The original sweat suit was a purely functional, two-piece outerwear set designed to protect athletes engaged in sports, such as track and field. Also called tracksuits, many modern versions use technologically advanced textile material. Some are made of thick material while others are thin. Often track pants are made with two-ply construction, or with wicking material designed to keep perspiration away. One type is called tear-away track pants, specially designed for quick removal.
Classic track pants remain popular. Most are made of thick, absorbent cotton fleece, durable on the outside but softly textured on the inside. The waist has either an elastic band or drawstring tie closure; the ankles may or may not have a similar one. Most are loose and baggy, to accommodate additional track apparel worn underneath and to not hinder an athlete’s requirement for physical flexibility. Casual styles, perhaps made of thinner material, might be more form-fitting.
There is a technical reason for the pants’ bagginess — it creates an insulation of air between sweating skin and protective cloth. This effectively keeps a body warm in cold temperatures and relatively cool in warmer temperatures. It also helps prevent the fabric from becoming saturated with sweat. Modern textiles are being used for athletic clothing to address some of these technical issues.
One of the more popular types of track pants features a two-ply construction. The outer shell is usually a polyester synthetic such as nylon with good weatherproof attributes, and the inner lining is a cooling cotton or woven mesh synthetic. Most windbreakers are made this way; it is a good choice for outdoor sports such as cross country running which may disregard inclement weather.
Two technologies in fabrics have significantly changed the traditional track pants. One is called “wicking,” the ability of one side of a specially processed synthetic cloth to attract moisture and force it through to the other side, leaving an active athlete’s skin relatively dry. The other is an elastic fiber commonly called spandex. Its tight, yet comfortable stretch conforms to a body’s every contour. Many professional runners have abandoned track shorts, tank-tops, pants and pullovers for full-body one-piece singlets called speed suits.
One of the functional necessities of track pants is the need, especially for wearing over athletic uniforms, to easily slip into and out of them. This is critically true of some team sports, such as basketball, in which speedily executed rotation of substitution players is an important element of competition. Track pants especially suitable for these players are “tear-away” pants. The front and back halves of the pants are not stitched; they are held together by snap closures. One quick, sharp pull will unsnap the pants into two pieces for instant removal.