment boundaries and supporting data. - What happens at end of life?
Ask about a practical collection and recycling route for the finished blend, rather than relying on a general statement about the polymer.
A Practical Route From Sample to Production
For a first project, consider trialing one fabric in one product category. This makes it easier to compare results against an existing specification.
A useful sequence is:
Define requirements → review supplier evidence → assess swatches → make samples → test performance and fit → approve production specifications.
Keep material claims and garment approvals in the same development record. Record what was tested, which documents were reviewed and which version of the fabric was approved.
If a supplier changes the yarn, finish or construction, review whether further testing is needed before accepting the change.
Frequently Asked Questions
Are bio-based activewear fabrics plastic-free?
Not necessarily. Bio-based polyester, nylon and elastane are still synthetic polymers. “Bio-based” describes the raw material origin; it does not automatically mean plastic-free.
Are bio-based fabrics always better for the environment?
The label alone is not enough to establish that. Assessment should consider the specific feedstock and production route, along with energy use and other life-cycle impacts. Research on bio-based PET shows why results need to be evaluated by scenario rather than assumed from the name.
Can a fabric with bio-based elastane be called 100% bio-based?
Only if evidence supports that claim for the entire fabric. A bio-based percentage for one fiber cannot automatically be applied to the other components in the blend.
What should a brand request first?
Start with the fabric specification, documented content claim, relevant test reports and a swatch. Then confirm pricing, minimum quantities and availability before committing to garment development.
Planning Your Next Activewear Collection?
Share your product references, target fabric weight, composition preferences and performance requirements with CozyActive to discuss your project.
For any proposed bio-based option, confirm material availability, supporting documentation and sampling requirements before approving it for your collection.
