One of the purposes of Rhythmic Auditory Stimulation (RAS) is to improve the control of dysfunctional movement patterns. This study aimed to extend the line of research by focussing on secondary students with mental retardation and cerebral palsy. According to the study's assumption, cadence can be controlled through a stable and low signal cadence to the benefit of endurance during an aerobic exercise on a stair stepper. Two conditions ("Do your best" and "RAS") were applied in a Latin square design. Results show that in the RAS condition, as compared to the "Do your best" condition, students significantly decreased their cadence, increased their training duration, kept their heart rate between the bounds suggested for aerobic exercise and decreased their intra-individual standard deviations in both cadence and heart rate per minute. The researchers suggest that a variable signal cadence could have an even greater effect on exercise duration. (Contains 4 tables.)