Under Armour’s first product was a shirt designed for football.
Kevin Plank created the original shirt after experiencing the problem firsthand as a University of Maryland football player. Traditional cotton undershirts absorbed sweat and became heavy beneath a jersey, while compression shorts made from synthetic material stayed drier. He wanted an undershirt that would move moisture away from the body and help athletes remain lighter and more comfortable.
The first prototype was called Prototype #0037, also known as “The Shorty.” It was a close-fitting performance T-shirt made with microfiber fabric. Plank gave early versions to former Maryland teammates and other football players, including athletes who had reached the NFL, to test and improve the design.
Football was the product’s original sporting context, although Under Armour quickly marketed the technology to athletes in other sports. The brand later expanded into basketball, baseball, running, training, footwear, and everyday apparel. The key distinction is that the shirt was not a football jersey; it was a moisture-wicking undershirt worn beneath a football uniform.