This post is part of our Battle of the Brands feature. Let us know which brand you prefer, and check out other Battle of the Brands posts.

The story of Nike Inc. (NYSE: NKE) and Under Armour (NYSE: UA) is just one more David and Goliath scenario. Just like in the biblical story, David's battle (UA) was more one of survival against the odds, while Goliath (NKE) truly did want to vanquish the diminutive challenger. Under Armour is capitalized at $1.28 billion while the long-established and legendary Nike has a capitalization more than 20 times the size at $26.38 billion.

NIKE, the world's #1 shoemaker, does more dominating than assisting, to capture more than 20% of the U.S. athletic shoe market. It designs and sells shoes for a variety of sports, including baseball, cheer-leading, golf, volleyball, hiking, tennis, and football. Under Armour is proving its mettle as an apparel warrior. Since its foray into the sporting goods market, the maker of performance athletic undies and apparel has risen to the top of the industry pack, boasting a big portion of the compression garment market.

In addition to playing a dominant role in the shoe market, Nike has retail and wholesale outlets that sell a broad range of branded sports gear, including clothes, watches, balls, hats, and an expanding array of accessories. Under Armour is expanding as well, trying to get a foot-hold (could not resist) in the shoe market starting with a series of cross-trainers. They hope to capture perhaps 10% of the market as they promote their up-and-coming brand.