Active wear for runners has come a long way since the days of old cotton sweatpants. Those cotton sweatpants now serve as post-workout lounge wear, while moisture-wicking fabrics take center stage to “take the wet out of sweat.” Nearly all sports apparel manufacturers have some trademark moisture-wicking material: Champion's Double Dry, Nike's Sphere, and Under Armour's ColdGear are a few examples.
But whatever the name, the principle of moisture-wicking fabric remains the same. The fabric moves moisture away from your skin, which keeps your drier and eliminates the cold, clammy feeling of a wet cotton t-shirt. The moisture-wicking properties hold true whether you're wearing a bra or t-shirt on a hot, humid day or layering a moisture-wicking long-sleeved shirt under a vest, another shirt, or jacket for a cold-weather run.