Find in Library

Recent technological developments provide easy access to use an artificial oxygen supply (hyperoxia) during exercise training. The aim of this study was to assess the efficacy of a commercially available oxygen compressor inducing low-dose hyperoxia, on limiting factors of endurance performance. Thirteen active men (age 24 &#177; 3 years) performed a high-intensity interval exercise (HIIE) session (5 &#215; 3 min at 80% of W_max, separated by 2 min at 40% W_max) on a cycle ergometer, both in hyperoxia (4 L∙min^&#8722;1, 94% O₂, HYP) or ambient conditions (21% O₂, NORM) in randomized order. The primary outcome was defined as red blood cell deformability (RBC-D), while our secondary interest included changes in muscle oxygenation. RBC-D was expressed by the ratio of shear stress at half-maximal deformation (SS¹/₂) and maximal deformability (EI_max) and muscle oxygenation of the rectus femoris muscle was assessed by near-infrared spectroscopy. No statistically significant changes occurred in SS¹/₂ and EI_max in either condition. The ratio of SS¹/₂ to EI_max statistically decreased in NORM (<i>p</i> &lt; 0.01; &#916;: &#8722;0.10; 95%CI: &#8722;0.22, 0.02) but not HYP (<i>p</i> &gt; 0.05; &#916;: &#8722;0.16; 95%CI: &#8722;0.23, &#8722;0.08). Muscle oxygenation remained unchanged. This study showed that low-dose hyperoxia during HIIE using a commercially available device with a flow rate of only 4 L&#183;min^&#8722;1 may not be sufficient to induce acute ergogenic effects compared to normoxic conditions.