Methods of determining ventilatory threshold

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.

That which is claimed is: 
     
         1 . A method of determining a ventilatory threshold for a subject engaged in an activity, the method comprising:
 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.   
     
     
         2 . The method of  claim 1 , wherein sensing the motion information comprises sensing a speed of the subject and/or a cadence of the subject, and wherein the steady subject workload comprises a steady subject speed and/or cadence. 
     
     
         3 . The method of  claim 1 , wherein sensing the motion information comprises sensing a cadence of the subject and/or motion intensity of the subject, and further comprising identifying an inflection in the subject cadence and/or the subject motion intensity, and wherein analyzing the heart rate and breathing rate information to identify one or more points in time where heart rate increased at a steady subject workload only begins after the inflection in subject cadence and/or subject motion intensity is identified. 
     
     
         4 . The method of  claim 1 , further comprising 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 of the subject. 
     
     
         5 . The method of  claim 1 , further comprising 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 breathing rate of the subject. 
     
     
         6 . The method of  claim 1 , further comprising determining if achieving ventilatory threshold is viable at one or more periods of time when the subject is at a steady workload. 
     
     
         7 . The method of  claim 1 , wherein the monitoring device comprises at least one sensor selected from the group consisting of a PPG sensor, an ECG sensor, an auscultatory sensor, a piezoelectric sensor, a ballistogram sensor, a bioimpedance sensor. 
     
     
         8 . The method of  claim 1 , wherein the monitoring device is configured to be positioned at or within an ear of the subject. 
     
     
         9 . The method of  claim 1 , wherein the monitoring device is configured to be secured to an appendage of the subject. 
     
     
         10 . The method of  claim 1 , wherein the monitoring device is configured to be integrated within or otherwise associated with clothing worn by the subject. 
     
     
         11 . A system for determining a ventilatory threshold for a subject engaged in an activity, the system comprising:
 a monitoring device configured to be worn by the subject, the monitoring device comprising at least one physiological sensor configured to sense heart rate information and breathing rate information, and at least one motion sensor configured to sense motion information; and   at least one processor configured to:   analyze the heart rate information to identify one or more points in time where heart rate increased at a steady subject workload; and   identify 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.   
     
     
         12 . The system of  claim 11 , wherein the at least one motion sensor is configured to sense subject cadence and/or subject motion intensity, and wherein the at least one processor is further configured to identify an inflection in the subject cadence and/or the subject motion intensity. 
     
     
         13 . The system of  claim 12 , wherein the at least one processor is further configured to analyze the heart rate and breathing rate information to identify one or more points in time where heart rate increased at a steady subject workload only after the inflection in the subject cadence and/or the subject motion intensity is identified. 
     
     
         14 . The system of  claim 11 , wherein the monitoring device is further configured to present to the subject musical audio having a tempo correlated to frequency characteristics of a heart rate of the subject. 
     
     
         15 . The system of  claim 11 , wherein the monitoring device is further configured to present to the subject musical audio having a tempo correlated to frequency characteristics of a breathing rate of the subject. 
     
     
         16 . The system of  claim 11 , wherein the at least one processor is further configured to determine if the ventilatory threshold is viable at one or more periods of time when the subject is at a steady workload. 
     
     
         17 . The system of  claim 11 , wherein the at least one physiological sensor is selected from the group consisting of a PPG sensor, an ECG sensor, an auscultatory sensor, a piezoelectric sensor, a ballistogram sensor, a bioimpedance sensor. 
     
     
         18 . The system of  claim 11 , wherein the at least one motion sensor is configured to sense a speed of the subject and/or a cadence of the subject. 
     
     
         19 . The system of  claim 18 , wherein the at least one processor is configured to analyze the heart rate and breathing rate information to identify one or more points in time where heart rate increased at a steady subject speed and/or cadence. 
     
     
         20 . The system of  claim 11 , wherein the monitoring device is configured to be positioned at or within an ear of the subject. 
     
     
         21 . The system of  claim 11 , wherein the monitoring device is configured to be secured to an appendage of the subject. 
     
     
         22 . The system of  claim 11 , wherein the monitoring device is configured to be integrated within or otherwise associated with clothing worn by the subject. 
     
     
         23 . A method of modifying when a ventilatory threshold for a subject engaged in an activity occurs in time, comprising:
 sensing heart rate information from the subject via a monitoring device worn by the subject;   processing the heart rate information to identify one or more points in time where heart rate increased at a steady subject workload and to identify the ventilatory threshold for the subject; and   modifying when the ventilatory threshold occurs in time by presenting to the subject musical audio having a tempo correlated to frequency characteristics of a heart rate of the subject.   
     
     
         24 . The method of  claim 23 , wherein the musical audio is presented to the user via the monitoring device. 
     
     
         25 . The method of  claim 23 , wherein the monitoring device is configured to be positioned at or within an ear of the subject. 
     
     
         26 . The method of  claim 23 , wherein the monitoring device is configured to be secured to an appendage of the subject. 
     
     
         27 . The method of  claim 23 , wherein the monitoring device is configured to be integrated within or otherwise associated with clothing worn by the subject. 
     
     
         28 . A method of modifying when a ventilatory threshold for a subject engaged in an activity occurs in time, comprising:
 sensing breathing rate information from the subject via a monitoring device worn by the subject;   processing the breathing rate information to identify one or more points in time where breathing rate increased at a steady subject workload and to identify the ventilatory threshold for the subject; and   modifying when the ventilatory threshold occurs in time by presenting to the subject musical audio having a tempo correlated to frequency characteristics of a breathing rate of the subject.   
     
     
         29 . The method of  claim 28 , wherein the musical audio is presented to the user via the monitoring device. 
     
     
         30 . The method of  claim 28 , wherein the monitoring device is configured to be positioned at or within an ear of the subject. 
     
     
         31 . The method of  claim 28 , wherein the monitoring device is configured to be secured to an appendage of the subject. 
     
     
         32 . The method of  claim 28 , wherein the monitoring device is configured to be integrated within or otherwise associated with clothing worn by the subject.