Effects of a 6-week Hypoxia-hyperoxia Exposure Protocol on Sedentary Older Adults on Heart Rate Variability, Blood Pressure, Respiratory Muscle Strength, Pulmonary Function, Inflammatory Biomarkers and Arterial Oxygen Saturation, a Randomized Double-blind Placebo-controlled Clinical Trial

The supply of oxygen is essential for energy production, recovery from efforts, and human life. Intermittent Hypoxia-Hyperoxia Exposure (IHHE) is a novel technique in which the subject is exposed to a respiratory environment with reduced oxygen fraction, controlled through a specific software, using a facial mask and a hypoxic generation device. The objective of this study is to determine if there is a relationship between intermittent hypoxia-hyperoxia exposure and cardiorespiratory condition, blood pressure, and arterial oxygen saturation. According to our hypothesis, acute IHHE in elderly adults may influence cardiorespiratory condition, inflammatory biomarkers, blood pressure, and arterial oxygen saturation. The study will be conducted as a randomized clinical trial. The subjects will be divided into two groups: the experimental group will undergo an IHHE session, breathing air with an oxygen concentration (FiO2) ranging from 10-14% for 1-5 minutes, with 1-3 minutes of rest in hyperoxia (FiO2 30-40%) for a total of 4-8 cycles, based on their acute response to hypoxia. The sham group will undergo a 5-cycle protocol with an FiO2 of 21%. Both groups will follow a 6-week protocol with three weekly sessions (Monday, Wednesday, and Friday).