Or: Why you should never wear cotton when you know you're going to sweat
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It’s a rainy, chilly day in Seattle and I’m headed outside to walk the dog around the block. When I first moved to this damp region, I would throw on a pair of cotton socks and leggings under a waterproof jacket and call it good. But after several long days of damp feet, I realized: Cotton is a no-go for any kind of physical activity, outdoors or at the gym.
In fact, choosing activewear made of the right materials can be a total game changer, whether you’re exercising, gardening outside, running a marathon, or watching your kid play t-ball, hiking, or (yes) walking the dog in bad weather.
We sweat for good reason: It cools us off and helps our bodies regulate temperature. But that moisture, as well as any absorbed from the weather, can become a problem when it stays on your skin for too long, leading to general discomfort, chafing when the soggy fibers rub the skin, hot and cold flashes, and even hypothermia. "Sweat-wicking" and "moisture-wicking" are buzzy terms in workout and outdoor clothes, but they mean something: They describes the ability of the clothing's fibers to suck up sweat or water and hold that moisture away from your skin as well as dispel it throughout the material (e.g., "wick" it), so it can evaporate more quickly. The end result of wearing the right fabrics: Your skin is drier and your body can regulate its temperature more effectively.
Cotton fabric absorbs moisture and takes forever to dry. You may know from experience that a soaked cotton shirt will stay soaked all day long, and this can be tremendously uncomfortable no matter where you are! At the gym or on a run, this can make your clothes a soggy, heavy, chafe-inducing mess. On the trail or during outdoor sports in cool weather, though, a wet cotton garment can be dangerous, as being wet in chilly temps is a recipe for hypothermia.
Synthetic clothing: These materials, usually made with polyester or nylon, are especially quick drying, so they’re popular with people who will get—and stay—wet. That means you think you’ll be sweating a lot, or if you run warm, or if you live in a wet climate, consider grabbing a synthetic shirt, socks, jacket, or pants. Synthetic fibers are hollow, which means moisture leaves them quickly and you’ll find yourself drying out quickly post-activity, too, usually within the hour. Synthetic materials are also cheaper than wool ones but there is one caution: They tend to pick up and hold onto bad smells. This isn’t an issue if you’re headed home after your run or workout, but if you’re planning to spend a few days in the great outdoors, you might want to grab a wool garment instead.
Wool clothing: We think of wool as a purely winter material, but in fact it's an amazing product to consider wearing year-round. That’s because wool, and especially high-quality wool like Merino, has hollow fibers that wick moisture quickly (similar to synthetics), and it's naturally antimicrobial, meaning it won't hold onto skin bacteria that causes odors. Wool is arguably the best material for keeping your body temperature regulated year-round, and you can buy wool products in varying thicknesses based on the season. Merino wool is the highest quality wool you can buy; brands like Smartwool use it in their products. The wool comes from Merino sheep in New Zealand and athletes typically love the material’s cozy-but-not-itchy feel. Lower quality wool products will still probably work fine but they won’t feel as soft. And while wool is good at moisture management, if you live in a very wet climate, you'll likely find synthetics more comfortable thanks to their quicker drying speed, post-activity.
Your choice of materials matters most for the fabric that is up against your skin and collecting the moisture from your sweat.
Workout tops and bottoms: When you're exercising indoors, you want lightweight synthetic fabrics for maximum moisture management. Consider tops and bottoms designed for runners (even if you’re not running). Nike Dri-Fit and Under Armour Heat Gear are good lines to check out.
Base layers for outdoor activities: Choose a close-fitting long- or short-sleeved top and leggings or long johns so the sweat-wicking magic can happen. Patagonia makes great synthetics, or check out Smartwool for its quality Merino wool options.
Socks: Synthetic or merino wool socks—lightweight for summer, heavyweight for winter—are a foot-comfort must-have. Balega makes cushy-yet-thin synthetics that runners swear by. Most higher-end wool brands, such as Smartwool and Darn Tough, offer a lifetime warranty.
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