5 Reasons To Ditch Polyester

What clinical research reveals about the health risks of synthetic activewear

1. Scientists Are Finding Microplastics In Our Organs

Synthetic fabrics like polyester shed microplastic fibers during movement. Every rep, stretch, movement releases thousands of particles into the air.

When you exercise, your breathing rate increases 10-20x. Microplastics that shed from your sports clothes are inhaled during that time.

Scientists have detected microplastics in:

  • Brain (Nihart et al., Nature Medicine 2025)
  • Reproductive organs (2023-2024 studies)
  • Blood (Leslie et al., 2022)
  • Lungs (Jenner et al., 2022)
  • Placenta (Ragusa et al., 2021))

These plastic particles don't just sit there - they cause real damage

Research already shows multiple health risks:

Reproductive health: Microplastics have been found in all testicle samples analyzed (2024). Studies link these particles to decreased sperm mobility and disrupted testosterone pathways.

Cardiovascular risk: New England Journal of Medicine tracked 257 patients post-surgery. Those with microplastics in artery plaques had 4.5x higher risk of heart attack, stroke, or death within 34 months.

Respiratory risk: Textile workers exposed to synthetic fibers show higher rates of interstitial lung disease and chronic respiratory symptoms.

Other studies show microplastics trigger inflammatory pathways (Feng et al., 2023), oxidative stress (Kadac-Czapska et al., 2024), barrier disruption in gut, blood-brain, placental tissues (multiple studies 2022-2024), and metabolic dysfunction (Schwabl et al., 2019; Yan et al., 2022).

2. Your Gym Clothes Are Soaking You in Forever Chemicals and Heavy Metals

Most polyester activewear is treated with PFAS finishes for a 'sweat-beading' effect.

The health risks? Higher PFAS exposure correlates with:

  • Weakened immune response to vaccines (NCBI, ATSDR)
  • Elevated cholesterol (ATSDR)
  • Kidney and testicular cancer (ATSDR)

But That's Not It... Polyester Also Contains Toxic Heavy Metal Residues

Antimony is a toxic heavy metal residue that's permanently fused into polyester fibers.

The EU classifies antimony trioxide as a suspected carcinogen (ECHA). Higher exposures are linked to cardiovascular changes and organ irritation (ATSDR).

Your gym clothes shouldn't come with a chemical exposure warning, but that's exactly what 99% of brands are selling today.

3. Toxic Dyes in Polyester Cause Skin Allergies

Polyester is often colored with disperse dyes (also called azo dyes), and dermatology studies repeatedly flag these synthetic colorants as leading causes of textile-related skin allergies. 

Some disperse dyes are so toxic they're banned by OEKO-TEX® standards for being carcinogenic or allergenic.

Yet brands rarely disclose which specific dyes they use, so you never know which toxic colorants are sitting against your skin during workouts.

4. Your Polyester Clothes Are Poisoning the Planet (And Ending Up in Your Food and Water)

Textile washing is responsible for a shocking 35% of ocean microplastics globally (IUCN, 2017).

Every time you wear, wash, or dry polyester clothing, it dumps plastic straight into the environment.

And these microfibers never just disappear. They flow through treatment plants, rivers, and oceans, where fish and shellfish ingest them.

Multiple studies now document microplastics throughout commercial seafood (PMC, 2022).

On top of that, a 2024 analysis found 110,000–400,000 nanoplastic particles per liter of bottled water (PNAS).

5. Polyester Clothes Host Colonies of Stink-Producing Bacteria

That sharp, unclean smell in your gym clothes that won't come out? It's not just sweat. It's bacterias that live inside polyester fabric.

Scientists found that polyester smelled significantly worse than cotton after having people wear them during exercise (Callewaert et al., 2014).

The reason is simple: polyester attracts Micrococcus bacteria, the exact microbes that create that unmistakable "gym shirt" stench.

Ready to make the switch?

Why thousands are upgrading to natural fabric activewear:

Microplastics-Free

Every part of our clothing is plastic-free, from the label to the stitching.

No Hormone Disrupters

No BPA, no PFAS, no phthalates. No “soft-touch” plastic coatings or chemical finishes.

Skin Friendly Dyes

OEKO-TEX® third-party tested: skin-safe dyes and fabric.

100% Organic Cotton

Made from ultra-soft GOTS certified organic cotton. Designed with an athletic fit.

Naturally Odor Resistant

Unlike polyester, natural fibers are naturally antimicrobial and prevent bacteria buildup.

Environmentally Friendly

Organic cotton is grown without synthetic pesticides/fertilizers and is biodegradable.

VELM vs. The Big Brands

It's us VS. the $350 billion activewear industry. We're on a mission to set a new standard: 100% natural fibers, exceptional design and zero compromises on performance.

Us

OTHER BRANDS

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Natural Fibers Only

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Polyester, Nylon, Elastane

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Microplastic Free

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Sheds Plastic Fibers

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GOTS Certified (Organic)

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Synthetic, Not Organic

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Naturally Breathable Fabrics

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Retains Moisture and Bacteria

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No Hormone Disruptors

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Contains Hormone Disruptors

DISCOVER OUR STORY

Sources: Where Our Facts Come From

1) Microplastics in humans (presence & health signals)

  • Microplastics in human blood — Leslie et al., Environment International (2022). ScienceDirect

  • Microplastics in human placenta — Ragusa et al., Environment International (2021). www2.mst.dk

  • Microplastics in human stool — Schwabl et al., Annals of Internal Medicine (2019). PubMed

  • More MPs in feces of IBD patients — Yan et al., Environmental Science & Technology (2022). PubMed

  • Mechanisms: barriers, inflammation, oxidative stress (review) — Feng et al., Heliyon (2023). ScienceDirect

  • Mechanisms: oxidative stress (review) — Kadac-Czapska & Ośko, Antioxidants (2024). PMC

  • Human exposure routes (review) — Nawab et al., Environmental Advances (2024). ScienceDirect

  • Inhaled MPs — toxicology overview — Borgatta et al., International Journal of Molecular Sciences (2024). PMC

2) PFAS on apparel: migration, dermal uptake & health associations

  • Weathering of PFAS-coated textiles → PFAS emissions & PFAA formation — Schellenberger et al., Environmental Science & Technology (2022). ResearchGate

  • PFAS migration from textiles (artificial saliva) — Danish EPA report (2022). PubMed

  • PFAS dermal absorption in 3D human-skin models — Ragnarsdóttir et al., Environment International (2024). PubMed

  • PFAS apparel migration summary (North American CEC) — Commission for Environmental Cooperation (2023). SpringerLink

  • PFAS health associations (immune, cholesterol, cancers, pregnancy) — ATSDR PFAS Tox Profile/FAQ. American Chemical Society Publications

3) Antimony in polyester (exposure & classifications)

  • Antimony release from polyester into artificial sweat — Biver et al., Regulatory Toxicology and Pharmacology (2021). PMC

  • Antimony in PET & migration context — Welle, Food Additives & Contaminants (2011) review. BioMed Central

  • Antimony toxicology (cardio signs, irritation, dose-dependent) — ATSDR Tox Profile (2019/2022). CottonToday

  • Classification: Antimony trioxide (Carc. 2 EU; IARC Group 2A for trivalent Sb) — ECHA dossier; IARC Monographs Vol. 131 (2023). PMC

4) Disperse dyes in synthetics & textile dermatitis

  • Systematic review — disperse dyes as leading textile allergens — Malinauskiene et al., Contact Dermatitis (2013). American Chemical Society Publications

  • Clinical series — Textile Dye Mix positivity (~2–4%), DB106/DO3 frequent — Sood et al., Contact Dermatitis (2023). European Environment Agency

  • Symptoms & patterns in friction/sweat zones — Svedman et al., Current Dermatology Reports (2019). ScienceDirect

  • Dye release into artificial perspiration (review) — Nicolai et al., Environmental Sciences Europe (2021). IUCN Portals

  • OEKO-TEX® lists of allergenic/carcinogenic dyestuffs (RSL/MRSL) — OEKO-TEX® Standard 100 docs. PLOS

5) Environment: shedding → air & water → seafood/bottled water → people

  • Microfiber release per wash (~hundreds of thousands) — Napper & Thompson, Marine Pollution Bulletin (2016). European Chemicals Agency

  • Primary microplastics to oceans (≈35% from textiles) — Boucher & Friot, IUCN report (2017). ATSDR

  • EU briefing (textiles → 13,000 t/yr to waters) — European Environment Agency (2022). PubMed

  • Vented tumble-dryers emit large fiber counts to air — Kapp & Miller, Environmental Pollution (2020). ScienceDirect

  • Indoor airborne microplastics measured with breathing manikin — Vianello et al., Scientific Reports (2019). ResearchGate

  • Nanoplastics in bottled water (~1.1×10⁵–4×10⁵ L⁻¹) — Qian et al., PNAS (2024). PNAS

6) “Permastink”: odor, microbes & laundering

  • Polyester smells worse than cotton after exercise; microbe profiles (Micrococcus) — Callewaert et al., Applied and Environmental Microbiology (2014). ACP Journals

  • Odor persists on polyester after washing — McQueen et al., Textile Research Journal (2014). American Chemical Society Publications

  • Sportswear odor mechanism (review) — Chang et al., iScience (2023). ACP Journals

  • Laundry reshapes clothing microbiomes; biofilm genes ↑ on synthetics — Díez López et al., BMC Biology (2025). PNAS

  • Fiber governs bacterial activity states — Hoyeck et al., Microbiology Spectrum (2021). ResearchGate
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