1st October 2026 – (Hong Kong) Spend a few minutes in an upscale activewear store and watch what shoppers do. They feel the fabric, check the colour in the mirror and look at the price. Hardly anyone turns the garment inside out to read the small label in the seam. That label tells a story the shop would prefer you didn’t read.
An Instagram creator who posts as Anastasia did read it. In a recent reel, she walked into an Alo store to check prices and fabric labels. Then she asked when we decided it was normal to work out in polyester, nylon and other synthetics. People exercised without plastic clothing for most of history. Synthetics are everywhere now, she argued, “because we stopped paying attention.”
Polyester is polyethylene terephthalate, the same plastic used in drinks bottles, and it’s made from petroleum. It doesn’t biodegrade. Every wash and every wear sheds tiny fibres. The European Environment Agency estimates that 200,000 to 500,000 tonnes of microplastics from textiles reach the world’s oceans each year.
The industry’s favourite answer is recycled polyester, and at first the case looks strong. Reusing plastic cuts demand for new oil, and some estimates put the emissions saving in production at up to 50%. When a garment really needs a synthetic, recycled is usually better than virgin.
Look longer, though, and the picture gets murkier. Textile Exchange data shows that about 98% of recycled polyester comes from PET bottles, not old clothes. Fibre made from recycled textiles is still less than 1% of the global market. A bottle can become another bottle many times over. Once it’s spun into leggings blended with elastane, that cycle generally ends. The bottle wasn’t rescued from the sea. It was taken out of a recycling system that already worked and turned into a product that will probably end up in landfill. Recycled polyester isn’t even gaining ground. Its market share fell from 12.5% to 12% because virgin polyester grew faster.
In December 2025, the Changing Markets Foundation published tests by microplastics researchers at Çukurova University in Turkey. They washed 51 garments from Adidas, H&M, Nike, Shein and Zara. On average, recycled polyester released about 12,430 fibres per gram. That’s roughly 55% more than the 8,028 released by virgin polyester. The recycled fibres were also shorter, averaging 0.42mm against 0.52mm. Smaller fibres travel further and are easier for living things to swallow or breathe in.
When the work appeared in a peer-reviewed journal, the authors said the gap in fibre counts wasn’t statistically significant because results varied widely between garments. The difference in fibre length was significant. An industry-backed study from 2023 found that mechanically recycled polyester shed no more than virgin. A separate peer-reviewed study in 2025 found something more worrying. Fabric recycled once shed about the same as virgin polyester. Fabric recycled twice shed about 4.3 times more, and fabric recycled three times shed about 6.2 times more. Each round of recycling weakens the fibre.
So the honest conclusion isn’t that recycled polyester is always worse. It’s that “recycled” doesn’t mean “safe” or “sustainable,” and the industry claims more than the evidence supports. The Remake 2024 accountability report found that none of the companies it assessed both sourced recycled polyester transparently and phased out materials that can’t be recycled back into textiles.
Which brings us to Alo.
Alo’s best-known performance fabric, Airlift, is about 82% polyester and 18% elastane. Airbrush is a blend of nylon and spandex. These fabrics give the glossy, sculpted look that celebrities wear from the studio to brunch. But synthetics are cheap to make at scale, which makes luxury prices harder to justify. Reviews on Trustpilot and Reddit include complaints about pilling after only a few wears. Testers at OutdoorGearLab found the Airbrush leggings ran hot during vigorous classes.
The fabric is only part of the problem. The ethics-rating platform Good On You rated Alo “We Avoid” in 2022. Its December 2025 update moves the brand up one step to “Not Good Enough.” Alo still scores one out of five for its impact on the planet and one out of five for people, with workers’ rights rated “Very Poor.” Good On You has said it found no evidence that Alo pays a living wage in its supply chain or takes meaningful action on emissions and textile waste. Alo points to a solar-powered office and electric-car chargers. Those help, but a clothing brand does most of its damage in its supply chain.
Yoga teaches ahimsa, the principle of doing no harm. A brand that sells the language of mindfulness should be held to it. Alo has added modal and other plant-based fibres for gentler workouts, which shows it can change when it wants to.
You don’t have to abandon synthetics entirely—swimwear and some high‑intensity kit still rely on them—but get the priorities straight: buy less, keep garments in rotation for longer, opt for second‑hand when you can and treat recycling as the final step. For lower‑impact sessions, pick cotton, Tencel, merino or hemp. When you do use synthetics, wash them less frequently, choose cooler cycles and run full loads.
Most of all, do what Anastasia did and read the label. Brands are counting on you not to.
