Hughson R L, O'Leary D D, Betik A C, Hebestreit H
Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.
J Appl Physiol (1985). 2000 May;88(5):1812-9. doi: 10.1152/jappl.2000.88.5.1812.
We tested the hypothesis that kinetics of O(2) uptake (VO(2)) measured in the transition to exercise near or above peak VO(2) (VO(2 peak)) would be slower than those for subventilatory threshold exercise. Eight healthy young men exercised at approximately 57, approximately 96, and approximately 125% VO(2 peak). Data were fit by a two- or three-component exponential model and with a semilogarithmic transformation that tested the difference between required VO(2) and measured VO(2). With the exponential model, phase 2 kinetics appeared to be faster at 125% VO(2 peak) [time constant (tau(2)) = 16.3 +/- 8.8 (SE) s] than at 57% VO(2 peak) (tau(2) = 29. 4 +/- 4.0 s) but were not different from that at 96% VO(2 peak) exercise (tau(2) = 22.1 +/- 2.1 s). VO(2) at the completion of phase 2 was 77 and 80% VO(2 peak) in tests predicted to require 96 and 125% VO(2 peak). When VO(2) kinetics were calculated with the semilogarithmic model, the estimated tau(2) at 96% VO(2 peak) (49.7 +/- 5.1 s) and 125% VO(2 peak) (40.2 +/- 5.1 s) were slower than with the exponential model. These results are consistent with our hypothesis and with a model in which the cardiovascular system is compromised during very heavy exercise.
在接近或高于峰值摄氧量（VO₂峰值）的运动转换过程中测得的摄氧量（VO₂）动力学，会慢于低于通气阈值运动时的VO₂动力学。八名健康年轻男性分别以约57%、约96%和约125%的VO₂峰值进行运动。数据采用双组分或三组分指数模型拟合，并通过半对数转换来检验所需VO₂与测得VO₂之间的差异。采用指数模型时，在125%VO₂峰值时[时间常数（τ₂）=16.3±8.8（标准误）秒]的第二阶段动力学似乎比在57%VO₂峰值时（τ₂=29.4±4.0秒）更快，但与96%VO₂峰值运动时（τ₂=22.1±2.1秒）并无差异。在预计需要96%和125%VO₂峰值的测试中，第二阶段结束时的VO₂分别为VO₂峰值的77%和80%。当用半对数模型计算VO₂动力学时，96%VO₂峰值时（49.7±5.1秒）和125%VO₂峰值时（40.2±5.1秒）的估计τ₂比指数模型时更慢。这些结果与我们的假设一致，也与这样一个模型相符，即在极重度运动期间心血管系统会受到损害。
