Running's a means for an animal to move on foot. It's defined in sporting terms as a gait in which at some point all feet are off the ground at the same time. This's in contrast to walking, where one foot's always in contact with the ground, the legs are kept mostly straight and the center of gravity rides along fairly smoothly on top of the legs. The term running can refer to any of a variety of speeds ranging from jogging to sprinting. Motion Humans leap from one leg to the other while runn… (More on Running)