Roberts Claire L, Wilkerson Daryl P, Jones Andrew M
Department of Exercise and Sport Science, Manchester Metropolitan University, Hassall Road, Alsager, ST & 2HL, UK.
Respir Physiol Neurobiol. 2005 Apr 15;146(2-3):247-58. doi: 10.1016/j.resp.2004.12.012.
The purpose of this study was to characterise, for the first time, the pulmonary O2 uptake (V(O2)) on-kinetic responses to step transitions to moderate and heavy intensity rowing ergometer exercise, and to compare the responses to those observed during upright cycle ergometer exercise. We hypothesised that the recruitment of a greater muscle mass in rowing ergometer exercise (Row) might limit muscle perfusion and result in slower Phase II V(O2) kinetics compared to cycle exercise (Cyc). Eight healthy males (aged 28+/-5 years) performed a series of step transitions to moderate (90% of the mode-specific gas exchange threshold, GET) and heavy (50% of the difference between the mode-specific GET and V(O2) max) work rates, for both Row and Cyc exercise. Pulmonary V(O2) was measured breath-by-breath and the V(O2) on-kinetics were described using standard non-linear regression techniques. With the exception of delta V(O2)delta WR which was approximately 12% greater for Row, the V(O2) kinetic responses were similar between the exercise modes. There was no significant difference in the time constant describing the Phase II V(O2) kinetics between the exercise modes for either moderate (rowing: 25.9+/-6.8 s versus cycling: 25.7+/-8.6 s) or heavy (rowing: 26.5+/-3.0 s versus cycling: 27.8+/-5.1s) exercise. Furthermore, there was no significant difference in the amplitude of the V(O2) slow component between the exercise modes (rowing: 0.34+/-0.13 L min(-1) versus cycling: 0.35+/-0.12 L min(-1)). These data suggest that muscle V(O2) increases towards the anticipated steady-state requirement at essentially the same rate following a step increase in ATP turnover in the myocytes, irrespective of the mode of exercise, at least in subjects with no particular sport specialism. The recruitment of a greater muscle mass in rowing compared to cycling apparently did not compromise muscle perfusion sufficiently to result either in slower Phase II V(O2) kinetics or a greater V(O2) slow component amplitude during heavy exercise.
本研究的目的是首次描述在向中等强度和高强度划船测力计运动进行阶梯式过渡时肺摄氧量（V̇O₂）的动力学反应，并将这些反应与在直立式自行车测力计运动期间观察到的反应进行比较。我们假设，与自行车运动（Cyc）相比，划船测力计运动（Row）中更多肌肉群的募集可能会限制肌肉灌注，并导致第二阶段V̇O₂动力学变慢。八名健康男性（年龄28±5岁）针对Row和Cyc运动进行了一系列向中等强度（特定模式气体交换阈值的90%，GET）和高强度（特定模式GET与V̇O₂max之间差值的50%）工作率的阶梯式过渡。逐次呼吸测量肺V̇O₂，并使用标准非线性回归技术描述V̇O₂的动力学。除了Row的V̇O₂/功率变化（delta V̇O₂/delta WR）大约高12%外，两种运动模式下的V̇O₂动力学反应相似。在中等强度运动（划船：25.9±6.8秒，自行车运动：25.7±8.6秒）或高强度运动（划船：26.5±3.0秒，自行车运动：27.8±5.1秒）中，描述第二阶段V̇O₂动力学的时间常数在两种运动模式之间均无显著差异。此外，两种运动模式下V̇O₂慢成分的幅度也无显著差异（划船：0.34±0.13 L·min⁻¹，自行车运动：0.35±0.12 L·min⁻¹）。这些数据表明，在心肌细胞中ATP周转率阶梯式增加后，肌肉V̇O₂朝着预期的稳态需求增加的速率基本相同，无论运动模式如何，至少在没有特定运动专长的受试者中是这样。与自行车运动相比，划船运动中更多肌肉群的募集显然并未充分损害肌肉灌注，以至于在高强度运动期间导致第二阶段V̇O₂动力学变慢或V̇O₂慢成分幅度增大。
