For example, the company is getting feedback from the athletes on the products' performance.

Burch said Under Armour has grown its endorsement deals with "deliberate, disciplined investments. ... This is just another building block for them to become the brand they want to become. You will see more high-impact signings."

Last week, the company sparked a flurry of rumors when it posted signs on its Locust Point campus welcoming Texas A&M quarterback Johnny Manziel, the 2012 Heisman Trophy winner. Manziel, known as "Johnny Football," visited but there's no news about an endorsement deal, Mirchin said.

Yet.

To get those high-profile contracts means continuing to go up against such sports brand giants as Nike and Adidas.

"Adidas and Nike and a few others have the majority of the market share with long-tenured contracts," Bell said. Under Armour is "stealing that market share, which is a hard thing to do against the likes of those kinds of brands. But they're not afraid to think out of the box or work one on one and get down in the trenches."

Now a $2 billion company that is aiming to grow to $10 billion in sales, Under Armour built its brand on performance apparel, starting with the moisture-wicking T-shirt that Plank developed as a University of Maryland football player seeking a solution to sweat-soaked uniforms.

"They own that space," even after other companies developed similar workout apparel, Burch said. "They've become the Kleenex of their category. You wear Under Armour, you don't wear performance apparel."

Notre Dame was attracted by the prospect of working with Under Armour to improve the performance of the gear and apparel so its student-athletes will have an edge, said John Heisler, senior associate athletics director for Notre Dame. Heisler said he expects coaches and athletes to be actively involved in product research, development and testing.

"The whole business is a lot more than putting a logo on a jersey," Heisler said. "There's a lot at stake, trying to win national championships and trying to win at the highest level with elite athletes. You're looking for every last thing. You're looking for the best possible way to outfit student athletes to give them the best chance for success."

Kirmani said the company needs to continue courting big and small teams, athletes and schools to grow and gain market share from competitors. The recent signings should make it easier to approach both the high-profile and the less-known.

The deals also should help cement Under Armour's "serious performance" image, she said.

"The message that it's serious apparel is resonating," Kirmani said. "They've been able to do that because of the technology and because of innovation. The danger would be if they lost that focus."

lorraine.mirabella@baltsun.com