Because of the revision of relevant national standards, few products are now directly labeled "polyester" on the label, and most of them have been rewritten as "polyester fiber". Strictly speaking, polyester is just a kind of polyester fiber. For the sake of preciseness, the national standard has already revised polyester fiber into "polyester fiber".
Most of the cotton sweatpants you see are for daily leisure wear or for occasional exercise. Most of them are made of "polyester fiber", which is really used for intense sports. Because the cotton fabric is very hard to dry once sweating, and even clinging to the body is uncomfortable and easy to catch cold. Polyester fabric is one of the fabric components that are more suitable for all kinds of sports in terms of quick drying, lightness, and easy finishing of other special functions.
