Kevin Plank

For years, the knock on sports-apparel maker Under Armour was that it couldn’t get footwear right and couldn’t win over women. It has evolved: Women’s apparel is 29% of UA’s total apparel sales, and its growth has outpaced that of men’s. Shoes make up 14% of UA’s sales, and that business is expanding at a feverish clip. Chalk it all up to Kevin Plank’s relentless drive to take on Nike. (He has reportedly refused numerous offers to sell.) UA’s revenue—$2.3 billion in 2013—grew at a rate nearly three times that of what Nike’s did over the past 12 months. Plank has long talked about his company as if it were a person. Now, at 18, Under Armour is all grown up. —Daniel Roberts