May 2026

Bio-Performance: Our Vision for the Future of Sportswear

Natural fiber versus synthetic, compared across every criterion that matters for health and performance.

Where natural wins, where it loses, and why we dedicated our whole brand to it.

99% of activewear is made from petroleum-based synthetic fibers. Polyester, nylon, elastane.

The same polymer as your plastic water bottle, food packaging and trash bags. That's what sits on your skin every time you train.

How Natural Fibers Compare to Synthetics

Natural wins

Synthetic wins

Microplastic Shedding

Natural fibers shed zero microplastics. They biodegrade. Synthetic sheds plastic every wear, wash, and dry cycle into waterways, oceans, your food, your body.

Chemical Load

Certified natural fibers carry no PFAS, no antimony, no polymer softeners. All polyester tested contains heavy metal residues. PFAS coatings, forever chemicals your body can never eliminate, are standard.

Durability

Synthetic can last a lifetime structurally. Natural fibers require more care and pilling is possible over time. It's possible to engineer for longevity with reinforced seams and tested wash cycles, but polyester has an edge here.

Skin Health

Natural fibers are hypoallergenic and microbiome-compatible. Polyester uses azo dyes that dermatologists flag as a leading cause of textile allergies. Some are banned as carcinogenic by OEKO-TEX®.

Weight

Synthetic achieves ultra-light weights while keeping structure. Natural fibers can lose shape if pushed too thin.

Thermoregulation

Merino and TENCEL™ dynamically regulate temperature, buffering heat and cold in response to your body. Synthetic traps heat against skin with no dynamic response.

Odor Control

Merino's lanolin is naturally antimicrobial. TENCEL™'s smooth fiber surface resists bacterial colonization. Polyester attracts Micrococcus, the bacteria responsible for bad odors. They can survive washing and stay inside the fiber permanently.

Moisture Management

Natural fibers absorb moisture into the fiber and gradually dry it out. Synthetic repels moisture to the surface with coatings including PFAS. The drying is faster but at the cost of toxic chemicals on your skin.

Flame Resistance

Merino is flame resistant without any chemical treatment. Synthetics melt onto skin when exposed to high heat, just like plastic.

Sustainability

Natural fibers biodegrade and return to soil. Synthetic never biodegrades. It stays in the environment for centuries, still shedding microplastics as it slowly breaks apart.

7Natural wins

3Synthetic wins

So Why Do Brands Still Use Synthetic?

Natural fibers win on 7 out of 10 criteria. And the 3 where synthetics win come with serious trade-offs in health and environmental impact.

So why isn't everyone doing this?

It comes down to cost. Natural fibers are significantly more expensive to source, develop, and produce.

TENCEL™ Lyocell costs multiples of what polyester costs per meter.

Non-mulesed merino wool is one of the most expensive fibers on the planet.

Organic cotton costs more than conventional cotton, which itself costs more than polyester.

It's not about performance. Synthetics currently dominate the industry because they're cheaper and faster to produce at scale.

It's also inherently harder to make natural fiber performance wear.

It took us over a year of research, testing, and failed samples to develop the products we have in the range today.

That development process is longer, more expensive, and less forgiving than working with proven synthetic fibers.

This is why our products are priced higher than typical activewear.

But compared to big brands where you pay for the logo and the fabric is still 100% synthetic, we're confident the quality of our products speaks for itself.

Will synthetic activewear disappear? Maybe not today. Maybe not tomorrow.

But we're seeing a lot of people shift to a healthier alternative for their bodies. And that's who we're building VELM for.

Discover Natural Fiber Activewear →