#Hypoxia occurs when the oxygen demand of a tissue exceeds its supply. Hence, understanding the body's physiological and coping mechanisms in hypoxic conditions is crucial. NIRS, which measures local tissue oxygenation, has been effectively used in hypoxia and altitude research for many years.
Recent studies increasingly use #NIRS to measure brain and muscle oxygenation simultaneously during hypoxia, particularly during exercise, as hypoxia affects oxygen supply differently across tissues:
🟡 Rupp et al. compared normobaric hypoxia (NH) and hypobaric hypoxia (HH) during aerobic exercise using the OxyMon. They found that HH impaired performance and pacing more than NH due to differences in systemic alterations and cerebral oxygenation, requiring higher adaptive costs to maintain cerebral oxygen delivery.
🔵 Rosales et al. also used the OxyMon to assess acute normobaric and hypobaric hypoxia. They found that muscle oxygenation remained stable, but brain oxygenation decreased at high altitudes, suggesting environmental dependency on cardiac compensation and the need for caution when comparing different hypoxic conditions.
🟡 Baur et al. investigated the effects of load carriage in normoxia and hypoxia on hemodynamics, tissue oxygenation, and metabolism. Using OctaMon and PortaMon, they found that load carriage, especially in hypoxia, reduced cardiorespiratory efficiency and increased strain, potentially raising the risk of altitude sickness.
#fNIRS #altitudesickness #hypoxiccondition #hemodynamics #altitude