Systems and methods are described for automatically adjusting the speed of a treadmill system. The system periodically receives outputs from the range sensor indicative of the position of a user on the treadmill belt. The system calculates an average location when a defined number of outputs have been received, identifies a “zone” corresponding to the average location, and determines a speed adjustment based on the identified zone. After waiting for a defined delay period after receiving the first output of the range sensor, the speed adjustment command is used to adjust the speed of the treadmill motor. The delay period may be defined by the amount of time necessary to receive the defined number of outputs from the range sensor.