The effect of breathing an oxygen-enriched mixture on tissue saturation in obese women

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. Materials 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 fol-lows: 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 mea-surements 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 mix-ture (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 con-centrations after exercise.