Long-distance running, or endurance running, is a form of continuous running over distances of at least 3 km (1.9 mi). 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 capacity for endurance running is also found in migratory ungulates and a limited number of terrestrial carnivores, such as bears, dogs, wolves and hyenas.