When you think about wool, you probably picture an itchy sweater. In fact, wool comes in many different forms, and at its finest—Merino—it can even rival synthetic microfiber, especially when it comes to managing heat, sweat, and odor. There's a reason so much sportswear is made from the stuff—one company has even put the material's natural advantages into a shoe with the Giesswein Merino runner. Think running in wool shoes would make you hot, sweaty and stinky? Think again.
Technically "wool" can refer to the spun hair of many different animals. That includes anything from sheep and goats to rabbits and alpacas; cashmere, angora, and mohair are all considered wool, even though they don't come from sheep. Merino wool, however, only comes from the Merino sheep, a fuzzy, medium-sized animal that originally hails from Spain.
That sheep produces some very fine hair—average Merino wool fibers are around 23 microns in diameter, but can get down below 15 microns. Compare that to a human hair, which is 40 microns. That's important, because the finer the fibers, the softer and smoother the fabric. Wool may have a reputation for being itchy, but Merino wool is anything but. Of course, wool does have a reputation for being hard to care for, but there are ways around that, too. Giesswein, the only shoe on the market with 100% pure merino wool, puts its Merino wool through a 12-hour washing, compression, and agitation process to make sure the final product is not only soft, but machine-washable.
Workout Gear From Nature
Merino wool has some other advantages, as well, especially over other natural fibers. You've probably heard that cotton breathes, which is true. That doesn't make it the best choice for sweaty occasions, however—go for a hike in the summer, and your cotton T-shirt might turn into a soaking, heavy mess; go for a run in winter and you're liable to chill yourself to the bone. That's because as light and breathable as it is, cotton holds onto moisture. Merino wool has the tricky ability to suck moisture into the core of each fiber, but repel moisture on its surface. That means it can help evaporate sweat from your skin without feeling moist—and cold!—to the touch. It also dries in no time.
But it even has an advantage over synthetic fabrics: it won't stink. The fibers are made of keratin, the same stuff that builds your hair and nails, and keratin actually fights bacteria. That, plus the fact that moisture doesn't hang out on the fibers' surface, means that Merino fabric will stay smelling fresh while synthetic fibers, as Gizmodo puts it, have the tendency to "smell like a men's locker room." For this reason, many companies have been producing Merino wool sports apparel, including base layers, T-shirts, and socks. Which brings us back to those Merino runners—if gym shoes don't need anti-stink fabric, we don't know what does.