Running

Running, pastime and popular sport since ancient times. Running can be divided into 3 basic classes: sprinting, middle-distance running, and long-distance running. Sub-classes include relay racing, steeple-chasing, and cross-country running. Sprints, fueled by continuous bursts of speed, generally cover distances of 100, 220, and 440 yds (91, 201, and 402 m). At peak speed a champion sprinter may reach 26 mph (42 kmph). The mile (1.6093 km) is the traditional middle-distance race for British and U.S. runners. In long-distance running, defined as 2 miles (3.2 km) and farther, the emphasis is on endurance and pace. The marathon (26 mi, 385 yd/42.2 km) is a popular long-distance race run annually in many cities worldwide.