In this study, we demonstrated for the first time in humans (n = 9) that sEPOR is downregulated upon daytime exposure to 4 days of intermittent hypoxia (IH; 6 h·day textminus1 , cycles of 2 min of hypoxia followed by 2 min of reoxygenation; peak end-tidal oxygen tension (P ET,O 2 ) 88 Torr, …