Polyester vs nylon for activewear: which fabric to choose

For most activewear, the choice comes down to what the garment must do. Polyester absorbs very little water, is by far the most widely produced fibre, has a large recycled supply, and is the fibre that dye sublimation printing is built on, so it suits printed team kit, running tops and budget ranges. Nylon (polyamide) holds more moisture, and its producers promote a softer handle and better abrasion resistance, which is why buyers often shortlist it for premium leggings and sports bras. Both depend on elastane for stretch. Decide on the fabric construction and test results, not the fibre name alone.

What polyester and nylon actually are

Both are synthetic fibres made from long-chain polymers, but different ones. EU Regulation (EU) No 1007/2011 defines polyester as a fibre with at least 85% by mass of an ester of a diol and terephthalic acid in its chain, and lists “polyamide or nylon” as a single fibre name built on amide linkages. Elastane, the stretch fibre in almost every legging, is defined as at least 85% segmented polyurethane that recovers rapidly after being stretched to three times its length.

In the US, the Federal Trade Commission’s textile rules use the generic names polyester, nylon and spandex. Its labelling guide confirms that the ISO names polyamide and elastane may also be used. So a US label can read “78% nylon, 22% spandex” or “78% polyamide, 22% elastane”; an EU label uses the EU names.

Fibre brands follow the same logic. The FTC allows a fibre trade mark on a content label only when it appears next to the generic name, in lettering of equal size and prominence, and a trade mark must not suggest a product is made entirely of a fibre when it is not. If your leggings use a branded elastane or a branded recycled yarn, the label still has to state the generic fibre and its percentage, and you should hold the yarn supplier’s paperwork for the brand.

The scale is very different. Textile Exchange’s Materials Market Report 2026 puts polyester at about 82.5 million tonnes in 2025, some 59% of all fibre produced. Polyamide was about 7.3 million tonnes, roughly 5%, and elastane about 1.6 million tonnes. That gap matters for price, choice of fabrics and recycled supply.

Polyester vs nylon at a glance

Sources: Regulation (EU) 1007/2011 Annexes I and IX; FTC; Textile Exchange Materials Market Report 2026; Cotton Incorporated; Fulgar; University of Alberta (2024). The moisture figures are the conventional allowances the EU uses to calculate fibre content, not measured sweat absorption.

Feel, stretch and fit

Stretch in activewear comes from elastane, not from either base fibre. A typical legging fabric pairs nylon or polyester with a percentage of elastane, and the elastane content, yarn count and knit structure decide compression, recovery and whether the fabric turns see-through when stretched.

Where the two differ is in the base yarn’s handle. Fulgar, an Italian polyamide yarn producer, describes polyamide as softer and more elastic, and polyester as drier and stiffer to the touch. Treat that as a producer’s view, because modern polyester microfibres and brushed finishes change the feel a great deal. The honest test is to compare swatches of the actual fabrics at the same weight and elastane content, stretched over a hand, and to make a fit sample in each before deciding.

Always specify the fabric by composition, weight in GSM, construction and elastane percentage. A request for “nylon spandex, buttery feel” will be quoted in ten different fabrics.

Moisture, sweat and drying

Polyester is strongly hydrophobic. The EU’s agreed moisture allowance, used by labs to calculate fibre content, is 1.5% for polyester against 6.25% for polyamide staple fibre and 5.75% for filament. Fulgar gives polyamide a moisture regain of about 4% and describes polyester as near zero.

What that means on the body depends on how you read it. A fibre that absorbs little water leaves sweat on the surface, where the fabric structure and any wicking finish must move it away. A fibre that holds a little more moisture can feel less clammy against the skin but may take longer to dry. In practice, knit construction and finish usually matter more than the fibre: a two-layer knit with a finer yarn on the inside moves sweat outward whichever polymer it uses.

If moisture management is a selling point, ask the mill for a test report on the finished fabric to a named method, and do not copy a fibre producer’s claim onto your product page without one.

Durability: abrasion and pilling

Leggings wear out first at the inner thigh and seat, where fabric rubs against itself and against gym equipment. Polyamide producers promote nylon’s abrasion resistance for exactly this reason, and Fulgar describes polyester as performing less well under prolonged friction.

That is a claim about fibres, not about your fabric. Yarn type, filament count, knit density and finishing change abrasion and pilling results more than the polymer does. The way to settle it is to test. ISO 12947-2 measures abrasion resistance by the Martindale method: a circular specimen under a defined load is rubbed against a standard abrasive fabric in a Lissajous pattern, and inspected at fixed intervals until it breaks down. Ask for Martindale and pilling results on the finished fabric of each candidate, and set a minimum in your specification.

Wear-test fit samples too. A week of real training shows problems a lab cannot, such as seams that chafe or a waistband that rolls.

Odour: which smells less after training?

On odour, the published research leans against polyester. In a 2014 Ghent University study published in Applied and Environmental Microbiology, T-shirts from 26 people were collected after an hour of intensive indoor cycling and left for 28 hours. A trained odour panel found the polyester shirts smelled significantly less pleasant and more intense than the cotton ones, and micrococci were found almost only on the synthetic shirts.

Nylon was compared directly in a 2024 University of Alberta study in Textile Research Journal, which soaked fibres in a simulated sweat solution and measured the odorants they released into the air. Polyester, nylon and wool initially released more odorants than cotton and viscose. But nylon and wool let them go more quickly: after 24 hours they gave off much lower intensities than polyester, closer to the cellulosic fibres. The researchers suggested that polyester garments still need washing, while nylon and wool ones might be freshened by airing.

These are one small wear panel and one laboratory method. Neither tested finished leggings, and neither looked at anti-odour yarns or finishes, so treat odour as a reason to wear-test, not a verdict. Before an odour claim goes on a product page, ask for the finish supplier’s test evidence.

Colour and printing: why sublimation needs polyester

This is the clearest difference between the two fibres. Sublimation printing uses disperse dyes. Cotton Incorporated’s technical bulletin on printing explains that disperse dyes are solids that turn into a gas at elevated temperature without passing through a liquid stage, and that this sublimation is the means by which the dye disperses into the polyester fibre. Polyester is the fibre the process is designed around, so all-over printed kit, from football shirts to cycling jerseys, is normally made in polyester.

Nylon is not the normal base for sublimation. If your design needs an all-over print on a nylon fabric, ask for a strike-off and a wash and rubbing fastness test before committing, or choose another print method. Our sublimation method page explains the process and the fabric requirements.

For solid colours, both fibres can be dyed to deep, even shades, but the dyeing conditions differ. Fulgar notes that polyester needs high temperatures and pressures to dye consistently. Whichever fibre you choose, approve colour on a lab dip made on the real fabric, not a colour card, and ask for colour fastness results on the bulk lot.

Recycled polyester and recycled nylon: what the certificates mean

Recycled supply is much larger for polyester. Textile Exchange reports recycled polyester at around 12% of polyester production in 2025, with about 97% of it made from plastic bottles. Recycled polyamide was about 3% of polyamide, held back by technical recycling challenges and the comparatively low price of virgin polyamide. Most recycled polyamide comes from pre-consumer waste or post-consumer materials such as discarded fishing nets and carpets.

A recycled claim needs a certificate chain, not a swing-tag word. Textile Exchange runs the Global Recycled Standard (GRS) and the Recycled Claim Standard (RCS). It explains that the GRS can be used business to business for products with at least 20% recycled content, but consumer-facing labelling requires at least 50% recycled content, and the GRS adds social, environmental and chemical requirements that the RCS does not. Textile Exchange is also moving its standards into a new Materials Matter Standard, so check which version a supplier is certified to.

• Ask each supplier in the chain for its scope certificate, and ask for a transaction certificate for your shipment.
• Check that the recycled percentage on the label matches the certified content.
• Remember that “recycled from bottles” is not textile-to-textile recycling; say which it is.

Our sustainable clothing manufacturing page covers which certificates a claim needs before it is printed.

Price and availability

We do not publish fabric prices here because they move with oil, yarn markets and order size. What is certain is the difference in scale: polyester is produced at roughly eleven times the volume of polyamide, so there are more mills, more stock fabrics and more recycled options to choose from. For a first collection, that wider choice is a practical advantage when you need a fabric that already exists rather than one knitted to order.

The fair way to compare is to ask for quotes on both fibres in the same construction, weight and elastane content, with the same test requirements attached. The cost estimator splits a quoted price into fabric, trims and making, so you can see how much of it the fabric is.

Which fabric for which activewear product?

• Printed team kit, running and training tops: polyester, usually sublimated. See team kit manufacturing.
• Premium leggings and sports bras: nylon with elastane is the common choice where handle and rub resistance lead the brief; polyester with elastane is a sound option where price, print or recycled content lead.
• Shorts and outer layers: either, chosen on weight, weave or knit, and finish.
• Small first drops: our sister company, Collective Studio Ltd. (our co-founder Homaira Jashim co-founded it and AB Rahman is its Head of Growth), has a small-run activewear route from 150 pieces per style and colour.

Our activewear manufacturing page shows the product range. To compare the two fibres on your own design, send us your tech pack and ask for both options.