10 Fitness Fabrics, Explained

Bamboo pulp yields a natural fabric that’s light, breathable, and moisture-wicking—it also protects your skin from ultraviolet rays. “It feels insanely soft, repels odors, regulates your temperature, and is UPF 50+,” says Tasc Performance designer, Sarah Chase. Tasc Performance and other brands blend chemical-free bamboo with organic cotton, wool, and spandex to make workout clothes like the Nola Crop Hex Print ($58; tascperformance.com) and Cruisin’ 1/4-Zip ($68; tascperformance.com). “Bamboo is the Swiss Army Knife of performance fabrics,” says Tasc. “You could run a marathon, then go to spin class, then run errands, and you’ll stay fresh, dry, and sun-protected.”

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In the battle between cotton and polyester, cotton wins the whiff test. A recent Belgian study found that it gives off less post-workout stench than polyester because synthetic fabrics allow stink-causing bacteria to thrive. But don’t head to spin class in a cotton tee just yet. Cotton absorbs moisture, potentially making you feel like a dishrag during a hard-charging workout. Still, for yoga, weight training, or other low-sweat activities, go with clothes made from cotton blends—like the Anue Dasha Racerback ($48; newbalance.com) in Pima cotton and spandex.

When you’re running, biking, or doing another outdoor activity, you need protection from the elements. No wonder so much outside gear—everything from running shoes such as Brooks Adrenaline ASR 11 GTX ($150; brooksrunning.com) to jackets like the MYTHOS 2.0 GORE-TEX Active Lady Jacket ($260; goreapparel.com)—is made with it. This synthetic membrane coats regular fabrics, making it waterproof and windproof yet allows skin to breathe. “Water from the outside doesn't penetrate, cold wind does not pass through, and perspiration can escape,” says Cindy Otto Woods, North America product champion for Gore Bike Wear and Gore Running Wear.

Famously used to make women’s stockings, the synthetic fabric is soft as silk, mildew resistant, and dries quickly. It’s also breathable and wicks sweat from your skin to the fabric’s surface, where it can evaporate. You’ll find nylon in all kinds of sportswear, like the lucy activewer Sculpting Tank ($65; lucy.com) and Pocket Capri Legging ($79; lucy.com), both made with 87 percent nylon. “It can stand up to even the sweatiest of workouts,” says Isabelle de la Fontaine, lucy product director. “It also has tremendous stretch and recovery, so your pants move with you.”

Polyester is the workhorse of the workout fabrics, the one you see on labels most often. Basically plastic cloth, it’s durable, wrinkle-resistant, lightweight, breathable, and non-absorbent, which means that moisture from your skin evaporates instead of being drawn into the material. Polyester also repels UV rays and insulates you even when it’s wet. That’s why companies like New Balance use polyester in warm-weather wear like the tennis Tournament Dress ($80; newbalance.com) and cold-weather products like the Chameleon Jacket ($150; newbalance.com), which are both 90 percent polyester.

Polyester’s main drawback: the stink factor. Synthetic material can foster bacteria growth, and it also doesn’t dry quite as quickly as polypropylene or nylon.

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Like polyester, polypropylene is made from plastic. But unlike polyester, this synthetic material is totally water-resistant, says Lauren Hallworth, product line manager for Brooks Running apparel. “Even if you’re sweaty after a run and the outside of the shirt is wet, what’s touching you is completely dry,” says Hallworth. “It’s great as a base layer.” Polypropylene forces moisture to pass through its fibers, expelling it to the fabric’s surface where it can evaporate. Brooks Running uses polypropylene to make tops like the Equilibrium Base LS II ($75; brooksrunning.com) and PureProject Seamless Tank II ($55; brooksrunning.com).

Spandex—also known by the brand name Lycra—puts the stretch in workout wear. The synthetic fabric can expand to nearly 600 percent of its size, offers an unrestricted range of motion, and then snaps back in place. Spandex is also breathable, wicks moisture, and dries quickly. Now you know why it’s a staple in form fitting exercise clothes. Some Spandex products, like Oakley’s O-Form fabric, feature something called four-way stretch. Says Stacy Dye, Oakley’s global product director: “The key benefits of O-Form are freedom of movement; less chafing; maximum comfort; and antibacterial and moisture-wicking powers.” You’ll find spandex four-way stretch in bottoms like Oakley’s En Route Round 2 Short ($50; oakley.com) and tops like the Oakley Energy Tank with built-in bra ($65; oakley.com).

Similar to bamboo, TENCEL is made from wood pulp. But TENCEL contains tiny fibrils, or small hairs, that give the fabric sweat-wicking properties and a luxurious texture. “Textiles made from TENCEL are softer than silk and cooler than linen,” says Stacy Dye, Oakley’s global product director. Plus, Tencel is biodegradable, breathable, and resistant to wrinkles. TENCEL is in form-fitting items like the Oakley Stride Tech Tank ($45; oakley.com), which is super strong yet baby-soft.

A staple for hikers, wool is like nature’s performance fabric. The material creates pockets that trap air, so it’s fantastic at regulating heat and keeping your body warm. It’s also breathable and wicks moisture. Bonus: the lightweight fibers don’t retain odors. You’ll find wool in everything from socks and underwear to fashion-forward fitness gear like the Nike Wool and Sheer Women’s Training Top ($95; nike.com) and Nike Dri-FIT Wool Women’s Henley Shirt ($80; nike.com), both 65 percent wool. Nike blends wool with its signature Dri-FIT polyester for excellent insulation and moisture protection.

The secret weapon that keeps X-STATIC, from stinking after a workout: silver. The fabric is woven with this heavy metal, which is an antimicrobial that prevents bacterial and fungal growth. Now, brands like Brooks Running, The North Face, and Lululemon Athletica are using silver in their own products. Says Tara Poseley, chief product officer for lululemon athletica: “It will never wash out or stop working.” Silverescent will keep items like the Run Away Tee ($68; lululemon.com) and Run Swiftly Tech Racerback ($48; lululemon.com) fresh and stench-free forever.