January – time to get your sweat on. But if it’s a health kick you’re after, you may want to re-examine your wardrobe. A recent study by the University of Birmingham proved for the first time that PFAS – the forever chemicals building up in our environment with links to cancer, hormone disruption and low infant birth weight – can be absorbed from clothing through the skin. On top of that, the new, shorter chain PFAS the chemicals industry is switching to following bans on longer chain fluorocarbons, are more effective at crossing the skin barrier.

For sportswear, this raises flags. PFAS are present in many of the dyes and invisible finishes we expect of performance materials. Sportswear is often tight, we sweat in it, creating better conditions for osmosis, and the abrasive nature of workouts means the textiles rub against the skin. But when it comes to performance wear, those great synthetic textile revolutions of the 20th century – waterproof Goretex, stretchy Lycra and Spandex, ‘odour, sweat resistant’ nylons – still win out. No one wants a sports bra without support, or a running vest you can’t sweat in. So what are the options?

There are twin evils when it comes to synthetic materials – the microplastics that these textiles shed, which we know are building up everywhere from the Arctic ice sheet to your mother’s placenta, and the chemical dyes and finishes that are used to increase their performance. “The cheaper the product, the cheaper the chemistry, and that’s where you have concerns about toxicity,” says Matthias Foessel, of Beyond Surface Technologies. Consumers have two options – going natural and regenerative, or sticking around for cleaner, alternative biomaterials.

Let’s take the latter first – Nanoloom is one of the great hopes to replace the stretch we expect from Lycra and Spandex. Created out of the Nobel prize winning graphene discovery, Nanoloom claims to have a bonding process that allows a high percentage of graphene to be incorporated into yarn. With exceptional moisture wicking, water resistance, durability and stretch, Nanoloom is a non toxic, biodegradable alternative to Elastene. “Stretch and recovery is 100%” says co-founder Victoria Mataczynski, triumphant from a recent trial with Gymshark. The company begins commercial production next year and presents a PFAs free solution to the industry. But competition is tough: “Elastene was innovated in the 70s, so we’re expected to meet a similar standard of production and performance as something that’s been around for decades – and is super cheap.”

“Some of the new bio-based materials coming to market now are simply better: they outperform legacy (fossil fuel based) materials, they’re cheaper at scale, they’re non toxic, and they’re carbon-negative,” says Nic Gorini, of venture capital firm, Spin Ventures. “Awareness of toxicity of existing materials is going to be a big driver in their uptake in the next decade.”

Green chemistry pioneers Beyond Surface Technologies have two 100% plant-based water repellency products coming out this year. They also have two 100% biocarbon based moisture wicking finishes already in market: “They are state of the art,” says Foessel, “with performance and durability equal to petroleum finishes,” name checking Patagonia, Lululemon, adidas, PUMA and Fabletics, as brands trialling their cleaner approach.

While we wait to see if these materials will reach scale, your current best option is to go natural. Don’t be fooled by the ‘benefits’ of recycled polyester – a recent Changing Markets study found recycled polyester sheds more microplastics than virgin. “We are oversold the benefits of specialist performance wear,” says Ed Brial, founder of regenerative cotton solution, Materra, now used by Mango and Ecoalf. “You can go for a run in t-shirt and joggers.” Cotton absorbs water “and can be quite heavy if not woven in the right way, but it doesn’t pick up smells like plastics do, is durable and biodegradable.” Community Clothing’s Patrick Grant agrees: “The men’s 100m record before synthetics stood at 9.95 seconds. Only very few people have run faster. Synthetic sports clothing gives only a slight performance edge.” Grant has developed Community Clothing Organic, a 100% natural, biodegradable sportswear collection, from waistband to stitching thread. Five years of innovation has produced lightweight, fast-drying cotton fabrics, a woven natural rubber and cotton elastic. What’s more it’s affordable – from £30 for a racer back vest.

Less affordable is merino sportswear, but undoubtedly wool offers incredible benefits in terms of thermo regulation, as well as superior technical advances in weaving, enabling brands like Icebreaker to achieve a 97% merino wool collection. Even more impressive is Mover, a mountaineering company whose range of Ventile cotton and 100% wool outerwear promise superior performance in extreme conditions.

Brands like Pangaia and BAM offer semi-synthetics in the form of bamboo and corn, which derive their polymers from natural sources, not petrochemicals. Any polymer-based fibre will shed microfibres through wear and washing, but “the important question is what happens to the particles: if a material is biodegradable or compostable, shed fibres can break down under the right environmental conditions,” say Pangaia, whose 365 Seamless Activewear collection is PFAS-free, and certified under OEKO-TEX® STANDARD 100. If you are looking for a good stretch legging and sports bra, they offer better options than anything petrochemical derived, and what’s more are finished with the brand’s trademark natural PPRMINT™ oil for odour resistance. 

When it comes to footwear, the matrix gets more complicated. Shoes often contain up to 20 component parts, and durability is the priority. No one wants a mushroom leather running shoe that falls apart in a few months. At barefoot health brand Vivobarefoot, durability is the priority. “With all the effort and resources it takes putting shoes together, they need to last a long time,” says Charlotte Pumford, Vivobarefoot’s sustainability lead. Instead, shoes are designed for disassembly and repair.

That said, the company is constantly trialling new materials, working with NFW’s natural rubber Pliant and leather alternatives Mirum and Hyphalite, as well as algae derived leather alternative, Algenesis. But until those biomaterials compete on durability, recycled polyester wins. “Everything is tested robustly against European and California specific legislation, which is pretty strict,” says Pumford, “although we go beyond just legal limits.” Prioritising foot health and limiting impact is a constant balance: “Our mission is to reconnect people back to nature: we enable feet to biomechanically do what they are meant to do.” Professional athletes, personal trainers and fitness experts agree, and while there are now over 90 barefoot brands following in Vivo’s wake, “using less certified and cheaper materials, we remain stoic in our mission.”

“People do not react well to wearing shoddy plastic on our bodies. We should be worried and concerned,” says Brial, “for human health, planetary health, and the health of workers.”

“Polyester took 50 years to get there, with a really big oil lobby behind them and lots of evil marketing to get people to use it,” says Vivo design consultant Aisha Kuijk. “We have to form a rebellion – our own lobby – to push it through. We have something to fight for!”

Tiffanie is an author, activist and founder of the Rule of Five campaign and the sustainable luxury concept @agora-ibiza. You can read more of her work on Substack at It’s Not Sustainable