Aportaciones al estudio de la hipoxia normobárica y de la variabilidad y adaptaciones de la frecuencia cardiacaaplicaciones al paracaidismo

Résumé

Objectives To analyze the methods used in hypoxia exposure and to detect its effects in endurance athletes. In addition, to establish the variations that occur in the domains of heart rate variability (HRV) after exposure to normobaric hypoxia (NH). As well as to evaluate the influence of controlled breathing on hypoxia tolerance in skydivers. Finally, to obtain, analyze and compare the heart rates (HR) developed during precision jumps in the two professional teams of the Acrobatic Patrooper Patrol of the Air Force (PAPEA). Methodology The methodology has been divided into four blocks. Each of them responds to a specific objective, in which a different population and a different method have been described. The first block corresponds to a systematic review; the second study involved young volunteers without pathologies; the third was made up of two groups: students and professional parachutists from the Parachute Sapper Squadron and the PAPEA. The fourth study was carried out with the two professional teams of the PAPEA. In the second and fourth blocks, a Polar H10 heart rate monitor was used to record HR and HRV. In the second and third objectives, different HN exposures were performed with the iAltitude® Trainer v2.7 simulator, muscle oxygen saturation (SmO2) was recorded with a Humon Hex® device and arterial oxygen saturation (SatO2) with the device (Nonin model 3018LP). In the fourth study, a stress test with gas analysis was performed on skydivers (Cortex® Analyzer model MetaLyzer 3B). In all the studies, body composition data were obtained (InBody 120® and Omron BF511) and, prior to each study, different tests were performed to rule out contraindications. Results - Short exposures (less than 3 h) to normobaric hypoxia significantly (p<0.05) increased time to exhaustion and long periods (14 h or more) increased (p<0.05) hemoglobin values, while short exposure times were not effective (p>0.05). Altitudes and durations of exposure to hypoxia were very heterogeneous, although 3000 m was the most commonly used. - A 10 min maximum duration exposure at 5050 m does not cause changes (p>0.05) in HRV time and frequency domain, nor (p>0.05) does an exposure at 3200m for 64 min in an interrupted manner (4:4). - Performing controlled diaphragmatic breaths, with high volume and low velocity, increases HN exposure time (p<0.05), SatO2 and SmO2 values (p<0.05). - The first PAPEA team presents lower heart rate values (p<0.05) than the second team. Both teams tend to increase their HR in each jump. Conclusions -Great heterogeneity of times and altitudes to hypoxia is evidenced according to the hematological or sports parameter on which it is intended to act. -Heart rate variability does not show significant changes in the time or frequency domain after exposure to normobaric hypoxia, not being a stressful stimulus. -Diaphragmatic breathing controlled at a high volume and slow rate improves hypoxia tolerance as measured by a normobaric hypoxia tolerance test at 5050 m altitude. -Precision landing jumps cause a high cardiac and metabolic workload that is increased with less experience of the skydiver and in windier environmental conditions