An experiment was performed to demonstrate methods for enabling subjects (Ss) to produce large magnitude heart rate (HR) changes under conditions which include adequate controls for basal HR changes and elicitation of the HR response by breathing changes. The methods used were an attempt to optimize motivational, feedback, and practice variables. Of 9 Ss, 6 displayed mean HR increases ranging from 16.7 bpm to 35.2 bpm. The greatest mean HR decrease for any S was 3.1 bpm. Control procedures indicated that breathing changes accompanying large increases in HR were not sufficient to account for the magnitude of HR change.