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—probably because their bodies are so bulky.
Walking bears expend 13 times more energy than resting bears. This explains their preference for still-hunting. Calories expended on a sprint lasting longer than 12 seconds would exceed those gained by a catch.
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.