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

Figures

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  Figure 1. Identification of the RCP and the [HHb]bp with associated V˙O2 during the RI tests performed in normoxia and hypoxia. NORM, normoxia condition (FiO2 = 20.9%); HYPO, hypoxia condition (FiO2 = 16.0%); [HHb], deoxygenated hemoglobin; V˙O2, oxygen uptake; V̇E, minute ventilation; PetCO2: end‐tidal partial pressure of CO2. Dashed vertical line indicates deoxygenated hemoglobin and respiratory compensation point occurrence among the different variables for the same participant in distinct FiO2 condition

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  Figure 2. Bland–Altman plots comparison between the V˙O2 and the PO associated with the respiratory compensation point (RCP) and the deoxyhemoglobin breakpoint ([HHb]bp) for each FiO2 condition. Black lines indicate mean difference error between the oxygen uptake ( V˙O2) associated with RCP and [HHb]bp; Dashed black lines indicate lower and upper limits of agreement (±2 SD). (a) V˙O2 associated with RCP and [HHb]bp in normoxia condition (FiO2 = 20.9%); (b) Power output associated with RCP and [HHb]bp in normoxia condition; (c) V˙O2 associated with RCP and [HHb]bp in hypoxia condition (FiO2 = 16.0%); (b) PO associated with RCP and [HHb]bp in hypoxia condition

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  Figure 3. Correlation and Bland–Altman plots for the V˙O2 and PO delta difference between hypoxia (HYPO) and normoxia (NORM) conditions for the respiratory compensation point (RCP) and deoxyhemoglobin breakpoint ([HHb]bp). (a) correlation for oxygen uptake ( V˙O2) delta change for associated with the RCP and the [HHb]bp between hypoxia and normoxia; (b) V˙O2 delta change for the RCP and the [HHb]bp between hypoxia and normoxia conditions; (c) correlation for power output (PO) delta change for associated with the RCP and the [HHb]bp between hypoxia and normoxia; (d) PO delta change for the RCP and the [HHb]bp between hypoxia and normoxia conditions. Black lines indicate mean difference error and dashed black lines indicate lower and upper limits of agreement