The Base Layer of Jogging Clothing

The layer closest to your skin, the base layer, should wick moisture away from your skin to the next layer. So what you want for this layer is a material that is like CoolMax, but a bit heavier. A well-known example is polypropylene. Most of the apparel companies have special names for their versions of these slightly heavier fabrics, such as Nike Dri-F.I.T., Asics Corium, and Hind DryLete. All of them have the same basic construction. The thin fabric consists of two layers. The one closest to the skin is what the apparel people call hydrophobic, or water-hating. It moves sweat to the top layer of the material, which is what called hydrophilic, or water-loving.
In dry, windless conditions down to the low 40s, many runners feel comfortable with just this base layer on. (It’s got to be pretty cold before you need more than one layer on your legs when you’re running.) So if that temperature sounds like close to the coldest you’ll be running in, you’re pretty much set with a pair of tights and a snug top made from one of these microfibers.