Is "Cotton Kills" Outdated Advice for Outdoor Adventure?

In the cotton-averse world of performance apparel, this was like admitting that Satisfy used sandpaper in its production process. However, cotton is renowned for its breathability. It's a natural material and, like wool, it's biodegradable, allowing for a circular production process. Merino wool has long been a preferred performance layer thanks to its ability to act as a natural insulator, its antimicrobial properties, and its ability to remain warm when wet and dry quickly. The knock on cotton is that it absorbs moisture, causing it to become wet and heavy when soaked through.

Yet a comprehensive meta-analysis on thermoregulation, comfort, and performance during sport points out that some studies have shown no benefits from wearing polyester compared to cotton. Other studies, they wrote, “have reported significant reductions in core temperature, skin temperature, sweat loss, and heart rate when wearing cotton clothing during exercise compared to synthetic fabrics.” The researchers also highlighted the significant improvement in “thermal sensation” of cotton in hot and dry conditions.

Photo by Graham Hiemstra

In other words, cotton feels good. Perhaps this is what the mountain biking performance apparel manufacturer Curious Creatures recognized when it decided to make an MTB layer out of plain old cotton. The description for the Cottonwood Long Sleeve Tee—which I can attest is both soft and groovy—reads, “We believe in the ineffable comfort of natural fabrics…We find ourselves reaching for them again and again and although lab data shows that plastic ‘performs’ better there is something to the soul of naturals against your skin that can’t be described in numbers.” Maybe it's time we trust our own thermal sensation.

Other brands have started expanding their cotton offerings for sustainability reasons, marketing it as the ideal fabric for travel and daily rigors. Organic cotton uses less water, fertilizer, and pesticides, and can contribute to better soil health. Roark’s Well Worn line and Stio’s Whitebark collection are both made of organic cotton that is perfectly suited to light trail duty. Topo Designs' Dirt Collection is so named both because with it, the company aims to reduce dirty cotton production by using organic cotton, and because the hint of stretch and durability of the long-weave fibers means these garments are intended to get dirty.

If you're planning a high-exertion outing in an environment with the potential to get cold, don’t go with cotton. But if you are like me, cotton will be plenty capable and comfortable for most of your excursions, with the added benefit of being better for the environment, especially if it's organic. Perhaps it's time to kill that old, well-worn saying—“cotton kills”—and to instead educate others on the performance and provenance of all fabrics. The cotton monster only exists in our heads.