Best natural fiber activewear brands
Updated July 19, 2026
The activewear industry is built almost entirely on synthetic fabrics. Polyester, nylon, and spandex dominate because they stretch, dry quickly, and hold their shape through repeated washing. The environmental cost is significant: synthetics shed hundreds of thousands of microplastic fibers per wash cycle, and those particles travel through wastewater treatment systems into rivers and oceans.
Merino wool performs differently from what most people expect of wool. It manages moisture vapor before sweat becomes liquid on skin. It regulates temperature in both directions — cooling during exertion, warming when you stop. And it resists odor more effectively than any synthetic fabric, which means fewer wash cycles and less microplastic shedding over the life of the garment.
The tradeoffs are real. Merino costs more, wears through faster under high abrasion, and is less suitable than synthetics for very high-intensity exercise with significant friction. Organic cotton handles lower-intensity movement well but holds moisture during sustained cardio. The brands below have built activewear lines around these natural materials, each making different choices about where performance and fiber integrity overlap.
Merino wool base layers and cotton outdoor clothing built for hiking, climbing, and running.
Outdoor basics and activewear in merino wool and organic cotton for men and women.
B Corp women's clothing brand using natural and organic fibers, one of the UK's highest B Corp scorers.
Organic cotton clothing for babies and kids, from newborn basics and sleepers to toddler tops and accessories.
100% organic cotton, spandex-free basics and underwear designed for sensitive skin.
Vermont-made merino wool socks for men, women, and kids with a lifetime guarantee.
Swedish outdoor and rain gear brand, fully PFAS-free, for men, women, and kids.
Organic cotton underwear, basics, and lingerie for men and women, made under fair conditions in Europe.
Fair Trade certified basics in organic Peruvian Pima cotton for men and women.
Organic cotton jeans and trousers for men and women, made under GOTS-certified standards by a German family brand.
UK surf and outdoor brand making apparel in organic cotton, hemp, and merino.
Swedish outdoor and casual brand using organic cotton and wool with no PFAS.
US marketplace for independent boutiques carrying many natural fiber brands.
Organic cotton basics and tees for men and women with a carbon offset commitment.
Swedish outdoor brand offering PFAS-free technical apparel with natural fiber options.
New Zealand merino wool outdoor base layers and apparel for men, women, and kids.
Dutch activewear in hemp, organic cotton, and TENCEL for men and women.
Hemp and organic cotton basics and streetwear made with a focus on regenerative agriculture.
Norwegian women's activewear brand making merino wool base layers and technical clothing for outdoor sports.
Organic cotton clothing for babies, kids, and women, certified to the Global Organic Textile Standard.
Merino wool outdoor apparel for men and women with a Himalayan-inspired aesthetic.
American outdoor and casual brand offering cotton and wool clothing free of PFAS.
Organic Fairtrade cotton clothing for babies and children, from everyday basics to outerwear.
Los Angeles brand making organic cotton and TENCEL basics and activewear for women, men, and kids.
100% New Zealand merino wool base layers and travel clothing for men and women.
New Zealand ZQ merino wool ski and outdoor apparel for men and women.
Mongolian cashmere knitwear brand working directly with herder cooperatives.
Danish organic cotton underwear and basics for men and women.
Traceable alpaca clothing and knitwear sourced directly from Peruvian farming communities.
Outdoor brand making apparel in organic cotton, hemp, and merino wool with strong environmental advocacy.
Outdoor and yoga clothing in organic cotton and hemp for men and women.
Affordable luxury basics in cashmere, organic cotton, silk, alpaca, and linen for men and women.
Full-range organic brand offering clothing and underwear in organic cotton, linen, hemp, and merino.
Outdoor apparel in hemp and organic cotton designed for travel and adventure.
Merino wool socks, base layers, and outdoor apparel for men, women, and kids.
German cotton socks, boxer shorts, and everyday basics for men and women made with cotton blends.
Japanese outdoor brand making merino wool and natural material apparel for men and women.
Australian multi-brand natural fiber marketplace carrying hemp, cotton, and linen clothing.
Organic Egyptian cotton baby and toddler clothing, toys, and accessories made with fair trade practices.
German outdoor and casual brand with GOTS-certified products and a PFAS-free commitment.
Organic cotton yoga leggings, sports bras, and tanks made for women, designed for yoga and active movement.
Women's ZQ merino wool dresses engineered to be worn for 100 days without washing.
Merino wool activewear and base layers for men and women at mid-market prices.
Affordable GOTS and Fair Trade organic cotton basics for men and women.
Alabama-made organic cotton socks in a wide range of styles for men and women.
Montana merino wool brand using fiber from the founders' own family ranch, spun and sewn entirely in the USA. Core base layers, mid-layers, and accessories are 100% merino wool.
Is merino wool good for working out?
Yes. Merino wool manages moisture actively — it absorbs sweat vapor before it becomes liquid sweat on the skin, which keeps you drier during moderate-intensity exercise. It regulates temperature in both directions: cooling when you are hot and warming when you cool down. Merino also resists odor significantly better than synthetic fabrics, which means a merino workout shirt can be worn multiple sessions before washing. The tradeoff is durability under high abrasion — merino wears through faster than nylon or polyester.
Can you wear natural fiber activewear for high-intensity exercise?
Natural fiber activewear works well for most exercise types, but there are tradeoffs at high intensity. Merino handles yoga, hiking, running, and gym training well. For very high-intensity exercise with significant skin abrasion (cycling, CrossFit), merino can wear through faster than synthetic alternatives. Organic cotton activewear absorbs sweat well but holds moisture longer than merino or synthetics, which can feel heavy during sustained cardio. A merino-synthetic blend balances performance and durability for demanding use.
Why is synthetic activewear bad for the environment?
Synthetic activewear — polyester, nylon, spandex — sheds microplastic fibers every time it is washed. A single synthetic garment can release hundreds of thousands of microplastic particles per wash cycle. These particles pass through wastewater treatment systems and enter rivers and oceans, where they accumulate in the food chain. Synthetic fabrics are also derived from petroleum and do not biodegrade. Natural fiber activewear sheds natural fibers that break down in the environment without leaving persistent pollutants.
What is the most breathable natural fiber for exercise?
Merino wool is the most versatile natural fiber for exercise. It manages moisture vapor (sweat before it becomes liquid), regulates temperature across a wide range, and wicks moisture away from skin. Linen is also highly breathable and performs well in heat but has limited stretch and feels rough to some. Organic cotton is breathable but holds moisture when saturated with sweat, which can feel heavy. For breathability across temperature ranges and exercise intensities, merino is the strongest choice among natural fibers.
Do natural fiber workout clothes smell less?
Merino wool resists odor significantly better than both cotton and synthetic fabrics. The fiber structure of wool is less hospitable to the bacteria that cause odor, and merino absorbs odor-causing compounds directly into the fiber where they are less volatile. Synthetic fabrics are notorious for retaining odor — polyester in particular develops a persistent smell that intensifies with repeated washing. A merino workout shirt worn and washed regularly will smell less over time than a comparable synthetic garment.