Cotton is comfortable, but when wet from sweat, it gets clammy. Self-wicking polyester is a good fix. But in wind or a temperature drop, it wicks away sweat so quickly, you get uncomfortably cold. Polartec’s engineers have figured out the right balance.
Polartec created its new Delta—a mechanical wicking fabric—to hold sweat close to the skin. It mimics the body’s natural cooling process before sweat evaporates through the fabric and into the air. Its secret: a water-receptive synthetic called Lyocell is knit into fins, similar to those in a car radiator, that absorbs and spreads out perspiration. Polyester between the fins pulls moisture from the fabric and disperses it into the air to limit sogginess. Added odor control and UPF make it ideal for indoor or outdoor training.
This article was originally published in the September/October 2016 issue of Popular Science, under the title “A Shirt For Goldilocks.”