Running is by definition the fastest means for an animal to move on foot. It is defined in sporting terms as a gait in which at some point all feet are off the ground at the same time. It is a form of both anaerobic exercise and aerobic exercise. During running, the speed at which the runner moves can be calculated by multiplying the cadence (steps per second) by the stride length.

Running is a complex, coordinated motion which involves the entire body. Every human being runs somewhat differently, but certain general features of the running motions are common.