Hypoxia equally reduces the respiratory compensation point and the NIRS-derived [HHb] breakpoint during a ramp-incremental test in young active males.

This study investigated the effect of reduced inspired fraction of O (FiO ) in the correspondence between the respiratory compensation point (RCP) and the breakpoint in the near-infrared spectroscopy-derived deoxygenated hemoglobin signal ([HHb] ) during a ramp-incremental (RI) test to exhaustion. Eleven young males performed, on two separated occasions, a RI test either in normoxia (NORM, FiO  = 20.9%) or hypoxia (HYPO, FiO  = 16%).