motion of the shoes stops the springs 26 move the magnet to off position turning off the visible or audible signal if desired one reed switch 12 only may be used and only one spring 26 located to bias the spring toward an off position at the end of capsule 22 remote from the reed switch in the actuator of fig1 and its one spring alternative the spring must be yielding enough to permit magnet travel to the on position during walking fig1 a shows an alternative construction wherein capsule 22 containing a single spring 26 biases the magnet 24 out of proximity with the single reed switch 12 under the inertial forces of walking the magnet 24 may move leftward in tube 22 sufficiently to close the single reed switch 12 actuating a sound or light circuit or both during the interval ending when the spring 26 moves the magnet 24 out of effective proximity with reed switch 12 fig1 shows a capsule 22a with a magnet 24 therein fixed in position at the end of capsule 22a biassed to the central off position by the bias magnets 30 and 32 under the motion of walking or running the inertia of the magnet 24 will cause it to slide toward one end or the other of the capsule against a bias to reach an on position and activate a reed switch 12 to cause the audible or visual signal as in the circuits of fig9 or 10 fig1 a shows.