Anglia Ruskin University, Life Sciences, Unit for Sport and Exercise Science, Cambridge, United Kingdom.
Int J Sports Med. 2010 May;31(5):298-303. doi: 10.1055/s-0030-1248321. Epub 2010 Feb 23.
The purpose of this study was to determine the effects of a reduced whole body blood volume on the kinetic response of VO(2) during moderate and heavy intensity exercise. Six males and four females (age, 21+/-2 yrs; height, 175.2+/-5.1 cm; weight, 66.4+/-2.8 kg; VO(2)max, 53.0+/-4.1 ml x kg (-1) x min(-1)), completed a square-wave cycling ramp test to determine ventilatory threshold (VT) and VO(2max). Kinetics trials were completed 24 h pre and post donation of 450 cm (3) of blood. The kinetics trials were moderate intensity (80%VT) and heavy intensity (Delta50% VT - VO(2max)). Breath-by-breath gas exchange, heart rate, blood pressure, haemoglobin O(2) saturation, and blood [lactate] were measured throughout the trials. Post-donation haemoglobin, haematocrit and erythrocyte count were all significantly reduced (p<or= 0.05). Blood donation caused a significant increase in resting heart rate (P<or= 0.05). There were non-significant differences in the time constants or amplitude of phase II VO(2) kinetics in either moderate or heavy exercise (p>or= 0.05), or in the amplitude of the slow component. The capacity of the cardiovascular system to meet the metabolic demands of skeletal muscle at the onset of exercise does not limit the oxygen uptake.
本研究旨在确定全身血液量减少对中等和高强度运动中 VO(2)动力学反应的影响。6 名男性和 4 名女性（年龄，21+/-2 岁；身高，175.2+/-5.1cm；体重，66.4+/-2.8kg；VO(2)max，53.0+/-4.1ml x kg(-1) x min(-1)）完成了一个方波踏车递增负荷试验，以确定通气阈（VT）和 VO(2)max。动力学试验在献血前 24 小时和献血后 450cm（3）完成。动力学试验为中等强度（80%VT）和高强度（Delta50%VT-VO(2)max）。试验过程中逐口气道气体交换、心率、血压、血红蛋白 O(2)饱和度和血[乳酸]均被测量。献血后血红蛋白、血细胞比容和红细胞计数均显著降低（p<or=0.05）。献血导致静息心率显著增加（p<or=0.05）。在中等或高强度运动中，第二相 VO(2)动力学的时变常数或振幅（p>or=0.05）或缓慢成分的振幅均无显著差异。心血管系统在运动开始时满足骨骼肌代谢需求的能力并不限制氧摄取。
