A single lap around a typical outdoor track measures 400 metres, or a quarter mile. As a result, 200 metres equals half a lap.
The International Association of Athletics Federations (IAAF), which establishes track size standards for international and elite competitions, established a standard of 400 metres in diameter. Although most tracks do not intend to hold such events and are not required to follow IAAF criteria, most tracks do follow the basic 400-meter configuration. A 200-meter race is a popular track and field event in which competitors must balance endurance and speed while navigating a curve and staggered start.