Open AccessThe Influence of High-Altitude Acclimatization on Ventilatory and Blood Oxygen Saturation Responses During Normoxic and Hypoxic Testing
Author(s) -
Anton Ušaj,
Stojan Burnik
Publication year - 2016
Publication title -
journal of human kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.735
H-Index - 37
eISSN - 1899-7562
pISSN - 1640-5544
DOI - 10.1515/hukin-2015-0149
Subject(s) - acclimatization , effects of high altitude on humans , zoology , hypoxia (environmental) , pco2 , ventilation (architecture) , medicine , anaerobic exercise , altitude (triangle) , vo2 max , oxygen , oxygen saturation , heart rate , chemistry , physiology , biology , blood pressure , anatomy , mathematics , meteorology , physics , botany , geometry , organic chemistry
We investigated how acclimatization effects achieved during a high-altitude alpinist expedition influence endurance performance, ventilation ([Formula: see text]) and blood oxygen saturation (SaO 2 ) in normoxic (NOR) and hypoxic conditions (HYP). An incremental testing protocol on a cycle ergometer was used to determine the power output corresponding to the Lactate (P LT ) and Ventilatory Threshold (P VT ) in NOR and HYP (FiO 2 =0.13) as indirect characteristics of endurance performance in both conditions. Furthermore, changes in [Formula: see text], SaO 2 , blood pH and P co2 were measured at a similar absolute exercise intensity of 180 W in NOR and HYP conditions. Seven experienced alpinists (mean ± SD: age: 50 ± 6 yrs; body mass: 76 ± 5 kg; body height: 175 ± 8 cm) volunteered to participate in this study after they had reached the summit of Gasherbrum II and Ama Dablam. They had therefore experienced the limitations of their acclimatization. Individual differences of P LT between values reached after and before the expedition (∆P LT ) correlated (r = 0.98, p = 0.01) with differences of SaO 2 (∆SaO 2 ) in HYP, and differences of P VT (∆P VT ) correlated (r = -0.83, p = 0.02) with differences of [Formula: see text] in HYP. The results suggest that the acclimatization may not have an equivocal and simple influence on the performance in hypoxia: enhanced blood oxygen saturation may be accompanied by increased endurance only, when the increase exceeded 2-3%, but enhanced ventilation, when increased more than 10 l/min in HYP, could detrimentally influence endurance.