Method and system to determine anaerobic threshold of a person non-invasively from freely performed exercise and to provide feedback on training intensity

A system for determining anaerobic threshold intensity (AnT) of a user in a freely performed physical exercise, comprising:

• means for continuously measuring a physiological response of a user by heart rate, wherein a plurality of measured heart rate values are recorded with time stamps as heart rate data;
• means for continuously measuring an external workload including at least one of speed and velocity, wherein a plurality of measured workload values are recorded and each measured workload value is associated with one of the plurality of measured heart rate values to form a plurality of data points;
• means for filtering one or more data points based on a predetermined criteria to form a plurality of accepted data points;
• means for classifying accepted data points within a plurality of heart rate segments representing a heart rate within an anaerobic threshold (AnT) of the user, wherein at least one segment is below a probable heart rate value of AnT, and at least one segment is above the probable heart rate value of AnT;
• means for calculating a first probability factor for each of the plurality of accepted data points based on the measured external workload value and a measured heart rate variability of each data point;
• means for comparing the calculated first probability factor with at least one stored probability factor in a respective segment, and if the first probability factor is higher than the at least one stored probability factor, the first probability factor replaces the at least one stored probability factor in the respective segment so that the data point with the highest first probability factor is stored for each segment;
• means for calculating an estimate of the user's AnT as a weighted value of heart rate values recorded for each segment, wherein each recorded heart rate value in each segment is multiplied by the first probability factor stored for that segment when all weighted values are added together;
• and
• means for outputting and displaying the estimate of the user's AnT.

A method for determining anaerobic threshold intensity (AnT) of a user in a freely performed physical exercise, comprising:

• continuously measuring, by a heart rate sensor, a physiological response of a user by heart rate, wherein a plurality of measured heart rate values are recorded with time stamps as heart rate data;
• continuously measuring an external workload including at least one of speed and velocity, wherein a plurality of measured workload values are recorded and each measured workload value is associated with one of the plurality of measured heart rate values to form a plurality of data points;
• filtering, by a processor, one or more data points based on a predetermined criteria to form a plurality of accepted data points;
• classifying, by the processor, accepted data points within a plurality of heart rate segments representing a heart rate within an anaerobic threshold (AnT) of the user, wherein at least one segment is below a probable heart rate value of AnT, and at least one segment is above the probable heart rate value of AnT;
• calculating, by the processor, a first probability factor for each of the plurality of accepted data points based on at least the measured external workload value and a measured heart rate variability of each data point;
• comparing, by the processor, the calculated first probability factor with at least one stored probability factor in a respective segment, and if the first probability factor is higher than the at least one stored probability factor, the first probability factor replaces the at least one stored probability factor in the respective segment so that the data point with the highest first probability factor is stored in a memory for each segment;
• calculating, by the processor, AnT using the stored probabilities in each segment;
• and
• outputting, by the processor to a display, the estimate of the user's AnT.