Abstract: A method of determining a ventilatory threshold for a subject engaged in an activity includes sensing heart rate information, breathing rate information, and motion information from the subject via a monitoring device worn by the subject; analyzing the heart rate information to identify one or more points in time where heart rate increased at a steady subject workload; and identifying the ventilatory threshold for the subject as occurring at a point in time where an increase in breathing rate lagged an increase in heart rate. The method also includes modifying when the ventilatory threshold for the subject occurs in time by presenting to the subject musical audio having a tempo correlated to frequency characteristics of a heart rate and/or breathing rate of the subject.

Abstract: A method of controlling a biometric parameter, such as heart rate and/or breathing rate, of a subject engaged in an activity includes sensing the biometric parameter via a monitoring device worn by the subject, determining frequency characteristics of the biometric parameter, and presenting to the subject musical audio having a tempo correlated to the frequency characteristics of the biometric parameter. The tempo of the musical audio presented to the subject may be changed in order to cause a change in the biometric parameter. A method of modulating heart rate of a subject engaged in an activity includes sensing a breathing rate of the subject via a monitoring device worn by the subject, and then presenting to the subject musical audio having a tempo selected to change the breathing rate by an amount sufficient to cause a change in the heart rate.

Abstract: A method of controlling a biometric parameter, such as heart rate and/or breathing rate, of a subject engaged in an activity includes sensing the biometric parameter via a monitoring device worn by the subject, determining frequency characteristics of the biometric parameter, and presenting to the subject musical audio having a tempo correlated to the frequency characteristics of the biometric parameter. The tempo of the musical audio presented to the subject may be changed in order to cause a change in the biometric parameter. A method of modulating heart rate of a subject engaged in an activity includes sensing a breathing rate of the subject via a monitoring device worn by the subject, and then presenting to the subject musical audio having a tempo selected to change the breathing rate by an amount sufficient to cause a change in the heart rate.