Schneider Donald A, Wing Andrew N, Morris Norman R
School of Physiotherapy and Exercise Science, Griffith University, Gold Coast, 9726 Queensland, Australia.
Eur J Appl Physiol. 2002 Nov;88(1-2):100-6. doi: 10.1007/s00421-002-0690-5. Epub 2002 Sep 18.
This study examined the oxygen uptake (VO(2)) and heart rate (HR) kinetics during arm cranking and leg cycling at work rates above the anaerobic threshold (AT). Ten untrained male subjects [21.6 (1.3) years] completed two 7 min 15 s constant-load arm cranking and two leg cycling tests at a power output halfway between the mode-specific AT and peak VO(2). The time constants for phase II VO(2) (tau) and HR (tau) kinetics were determined by fitting a monoexponential curve from the end of phase I until 3 min of exercise. VO(2) tau and HR tau values were significantly (P < 0.001) slower in arm cranking [VO(2) tau = 66.4 (3.0) s; HR tau = 74.7 (4.4) s] than in leg cycling [VO(2) tau = 42.0 (1.9) s; HR tau = 55.6 (3.5) s]. The VO(2) slow component (VO(2SC)) accounted for a significantly (P < 0.001) greater percentage of the total exercise response during arm cranking [23.8 (1.6)%] than during leg cycling [14.2 (1.5)%]. The greater relative VO(2SC) and the slower VO(2) tau with arm exercise are consistent with a greater recruitment of metabolically inefficient type II muscle fibres during arm cranking than during leg cycling.
本研究检测了在高于无氧阈（AT）的工作强度下进行手摇曲柄运动和腿部骑行时的摄氧量（VO₂）和心率（HR）动力学。10名未经训练的男性受试者[21.6（1.3）岁]在特定模式的AT和峰值VO₂之间的功率输出下，完成了两次7分15秒的恒定负荷手摇曲柄运动测试和两次腿部骑行测试。通过拟合从第一阶段结束到运动3分钟的单指数曲线，确定第二阶段VO₂（τ）和HR（τ）动力学的时间常数。手摇曲柄运动时的VO₂τ和HRτ值[VO₂τ = 66.4（3.0）秒；HRτ = 74.7（4.4）秒]显著（P < 0.001）慢于腿部骑行时的[VO₂τ = 42.0（1.9）秒；HRτ = 55.6（3.5）秒]。与腿部骑行[14.2（1.5）%]相比，手摇曲柄运动期间VO₂慢成分（VO₂SC）在总运动反应中所占百分比显著（P < 0.001）更高[23.8（1.6）%]。与腿部骑行相比，手摇曲柄运动时相对更大的VO₂SC和更慢的VO₂τ与代谢效率较低的II型肌纤维募集更多一致。
