Walking. Polar bears walk at about five to six kilometers per hour. Females with small cubs slow their speed to two and a half to four kilometers per hour.
Polar bears are well known for their slow, plodding gait. They are able to gallop as fast as a horse over short distances, but they prefer to amble leisurely.
Norwegian scientist Nils Oritsland showed that polar bears expend more than twice the energy of most other mammals when walking or running—showing higher than average increases in temperature and oxygen consumption. When their locomotion is compared with that of their closest living relative, the brown bear, polar bears exhibit what is called “a functional complex adapted to locomotion in a polar environment.”
Walking bears expend 13 times more energy than resting bears. This partly explains their preference for still-hunting, which usually involves a long, patient wait for a seal to surface at a breathing hole in the sea ice.
Running. Polar bears can run as fast as 40 kilometers per hour—but only for short distances. Younger, leaner bears are the best runners. They can cover two kilometers without stopping. Older, larger bears quickly overheat. Much like the dwarves in the classic novel Lord of the Rings, polar bears are natural sprinters, very dangerous over short distances!