Whipp B J, Ward S A, Lamarra N, Davis J A, Wasserman K
J Appl Physiol Respir Environ Exerc Physiol. 1982 Jun;52(6):1506-13. doi: 10.1152/jappl.1982.52.6.1506.
To determine the precise nonsteady-state characteristics of ventilation (VE), O2 uptake (VO2), and CO2 output (VCO2) during moderate-intensity exercise, six subjects each underwent eight repetitions of 100-W constant-load cycling. The tests were preceded either by rest or unloaded cycling ("0" W). An early component of VE, VO2, and VCO2 responses, which was obscured on any single test by the breath-to-breath fluctuations, became apparent when the several repetitions were averaged. These early responses were abrupt when the work was instituted from rest but were much slower and smaller from the 0-W base line and corresponded to the phase of cardiodynamic gas exchange. Some 20 s after the onset of the work a further monoexponential increase to steady state occurred in all three variables, the time constants of which did not differ between the two types of test. Consequently, the exponential behavior of VE, VO2, and VCO2 in response to moderate exercise is best described by a model that incorporates only the second phase of the response.
为了确定中等强度运动期间通气量（VE）、摄氧量（VO2）和二氧化碳排出量（VCO2）的精确非稳态特征，六名受试者每人进行了八次100瓦恒定负荷骑行。测试前受试者处于休息状态或进行无负荷骑行（“0”瓦）。VE、VO2和VCO2反应的早期成分在任何单次测试中都会被逐次呼吸波动所掩盖，但当多次重复测试的结果进行平均时就会变得明显。当从休息状态开始运动时，这些早期反应很突然，但从0瓦基线开始时则慢得多且幅度小得多，并且与心脏动力学气体交换阶段相对应。运动开始约20秒后，所有三个变量进一步呈单指数增加至稳态，两种测试类型的时间常数没有差异。因此，VE、VO2和VCO2对中等强度运动反应的指数行为最好用一个仅包含反应第二阶段的模型来描述。
