Differing Levels of Acute Hypoxia Do Not Influence Maximal Anaerobic Power Capacity

ObjectiveThe purpose of this study was to determine the effects of different inspired oxygen fractions (Fio2) on average and peak power capacity during consecutive jumps to assess the effectiveness of a hypoxic explosive-strength program.MethodsEight physically active subjects (aged 33.62 ± 4.07 years; height, 1.77 ± 0.05 m; weight, 74.38 ± 6.86 kg) completed a Bosco jump test, consisting of a series of 15-second “all-out” jumps with 3 minutes of recovery, performed in a normoxia condition (N [Fio2 = 21%]) and in two hypoxic conditions: moderate hypoxia (MH [Fio2 16.5% o2]) and high hypoxia (HH [13.5% o2]). A force platform provided the average and the maximal power output (W) generated during consecutive jumps. Measurements were also taken of lactate, creatine kinase, arterial oxygen saturation, and perceived exertion using the Borg fatigue scale.ResultsThe average power outputs throughout the entire sets were similar between N (3187 ± 46) and MH (3184 ± 15; P > .05), but slightly greater with HH (3285 ± 43) compared with N (P < .05). Values for lactate during N (7.5 ± 3.0), MH (7.7 ± 4.0), and HH (7.9 ± 3.0; P > .05), and for creatine kinase (values before, 69.8 ± 15; and 24 hours after in N [79.4 ± 15.60], MH [85.2 ± 26.7], and HH [84.3 ± 47.2]; P > .05) were similar for all conditions. Only during exercise in hypoxia were moderate and severe hypoxemia induced as the sets increased and Fio2 was lower (P < .05). At the same time, the perceived exertion reported by subjects was substantially higher at HH (8.9 ± 1.1) than at N (7.1 ± 1.9; P < .05).ConclusionsJumping power output was not negatively affected by mild or high hypoxia in comparison with normoxia during an anaerobic workout despite having higher hypoxemia and a greater perception of exertion.