In 1995, Kevin Plank, captain of the Terrapin special teams, formulated the concept of jerseys made of 'micro-fiber'. Georgia tech and Arizona State were the two teams, both from warm states, whom Plank persuaded, to try his new innovation. Plank chose hi-tech fabric which, had qualities that could wick sweat and other moisture to the surface, instead of the fabric absorbing it. Today, Under Armor manufactures a range of sports outfits for men, women and youths. Their collections include inner wear, outer wear, T-shirts, shirts, slides, cleats, terps jersey et al.

Under Armor emphasizes on its range of HeatGear® designed for warm weathers and ColdGear® designed for cold weathers. These outfits work with the body to regulate body temperature, by compressing and doing away with sweat instead of absorbing it. The primary objective of Under Armor garments, is to replace cotton outfits, with micro-fiber material for different weathers. Under Armor also has designed AllSeasonGear, to be worn in climates that fall between hot and cold.

Under Armor garments, are worn by professional football, baseball, and soccer players and also by athletes in collegiate and Olympic Games. Officially, Under Armor is a supplier to the National Hockey League, USA Rugby, the national Lacrosse League, U.S. Ski Team and Major League Lacrosse. Apart from sportsmen, Under Armor is also preferred by soldiers, to be worn beneath their cammos. Under Armor ultimately, aims to provide sportsmen with gears, that would help them remain dry and make them feel lighter in the course of their performance.