RESUMO
BACKGROUND: Physical activity undertaken in the treatment process additionally increases the oxygen demand of the working muscles. It seems interesting to see whether a delivery of an enriched respiratory mixture can have an impact on lower acidification of working muscles and oxygenation of tissues. OBJECTIVES: To assess tissue saturation and the level of acidification at rest and during exercise while breathing atmospheric air or an oxygen-enriched mixture. MATERIAL AND METHODS: Tissue saturation and lactate concentration at rest and during exercise were assessed in 18 females with an average body mass index (BMI) of 42 kg/m2. The study regimen was as follows: day 1 - cardiopulmonary exercise testing (CPET) - determination of the threshold load; day 2 - 20 min of physical effort on a cycloergometer (threshold load, breathing atmospheric air); day 3 - 20 min of physical effort on a cycloergometer (threshold load, breathing mixture enriched with oxygen). Saturation measurements were performed in 3 places on the patient's body by measuring absorbance via near-infrared spectroscopy (NIRS). RESULTS: A significant decrease in heart rate (HR) at rest was found when using the oxygen-enriched air mixture (Z = 2.1339, p = 0.0328 (effect size (ES) = 0.478)). During the exercise, a significant decrease in saturation was shown only for the midpoint of the quadriceps muscles (Z = 2.1572, p = 0.309 (ES = 0.600)). Medium effect sizes were shown by the difference in resting and exercising lactate concentration change between the experimental models studied (Z = 2.5041, p = 0.0122 (ES = 0.707)). In the experimental models studied, different medium effect sizes were demonstrated in the resting and exercising lactate concentration change. CONCLUSIONS: Oxygen-enriched air mixture contributes to reducing hypoxia in working muscles of obese people. Oxygen supplementation can result in higher physical fitness levels. The implementation of oxygen-enriched air mixture is a promising therapeutic strategy for obese patients who exhibit high lactate concentrations after exercise.
