September 01, 2026

What Your Sweat Is Really Absorbing: Why We're Falling Back in Love With Natural Fibres

A love letter to your skin, from dea 🌙

Here's a question we don't ask ourselves nearly enough: when you get hot, what is your workout gear doing to you — and what are you doing to the planet?

We tend to think of clothing as a passive layer. Something we put on and forget about, like wallpaper for your body. But the moment you heat up — mid-flow on the mat, three songs into spin class, easing into a sauna — your skin stops being passive too. Pores open. Blood rushes to the surface. And whatever's sitting against you, natural fibre or plastic-based synthetic, starts moving both ways: into you, and out into the world.

That's the conversation we want to have today. Not from a place of fear — think of it more like finally reading the ingredients label on the thing you've been wearing five days a week. Once you clock the two-way exchange happening between your skin and your clothes, going natural stops feeling like a "wellness trend" and starts feeling like, well... obvious.

Heat: your skin's version of leaving the door unlocked

Your skin is your largest organ, and it is not a wall — it's more like a bouncer who gets a lot more relaxed about who it lets in once you're hot and sweaty. That's exactly why nicotine patches and topical medications are designed to be worn during warmth or activity — heat and blood flow are a fast-pass for absorption.

Great news if what's touching your skin is clean. Less great if it's polyester, nylon, or a chemical wrinkle-resistant finish, all queuing up at the door the moment you break a sweat.

Plot twist: it's not just in your washing machine, it's in you

Most of the microplastics conversation focuses on the ocean — and yes, your washing machine is a real contributor. But here's the part that should really get your attention: microplastics aren't just polluting waterways anymore. They're turning up inside us.

A 2024 study out of the University of New Mexico, published in the journal Toxicological Sciences, tested 62 human placentas...and found microplastics in every single one, with polyethylene (a plastic used in everyday synthetics) the most common culprit.

A separate 2022 study in Environment International found plastic particles in human blood for the first time. Scientists have since found them in lungs, arteries, breastmilk, and even the brain.

Nobody's saying your leggings alone are responsible for that. But every wash, every workout, every hot sweaty gym session where synthetic fibres rub, stretch and shed against your skin is one more small contribution to a body burden scientists are only just starting to measure. As functional medicine physician Dr. Mark Hyman puts it, "polyester and synthetic fibers also are a big issue" — precisely because of what happens every time they're washed and worn.

Natural fibres like organic cotton and merino don't add to that tally. What they shed is cellulose or protein — compostable, not "still here in 200 years and now possibly in your bloodstream."

Sauna time: swap the togs, save your pores

Quick scenario: you finish your workout, then head straight into the sauna in synthetic swimwear or leggings — the hottest, sweatiest test your clothing will ever face.

Neuroscientist Andrew Huberman has said "deliberate heat exposure can be a powerful tool to improve health and longevity" — and he's right, sauna sessions genuinely support cardiovascular health, recovery, and mood. But the benefit is only as clean as what's sitting on your skin while you get it.

Synthetic swimwear is built to survive chlorine and chemical pools, not to sit against wide-open pores for twenty minutes in dry heat. Organic cotton underwear, on the other hand, is breathable, biodegradable, and skips the plastic base and dye-fixatives entirely.

The swap: save the togs for the pool, bring GOTS-certified organic cotton undies for the sauna bench. Your skin (and your lungs) will thank you.

Why natural fibres, in short

They breathe — no chemical coatings required, just cotton doing what cotton does
They don't add to your plastic tally — what sheds is compostable, not forever-plastic
They're gentler on sensitive skin — no resin finishes, no formaldehyde by-products
They return to the earth — instead of sitting in landfill for centuries
They keep the whole chain cleaner — GOTS certification and plant-based dyes mean the people making your clothes stay safer too

This isn't about being precious. It's about making sure the fabric touching your skin at your most open-pored, most alive moments is as clean as everything else you're already mindful of.

Healthy activewear low toxins organic cotton bike shorts

A healthier wardrobe doesn't have to be complicated

At dea, we've never believed that living more consciously means living perfectly.

It's about noticing.

Noticing what we eat.
Noticing what we put on our skin.
Noticing where our clothes come from.
And noticing what touches our bodies for hours every day.

We can't control everything we're exposed to in the modern world.

But we can make little choices.

One natural-fibre garment.

One less plastic layer.

One more organic cotton piece.

One thoughtful purchase instead of three impulsive ones.

Because wellness isn't just what happens in the gym.

It's what happens in the little spaces between everything else.

And sometimes, feeling a little better can begin with something as simple as changing what you're wearing.

Choose natural where you can.
Choose organic where you can.
And above all, choose kindly.

That's the dea way.

One step you can take today 🌿

Don't overhaul the whole wardrobe tonight. Just swap the one piece that touches your skin the most, for the longest, while you're hottest and sweatiest: