Cellulosic Fibres Reshape the Future of Sportswear

Sportswear companies are reassessing the materials used in activewear and outdoor clothing as scrutiny of fossil-based synthetic fibres intensifies.

Polyester, nylon and elastane remain central to performance apparel because they offer durability, stretch, rapid drying and relatively low production costs. However, concerns about microfibre pollution, carbon emissions, chemical treatments and end-of-life waste are encouraging brands to investigate a broader range of materials.

Among the alternatives gaining attention are natural and man-made cellulosic fibres, including cotton, lyocell, modal and viscose. Wool and fibres regenerated from discarded textiles are also becoming part of a more diversified materials strategy.

The transition is not a simple replacement of synthetic fabrics. Instead, the industry is trying to determine where cellulosic fibres can meet technical requirements, where blends remain necessary and how environmental benefits should be measured.

Why sportswear brands are reconsidering synthetics

Synthetic fibres have shaped modern sportswear because their properties can be engineered for demanding applications. They can be lightweight, elastic, abrasion-resistant and capable of moving moisture away from the skin.

Their drawbacks are increasingly difficult to ignore.

Most conventional synthetic fibres are derived from fossil resources. They may also release microscopic plastic fibres during manufacturing, use and washing. Textile products are recognised as an important source of microplastic pollution in Europe, strengthening calls for pollution to be addressed through product design as well as filtration and waste management.

European policy is also moving towards stronger requirements concerning durability, environmental claims, textile waste, product information and producer responsibility. These developments are giving apparel businesses an additional reason to understand their fibre supply chains and document the environmental characteristics of their products.

The result is not the immediate disappearance of polyester or nylon. It is a more critical assessment of when these fibres are genuinely necessary and when renewable or regenerated materials could perform the same function.

What cellulosic fibres bring to performance clothing

Cellulosic fibres are based on cellulose, the structural material found in plants.

Natural cellulosic fibres such as cotton are obtained directly from plants. Man-made cellulosic fibres, commonly known as MMCFs, are produced by dissolving cellulose—usually sourced from wood pulp—and regenerating it into fibres. Viscose, modal and lyocell all belong to this group.

These materials can offer characteristics that are valuable in sportswear:

• softness against the skin;

• breathability;

• moisture absorption;

• temperature comfort;

• reduced accumulation of odours in certain constructions;

• a renewable feedstock when responsibly sourced.

These qualities make cellulosic fibres particularly relevant to base layers, yoga clothing, leisurewear, training tops and other garments worn close to the body.

Recent industry analysis indicates that performance apparel companies are expanding their definition of performance. Speed of drying and mechanical strength still matter, but comfort, odour management, material origin and environmental responsibility are becoming more important purchasing criteria.

Cotton is being engineered beyond casualwear

Cotton is comfortable and familiar, but conventional cotton fabrics tend to absorb and retain moisture. That can make them feel heavy during intense exercise and slower to dry than polyester.

Textile engineering is helping to reduce those limitations.

Yarn structure, fabric construction, surface treatments and carefully designed blends can improve moisture transport. Manufacturers can also position fibres within a fabric so that moisture is drawn away from the skin while retaining cotton’s softness.

These developments do not make every cotton fabric suitable for endurance running or extreme outdoor conditions. They do, however, expand cotton’s role in lower- and medium-intensity sportswear, where comfort may be as important as drying speed.

Lyocell and modal move closer to technical applications

Lyocell and modal are increasingly visible in activewear because of their smooth handle, breathability and moisture-management potential.

Lyocell is especially attractive for garments worn next to the skin. Its performance can be adjusted through yarn engineering, fabric structure and blending with other fibres. Commercial fibre systems such as Tencel have helped position lyocell beyond fashion basics and into technical clothing.

Research into moisture-regulating viscose-based fabrics also suggests that regenerated cellulosic fibres can be modified for activewear applications, although the environmental impact of any additional finish must be considered alongside its performance benefits.

The principal challenge is balancing comfort with durability, elasticity and drying time. A soft, absorbent fabric may perform well in a yoga top but be less appropriate for a compression garment, waterproof shell or high-abrasion trail-running product.

Merino wool remains important in outdoor clothing

Merino wool occupies a distinct position in the materials transition.

It is valued in outdoor and activewear for thermal regulation, moisture buffering and natural resistance to odour build-up. These properties make it useful in base layers, socks and garments intended for repeated wear.

Wool is not a cellulosic fibre, but it is frequently considered alongside cellulosic alternatives because it can reduce the need for fully synthetic, next-to-skin products.

As with every material, its environmental profile depends on factors such as farming practices, processing, durability, garment care and traceability. “Natural” should not automatically be treated as a guarantee of low impact.

Regenerated fibres could reduce pressure on virgin resources

Some of the most significant developments involve cellulose recovered from textile waste rather than obtained exclusively from virgin wood or crops.

Companies are developing processes that transform cotton-rich discarded clothing, agricultural residues and other cellulose-containing waste into new fibre feedstocks. This could help reduce demand for virgin raw materials while creating higher-value uses for textile waste.

Circulose, for example, is made from recycled cotton-rich material and is designed to replace part of the virgin pulp used in regenerated cellulosic fibre production. Other developers are exploring different mechanical, chemical and hybrid processes.

The potential is considerable, but commercialisation remains difficult. Recycling technologies need reliable waste collection, accurate fibre sorting, contamination control, investment in production capacity and long-term purchasing commitments from brands.

A technically successful fibre will not necessarily reach scale unless the surrounding supply chain is economically viable.

Cellulosic does not automatically mean sustainable

The environmental case for MMCFs requires careful qualification.

Wood-based fibres can be renewable, but poor sourcing practices may contribute to deforestation, habitat loss or pressure on ancient and endangered forests. Responsible procurement therefore requires traceable pulp and credible forest-management safeguards.

The manufacturing process also matters. Producing regenerated fibres involves dissolving cellulose and reforming it into filaments. Chemical recovery rates, energy sources, water use and emissions can vary substantially between processes and factories.

Industry assessments identify greenhouse gas emissions, water consumption, energy use, chemical management, land-use change and recyclability as important indicators when evaluating MMCF production.

Biodegradability must also be described carefully. A cellulose-based fibre may biodegrade under suitable conditions, but the behaviour of a finished garment can be altered by dyes, coatings, synthetic stitching, elastane, membranes and other components.

A blended sportswear product should not be presented as biodegradable merely because it contains lyocell or cotton.

Why blended fabrics will remain common

For many performance products, the immediate future is likely to be hybrid rather than entirely plastic-free.

A manufacturer might combine lyocell with recycled polyester to improve drying and durability, or add a small amount of elastane to achieve stretch and recovery. Wool may be blended with synthetic fibres to strengthen a lightweight base layer.

These combinations can extend product life and improve usability. However, they can also make fibre-to-fibre recycling more complicated.

Brands therefore face a design trade-off: adding several materials may improve performance during use but create a more difficult product to separate and recycle at the end of its life.

The most credible approach is to evaluate the complete product rather than promote one preferred fibre in isolation.

Performance standards remain the decisive test

Cellulosic fibres will gain market share only where they can satisfy the intended use of the garment.

A training shirt, ski base layer and waterproof mountaineering jacket have very different technical requirements. Material selection must account for factors such as:

• drying time;

• moisture transport;

• wet strength;

• abrasion resistance;

• stretch and recovery;

• thermal regulation;

• dimensional stability;

• wash durability;

• fibre shedding;

• repairability and recyclability.

This product-specific approach is more useful than claiming that one material is universally superior.

For extreme applications, synthetic fibres may remain difficult to replace. In less demanding garments, cellulosic and natural fibres may already offer a strong combination of comfort and adequate performance.  cellulosic fibres sportswear

What the shift means for the sportswear industry

The growth of cellulosic fibres signals a broader change in how performance apparel is designed.

Brands are being pushed to consider not only how a garment functions during exercise, but also where its raw materials come from, which chemicals are used, how long it remains wearable and what happens after disposal.

This transition will require closer collaboration among fibre producers, mills, chemical suppliers, garment manufacturers, recyclers and sportswear companies.

It will also require more precise environmental communication. Claims such as “natural,” “plant-based” or “biodegradable” provide little useful information without evidence about sourcing, processing, product composition and disposal conditions.

Cellulosic fibres will not eliminate the sportswear industry’s dependence on synthetics in the near term. Their growing use nevertheless shows that comfort, renewable feedstocks and circular material systems are becoming part of the technical performance brief.

The strongest products are likely to be those that use each fibre deliberately, minimise unnecessary material complexity and support environmental claims with traceable data.

Frequently asked questions

What are man-made cellulosic fibres?

Man-made cellulosic fibres are regenerated fibres produced from dissolved cellulose, usually sourced from wood pulp. Common examples include viscose, modal and lyocell.

Why are cellulosic fibres being used in sportswear?

They can provide softness, breathability, moisture absorption and next-to-skin comfort. Fibre engineering and fabric construction are also improving their suitability for selected performance applications.

Are cellulosic fibres biodegradable?

Some unmodified cellulosic fibres can biodegrade under suitable conditions. A finished garment may behave differently because of dyes, chemical finishes, synthetic blends, coatings, threads and accessories.

Can cellulosic fibres replace polyester?

They can replace polyester in some garments, particularly products prioritising comfort and breathability. Polyester, nylon and elastane still offer advantages in applications requiring rapid drying, high elasticity or exceptional durability.

Are all MMCFs environmentally sustainable?

No. Their impact depends on forest sourcing, feedstock type, chemical management, energy use, water consumption, production efficiency and the durability and end-of-life treatment of the finished garment.

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