Sex Hormones and Their Impact on the Respiratory Responses to Exercise and the Environment

This chapter outlines and describes the effect of sex and variations in the levels of sex hormones via the menstrual cycle and/or oral contraceptive use on the respiratory system responses to exercise and the environment. Based upon the available literature, ventilation at rest is either less or not different in women compared to men and does not appear to vary with changes in sex hormones. Ventilation during exercise is much lower in women compared to men. This difference is due to women having smaller lungs and smaller airways, which limits their ability to generate expiratory flow. However, there are no variations in ventilation during exercise with changes in sex hormones most likely because the ventilatory drive is too robust and tightly coupled to metabolic rate such that the levels of hormones are insufficient to uncouple these parameters. However, there is limited data on the effect of sex and even less on the effect of sex hormones on ventilatory patterns, respiratory mechanics, and pulmonary gas exchange, thus future work is needed.