Assessment of Oxidative Stress Indices and Total Phenolics Concentrations in Obese Adult Women—The Effect of Training with Supplemental Oxygen: A Randomized Controlled Trial

Background: The aim of this study was to determine the effect of using an oxygen-enriched breathing mixture during controlled physical training on blood oxidative stress parameters and total phenolics (TP) concentrations in obese adult women. Methods: A prospective randomized controlled trial study included 60 women aged 19–68 with BMIs greater than 30 kg/m(2). Patients were randomly assigned to the study group (n = 30), which received additional intervention in supplementing the breathing mixture with oxygen at the flow of 6 L/min during training sessions, and the control group (n = 30). At the beginning and at the end of the study, anthropometric assessments (height and weight and BMI) and blood tests (CRP, FRAP, TBARS, TP, BAC, and La) were performed. For each patient, an individual endurance training plan was established on a cycloergometer, including 12 training units, based on a cardiopulmonary exercise test (CPET). Results: A decrease in blood TBARS concentration was observed in each study group. For the control group, the change was more remarkable, and the difference between the groups was significant at (p < 0.05; ES: 0.583). Training with the oxygen breathing mixture increased blood concentrations of TP, while a decrease in TP in blood was observed in the group without oxygen supplementation during physical training. The difference in the responses between the groups was significant at (p < 0.05; ES: 0.657) Conclusions: Increasing the concentration of oxygen in the respiratory mixture under conditions of increased exercise was shown to be safe because it did not exacerbate oxidative stress in the obese group.