A method is provided for the automatic control of cycling speed in a human. The method comprises: estimating the subject's actual cycling speed using one or more sensors to thereby obtain a measured speed; determining an error comprising a difference between a desired speed and the measured speed; and outputting, to the subject, a stimulus frequency signal wherein the stimulus frequency signal is based on the error in such a manner that when the subject pedals in a manner that matches a frequency of the stimulus frequency signal, the subject's actual speed controllably tracks the desired speed.