Long-distance running - online puzzles

Long-distance running, or endurance running, is a form of continuous running over distances of at least eight kilometres (5 miles). Physiologically, it is largely aerobic in nature and requires stamina as well as mental strength.

Among mammals, humans are well adapted for running significant distances, and particularly so among primates. The endurance running hypothesis suggests that running endurance in the genus Homo arose because travelling over large areas improved scavenging opportunities and allowed persistence hunting. The capacity for endurance running is also found in migratory ungulates and a limited number of terrestrial carnivores, such as dogs, wolves and hyenas.

In modern human society, long-distance running has multiple purposes: people may engage in it for physical exercise, for recreation, as a means of travel, for economic reasons, or for cultural reasons. Long distance running can also be used as a means to improve cardiovascular health. Running improves aerobic fitness by increasing the activity of enzymes and hormones that stimulate the muscles and the heart to work more efficiently. Endurance running is often a component of physical military training and has been so historically. Professional running is most commonly found in the field of sports, although in pre-industrial times foot messengers would run to deliver information to distant locations.