Exercise-induced arterial hypoxemia in aerobic and anaerobic trained athletes during incremental exercise

Abstract

Purpose: The purpose of this study was to examine and compare the occurrence of exercise-induced arterial hypoxemia (EIAH) in aerobic and anaerobic trained athletes during an incremental treadmill exercise test. Material: International level male junior skiers including ten cross-country skiers and ten alpine skiers took part in the study. All participants performed an incremental treadmill exercise test to determine maximal oxygen uptake (VO2max), and oxyhemoglobin saturation (SaO2) was continuously measured using a pulse oximetry. Maximal minute ventilation (VEmax), maximal heart rate (HRmax), ventilatory equivalent for oxygen (VE/VO2) and carbon dioxide (VE/VCO2) were determined during the last stage of the incremental exercise test. EIAH was assumed to have developed when SaO2 decreased by at least 4% (ΔSaO2 ≤ −4%) from the baseline values. Results: VO2max, VE, maximal running speed and test time were higher in the cross-country skiers than in the alpine skiers (p < 0.01), whereas HRmax, VE/VO2 and VE/VCO2 showed similar values in both group (p > 0.05). All the athletes in both groups exhibited EIAH. SaO2 was significantly decreased from 97.5 ± 0.9% at rest to 89 ± 2% at exhaustion in alpine skiers and from 97.8 ± 0.7% at rest to 88.1 ± 2.4% at exhaustion in cross-country skiers (p < 0.001). There were no differences in resting and lowest %SaO2 values between two groups (p > 0.05). Conclusions: EIAH may occur in endurance athletes as well as anaerobic trained athletes. Well-trained athletes who have different aerobic fitness levels may exhibit similar EIAH during the incremental maximal exercise.