As long as I’ve been an athlete, I’ve always been a gear head. When other kids were spending money on personal training, camps and acceleration programs, I was busy checking out the latest advances in sporting goods.

In August 2002, before my senior high school football season, I went to a little family owned sports store in Sioux Falls to special order an undershirt made with space-age material proven to wick away sweat better than any product on the market.

As my co-workers can attest from some of our warmer softball games last summer, I sweat — a lot. I felt anything that could help me survive becoming a puddle during two-a-days was worth it, so I paid $30 for a T-shirt and implored the store owner to order more for my teammates.

By mid-season, nearly every player in my 75-man football team owned at least one Under Armour T-shirt. Some owned several. At the time, all the company made was Heat Gear and Cold Gear, available with no sleeves, short sleeves and long sleeves, along with a few sweat bands and skull caps. Now, Under Armour has emerged as a major player in the sporting goods industry, with gear available in sports ranging from hockey and snowboarding to hunting and gold.

For proof of Under Armour’s increasing relevance, look no further than New England Patriots quarterback Tom Brady, a former Nike-endorsed athlete who just signed on with Under Armour.

“Under Armour’s everything I was looking for,” Brady said. “It’s cool. It’s fun. It’s what so many of the kids are wearing, and I like to try to stay cutting-edge. I like the company. I think we’ve got a lot in common. We both want to stay hungry, stay humble.”

Under Armour is still a much smaller company than Nike, the Goliath of the sporting goods industry. But Under Armour is coming on strong and is still on the rise.

How have they done it? Simple. They’ve built their brand around quality and image. Their products are portrayed as roughneck, constructed to survive the wear-and-tear of on-field battle. Their marketing campaigns focus on the blue-collar aspects of sport – training and practice. In fact, it’s rare an Under Armour ad features an athlete on the field of play, but rather the  weight room or practice field. It also helps they’ve focused on endorsing athletes known for near-religious work ethic, including Lindsey Vonn, Ray Lewis, Michael Phelps, Anquan Boldin and Georges St. Pierre.

And now they’ve got Tom Brady, the most mainstream of NFL players. Under Armour may be throwing stones at the Nike empire, but its stones are getting bigger. While Nike has provided its athletes a platform for commentary – as LeBron James’ “Rise” commercial or Tiger Woods’s awkward mea culpa – Under Armour has carefully signed and portrayed athletes who are rarely controversial and inspirational in their work ethic.

Is Under Armour up to the challenge of cutting into Nike’s stronghold? Their slogans say it all:

Nike’s is “Just Do It.”

Under Armour’s is “I Will.”