Sex differences in breathing frequency as a marker of the anaerobic threshold

Abstract

The measurement of breathing frequency as an important physiological measure has become of recent interest in the field of exercise physiology. As measurement of the anaerobic threshold often must be completed with equipment which can evaluate gas exchange, it is becoming increasingly important to identify ways in order to easily measure this point during exercise. It is unknown whether breathing frequency can be a reliable marker of anaerobic threshold in both males and females, as existing studies evaluating the agreement between the two thresholds almost exclusively include male subjects. Thresholds such as a breathing frequency threshold may also occur at different time points between males and females, as this has not been explored in previous research so far. The aim of this study was to determine whether a breathing frequency threshold can be used as a reliable marker for the anaerobic threshold, as well as determine any differences in threshold occurrence between males and females. Nine males and 9 females (n=18) were recruited to complete a maximal cardiopulmonary exercise test. Gas exchange, breathing frequency and other cardiopulmonary measurements were obtained to determine the anaerobic threshold, breathing frequency thresholds and ventilatory thresholds. There was close agreement of anaerobic threshold, breathing frequency threshold and ventilatory threshold in females, but not males. There was no significant difference between males and females in occurrence of thresholds when expressed as a percentage of V̇O2peak. It can be concluded that breathing frequency is a reliable marker for anaerobic threshold in females, but not males. This suggests female specific anatomy and physiology may have an impact on breathing patterns during exercise, with a heavier reliance on breathing frequency. This study evaluates differences between male and female agreement of thresholds, which has not been previously investigated.

Date of Award	2021
Original language	English