The Relationship Between Anaerobic Performance Test and Time of Useful Consciousness Determined in Low-Altitude Chamber (25.000 Feet) with Heart Rate Variability

Abstract

Understanding the relationship between anaerobic performance and time of useful consciousness (TUC) is important for individuals engaged in activities at high altitudes such as climbers, pilots, or astronauts. The aim of this research is to investigate the relationship between anaerobic capacity and TUC determined in a low-altitude chamber (LAC), in terms of performance and heart rate variability (HRV), in healthy males. Thirty male participants were included in the study as volunteers (mean age: 23.2±0.8 years; height: 180.6±6.0 cm; weight: 77.0±8.2 kg). In the scope of the research, participants were exposed to oxygen in a LAC at an atmospheric level of 25.000 feet after body measurements were taken on the first day, and TUC was determined. Anaerobic capacities of the participants were determined the following day using the Wingate Anaerobic test (WAnT). HRV was recorded before, during, and after both tests. According to the findings of our research, the parameter changes of Mean-RR, SDNN, and frequency domain parameters HFnu were significant for both WAnT and LAC in terms of TUC in the pre-test, during the test, and post-test periods. RMSSD change was significant for LAC, while LFnu change was significant for WAnT. In intra-group comparisons, there was a significant difference between pre-test and during the test for WAnT, but no significant difference between during the test and post-test. For LAC, there was a significant difference between pre-test and during the test, as well as between during the test and post-test. In terms of the relationship between anaerobic capacity and time to achieve TUC, TUC showed a non-significant negative correlation with relative peak power (r=-0.03; p=0.86), and non-significant positive correlations with total peak power (r=0.19; p=0.31) and total mean power (r=0.23; p=0.23). The most striking result of this research is the lack of significant relationship between TUC duration and anaerobic performance of the participants. Additionally, in terms of TUC, recovery was significant after TUC in LAC, while no recovery was observed after WAnT. According to the results of this research, anaerobic exercises are not a priority in terms of performance and HRV change to increase TUC. Anaerobic performance may not be the primary criterion for personnel selection for high altitude missions.