کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2848493 1167425 2006 15 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Influence of hyperoxia on pulmonary O2 uptake kinetics following the onset of exercise in humans
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی فیزیولوژی
پیش نمایش صفحه اول مقاله
Influence of hyperoxia on pulmonary O2 uptake kinetics following the onset of exercise in humans
چکیده انگلیسی

The purpose of this study was to examine the influence of hyperoxic gas (50% O2 in N2) inspiration on pulmonary oxygen uptake (V˙O2) kinetics during step transitions to moderate, severe and supra-maximal intensity cycle exercise. Seven healthy male subjects completed repeat transitions to moderate (90% of the gas exchange threshold, GET), severe (70% of the difference between the GET and V˙O2 peak) and supra-maximal (105% V˙O2 peak) intensity work rates while breathing either normoxic (N) or hyperoxic (H) gas before and during exercise. Hyperoxia had no significant effect on the Phase II V˙O2 time constant during moderate (N: 28 ± 3 s versus H: 31 ± 7 s), severe (N: 32 ± 9 s versus H: 33 ± 6 s) or supra-maximal (N: 37 ± 9 s versus H: 37 ± 9 s) exercise. Hyperoxia resulted in a 45% reduction in the amplitude of the V˙O2 slow component during severe exercise (N: 0.60 ± 0.21 L min−1 versus H: 0.33 ± 0.17 L min−1; P < 0.05) and a 15% extension of time to exhaustion during supra-maximal exercise (N: 173 ± 28 s versus H: 198 ± 41 s; P < 0.05). These results indicate that the Phase II V˙O2 kinetics are not normally constrained by (diffusional) O2 transport limitations during moderate, severe or supra-maximal intensity exercise in young healthy subjects performing upright cycle exercise.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Respiratory Physiology & Neurobiology - Volume 153, Issue 1, August 2006, Pages 92–106
نویسندگان
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