Berger Nicolas J A, Campbell Iain T, Wilkerson Daryl P, Jones Andrew M
Department of Exercise and Sports Science, Manchester Metropolitan University, Alsager, UK.
J Appl Physiol (1985). 2006 Sep;101(3):707-14. doi: 10.1152/japplphysiol.00154.2006. Epub 2006 May 11.
The purpose of this study was to examine the influence of acute plasma volume expansion (APVE) on oxygen uptake (V(O2)) kinetics, V(O2peak), and time to exhaustion during severe-intensity exercise. Eight recreationally active men performed "step" cycle ergometer exercise tests at a work rate requiring 70% of the difference between the gas-exchange threshold and V(O2max) on three occasions: twice as a "control" (Con) and once after intravenous infusion of a plasma volume expander (Gelofusine; 7 ml/kg body mass). Pulmonary gas exchange was measured breath by breath. APVE resulted in a significant reduction in hemoglobin concentration (preinfusion: 16.0 +/- 1.0 vs. postinfusion: 14.7 +/- 0.8 g/dl; P < 0.001) and hematocrit (preinfusion: 44 +/- 2 vs. postinfusion: 41 +/- 3%; P < 0.01). Despite this reduction in arterial O(2) content, APVE had no effect on V(O2) kinetics (phase II time constant, Con: 33 +/- 15 vs. APVE: 34 +/- 12 s; P = 0.74), and actually resulted in an increased V(O2peak) (Con: 3.90 +/- 0.56 vs. APVE: 4.12 +/- 0.55 l/min; P = 0.006) and time to exhaustion (Con: 365 +/- 58 vs. APVE: 424 +/- 64 s; P = 0.04). The maximum O(2) pulse was also enhanced by the treatment (Con: 21.3 +/- 3.4 vs. APVE: 22.7 +/- 3.4 ml/beat; P = 0.04). In conclusion, APVE does not alter V(O2) kinetics but enhances V(O2peak) and exercise tolerance during high-intensity cycle exercise in young recreationally active subjects.
本研究旨在探讨急性血浆量扩充（APVE）对高强度运动期间摄氧量（V(O2)）动力学、最大摄氧量（V(O2peak)）以及力竭时间的影响。八名有运动习惯的男性在需要达到气体交换阈值与最大摄氧量差值70%的工作强度下，进行了三次“阶梯式”自行车测力计运动测试：两次作为“对照”（Con），一次在静脉输注血浆容量扩充剂（佳乐施；7毫升/千克体重）后进行。逐次测量肺气体交换情况。APVE导致血红蛋白浓度显著降低（输注前：16.0±1.0 vs.输注后：14.7±0.8克/分升；P<0.001）以及血细胞比容降低（输注前：44±2 vs.输注后：41±3%；P<0.01）。尽管动脉血氧含量有所降低，但APVE对V(O2)动力学没有影响（第二阶段时间常数，Con：33±15 vs. APVE：34±12秒；P = 0.74），实际上还使V(O2peak)增加（Con：3.90±0.56 vs. APVE：4.12±0.55升/分钟；P = 0.006）以及力竭时间延长（Con：365±58 vs. APVE：424±64秒；P = 0.04）。治疗还使最大氧脉搏增强（Con：21.3±3.4 vs. APVE：22.7±3.4毫升/搏；P = 0.04）。总之，在年轻且有运动习惯的受试者进行高强度自行车运动期间，APVE不会改变V(O2)动力学，但会增强V(O2peak)和运动耐力。
