While Under Armour doesn't report financials by product type, its latest annual report cites training and hunting gear as a significant driver of recent expansion. In 2013, the company's net sales rose by nearly 30% to $2.2 billion -- the quickest growth in two years.
At the end of the day, that's a small price to pay for a fan demographic unlike any other. NASCAR's efforts to inject youth into auto racing should appeal to current Under Armour customers, while the sport's existing fans -- especially those who are older -- should snatch up more outdoor apparel: a win-win for the company.