The aim of this study was to analyze physical performance and physiological variables during High-Intensity Resistance Circuit Training (HRC) with the addition of two levels (moderate and high) of systemic hypoxia.
Twelve resistance-trained young male subjects participated in the study. After a 6RM testing session, participants performed three randomized trials of HRC: normoxia (NORM: FiO2=0.21; ∼0 m altitude), moderate hypoxia (MH: FiO2=0.16; ∼2.100 m altitude) or high hypoxia (HH: FiO2=0.13; ∼3.800 m altitude), as controlled by a hypoxic generator.
Bench press force, heart rate (HR) and heart rate variability (HRV), rating of perceived exertion (RPE), resting metabolic rate (RMR), energy cost (EC) and countermovement jump (CMJ) were assessed in each session. HRV in HH were significantly lower (SDNN = 111.9 vs. 86.7 ms; SDSD = 19.5 vs. 17.0 ms; p≤0.05) in comparison with NORM. There were significant differences in RPE between NORM and HH (11.6 vs. 13.8 points).
Peak and mean force on the bench press were significantly lower (p≤0.05) in HH when compared to MH (Peak: 725 vs 488 N; Mean: 574 vs 373 N). EC was significantly higher (p≤0.01) in both hypoxic conditions compared to NORM (NORM: 10.4; MH: 11.7 HH: 13.3 KJ/min).
There were no differences between conditions in HR and CMJ variables. These results indicate that hypoxic stimuli during HRC exercise alter physical performance and physiological variables and affect how strenuous the exercise is perceived to be. HRC in hypoxia increases the stress on the performance and physiological responses and these differences must be taken into account in order to avoid an excessive overload.
J Strength Cond Res. 2016 Jul 19. [Epub ahead of print] Acute physiological and performance responses to High-Intensity Resistance Circuit Training in Hypoxic and Normoxic Conditions. Ramos-Campo DJ1, Rubio-Arias JA, Freitas T, Camacho A, Jiménez-Diaz JF, Alcaraz PE. 11Department of Physical Activity and Sport Science. Sport Science Faculty. Catholic University of Murcia. Murcia. Spain 2UCAM Research Center for High Performance. Murcia. Spain. 3Laboratory of Physical Performance and Readaptation Injury´s, University of Castilla-La Mancha; Toledo, Spain.