Cotton Isn’t King: the Best Fabrics for Running

I’m a pretty low-tech guy. Let’s just say that you should probably look elsewhere if you need help putting up your page on the World Wide Web. I’m also a creature of habit and convenience. So when I reach into my drawer for something to run in on a moderately warm day, I’m going to pull out a cotton T-shirt from a race. Given that I go to more than 30 races a year, year in and year out, I’m not at risk anytime soon of running out of them. Many races now give out long-sleeve shirts instead of short-sleeve ones, so I’m covered (sorry, another pun) for much more of the year. Some of my running partners can’t believe how much of my running I do in those shirts. They pay for hightech gear instead of running in the shirts they get for free from signing up for races. What can I say? I’m as behind the times in my shirt selections as I am in my computer programming skills.
What do they have against the classic cotton T-shirt? Same thing that I have against running in cotton sweats. Cotton feels great against your skin—when your skin is dry. But work up a sweat, and cotton absorbs all of that moisture, and your shirt clings to you. If it’s cold outside, you start to feel cold. If it’s hot, you get hotter, because your sweat just continues to gather on your shirt rather than evaporating and therefore cooling you like it’s supposed to.
What’s the alternative? Apparel made from fabrics that provide wicking, or, as the apparel designers like to say, moisture transport. When it’s hot, the apparel moves sweat from your skin to the surface of the garment.
There, it evaporates, so you get cooled. You also feel more comfortable because your running clothes aren’t clinging to you as much. When it’s cold, and you sweat (it does happen), you stay warmer in wicking fabrics because the moisture isn’t held against your skin, so your skin doesn’t start to feel clammy.
Most high-tech warm weather gear is made of CoolMax. Some companies have their own version of a similar fiber, but the principles behind the construction are the same. Shopping for running shorts and singlets is therefore pretty much a no-brainer, given that nearly all of the companies use the same materials. Go with what you like and what fits you best.
Most running shorts these days have a CoolMax liner and some sort of microfiber shell or outer part. At first glance, the shell might look like the 100 percent nylon shorts that were standard for running shorts 20 years ago. But feel them, and you’ll notice how much more comfortable they are. They do a heck of a lot better job with the elements than the old nylons did.
My brother, Charlie, and my co-author, Scott Douglas, swear by CoolMax T-shirts for running in moderate weather. Some companies make long-sleeve versions, and these are great choices when there’s bit of a nip in the air, but it’s not so cold that you need to break out the heavy-duty winter gear. You can find short-sleeve CoolMax shirts for about $20, longsleeve ones for about $5 more.