Simpson L Parker, Jones A M, Skiba P F, Vanhatalo A, Wilkerson D
Sport and Health Sciences, University of Exeter, Exeter, United Kingdom.
Int J Sports Med. 2015 Feb;36(2):113-9. doi: 10.1055/s-0034-1389943. Epub 2014 Oct 20.
We investigated the influence of hypoxia on the asymptote (critical power, CP) and the curvature constant (W') of the hyperbolic power-duration relationship, as measured by both conventional and all-out testing procedures. 13 females completed 5 constant-power prediction trials and a 3-min all-out test to estimate CP and W', in both normoxia (N) and moderate hypoxia (H; FiO2=0.13). CP was significantly reduced in hypoxia compared to normoxia when estimated by conventional (H:132±17 vs. N:175±25 W; P<0.001) and all-out methods (H:134±23 vs. N:172±30 W; P<0.01). The W' was not significantly different in hypoxia compared to normoxia when established by conventional (H:12.3±2.7 vs. N:13.2±2.2 kJ) and all-out methods (H:12.0±2.6 vs. N:12.5±1.4 kJ). Estimates of CP and W' obtained with conventional and all-out methods were not significantly different either in normoxia or hypoxia. There was a significant relationship between the % change in CP relative to V̇(O2peak) and the % change in W' in normoxia compared to hypoxia (r=0.83, P<0.001; conventional test). Changes in the W' in hypoxia are related to changes in the CP relative to V̇(O2peak), suggesting that the W' may not be defined simply as an 'anaerobic' energy store.
我们通过传统测试程序和全力测试程序，研究了低氧对双曲线功率-持续时间关系的渐近线（临界功率，CP）和曲率常数（W'）的影响。13名女性在常氧（N）和中度低氧（H；吸入氧分数=0.13）条件下，完成了5次恒定功率预测试验和一次3分钟的全力测试，以估计CP和W'。通过传统方法（H：132±17 vs. N：175±25W；P<0.001）和全力测试方法（H：134±23 vs. N：172±30W；P<0.01）估计时，低氧状态下的CP相较于常氧状态显著降低。通过传统方法（H：12.3±2.7 vs. N：13.2±2.2kJ）和全力测试方法（H：12.0±2.6 vs. N：12.5±1.4kJ）确定时，低氧状态下的W'与常氧状态相比无显著差异。在常氧或低氧状态下，通过传统方法和全力测试方法获得的CP和W'估计值也无显著差异。与低氧相比，常氧状态下CP相对于最大摄氧量（V̇(O2peak)）的百分比变化与W'的百分比变化之间存在显著关系（r=0.83，P<0.001；传统测试）。低氧状态下W'的变化与CP相对于V̇(O2peak)的变化有关，这表明W'可能不能简单地定义为一种“无氧”能量储备。
