Are you a runner? A soccer player? Have you ever competed in a sport, felt the thrill of the game, or raced for the win? Why is it that our best performances are often those played against our toughest competitors? Ask Liliya Sh0bukhova (top right) of Russia when she attained her best marathon time. She won't tell you she did it while training alone. She did it while running—and winning—the 2011 Chicago Marathon, her third consecutive win. It's not just physical competition that inspires us. As many of us can testify, competition affects every aspect of life. The following timeline demonstrates that the competitive instinct has been around for a long time and has produced some staggering results.