Álvarez Herms, JesúsJulià Sánchez, SoniaGatterer, HannesCorbí, FranciscoViscor, GinesBurtscher, Martin2020-06-192020-06-192020Álvarez-Herms, J., Julià-Sánchez, S., Gatterer, H., Corbí, F., Viscor, G., & Burtscher, M. (2020). Effects of a Single Power Strength Training Session on Heart Rate Variability When Performed at Different Simulated Altitudes. High Altitude Medicine & Biology, 21(3), 292-296. https://doi.org/10.1089/ham.2020.00141527-02971557-8682http://hdl.handle.net/11268/8977Background: This study assessed heart rate variability (HRV) after a single power strength training session performed at different hypoxic levels. Materials and Methods: Eight physically active subjects (31.1 ± 4.3 years; 177.6 ± 3.0 cm; 70.1 ± 5.2 kg) performed 6 bouts of 15-second continuous maximal jump exercises interspersed by 3 minutes of rest at different altitude levels (total volume of each session: 20 minutes). The normoxic hypoxia levels were FiO2 low altitude: 20.9%; moderate altitude: 16.5%; and high altitude: 13.5%. Results: Average power output during the jumps was similar for all conditions (≅3150 W). Twenty-four hours before (PRE) and 24 hours after (POST) each training session, HRV parameters (R-R, square root of the mean of the sum of differences between intervals [RMSSD], pNN50, and very low frequency, low frequency, and high frequency) were determined without resulting in significant statistical differences, neither from PRE to POST nor between conditions (p > 0.05). Conclusions: This study showed a negligible perturbation of HRV parameters 24 hours after a single power strength session up to a hypoxic level equivalent to 4000 m. Further studies are needed to determine the hypoxia-dependent threshold and intensities of training loads affecting HRV.engjournal article10.1089/ham.2020.0014open accessMedicina deportivaDeportistasAnoxemiaMedicina deportivaAtletaOxígeno