Exercise-induced arterial hypoxemia; some answers, more questions.

Exercise-induced arterial hypoxemia (EIAH) is characterized by the decrease in arterial oxygen tension and oxyhemoglobin saturation during dynamic aerobic exercise. Since the time of the initial observations, our knowledge and understanding of EIAH has grown, but many unknowns remain. The purpose of this review is to provide an update on recent findings, highlight areas of disagreement, and identify where information is lacking. Specifically, this review will place emphasis on ( i ) the occurrence of EIAH during submaximal exercise, ( ii ) whether there are sex differences in the development and severity of EIAH, and ( iii ) unresolved questions and future directions.