A computer linear regression model to determine ventilatory anaerobic threshold

Abstract

Anaerobic threshold is generally determined by simple visual inspection of ventilation or other gas exchange data obtained during incremental exercise. To establish objective criteria for the determination of anaerobic threshold, a computer algorithm was developed that models the ventilatory response to exercise using multisegment linear regression. The best-fit regression model is chosen by minimizing the pooled residual sum of squares. Anaerobic threshold is reported as the 1st break point in that model. The computer-determined anaerobic threshold values for 37 [human] subjects were compared to the subjectively determined values as chosen by 4 independent observers. The observers'' estimates, when pooled to yield a single value for each subject, gave a mean value for the gas-exchange anaerobic threshold of 2.26 .+-. 0.69 l/min. The estimates by the computer method averaged 2.21 .+-. 0.65 l/min. For these 2 methods, r was 0.94.