Fitness Level– and Sex-Related Differences in Pulmonary Limitations to Maximal Exercise in Normoxia and Hypoxia

Both maximal-intensity exercise and altitude exposure challenge the pulmonary system that may reach its maximal capacities. Expiratory flow limitation (EFL) and exercise-induced hypoxemia (EIH) are common in endurance-trained athletes. Furthermore, because of their smaller airways and lung size, women, independently of their fitness level, may be more prone to pulmonary limitations during maximal-intensity exercise, particularly when performed in hypoxic conditions. The objective of this study was to investigate the impact of sex and fitness level on pulmonary limitations during maximal exercise in normoxia and their consequences in acute hypoxia.