Townsend Nathan E, Nichols David S, Skiba Philip F, Racinais Sebastien, Périard Julien D
Athlete Health and Performance Centre, Aspetar Orthopaedic and Sports Medicine Hospital Doha, Qatar.
Department of Sports Medicine, Advocate Lutheran General Hospital Park Ridge, IL, USA.
Front Physiol. 2017 Mar 23;8:180. doi: 10.3389/fphys.2017.00180. eCollection 2017.
Develop a prediction equation for critical power (CP) and work above CP (W') in hypoxia for use in the work-balance ([Formula: see text]) model. Nine trained male cyclists completed cycling time trials (TT; 12, 7, and 3 min) to determine CP and W' at five altitudes (250, 1,250, 2,250, 3,250, and 4,250 m). Least squares regression was used to predict CP and W' at altitude. A high-intensity intermittent test (HIIT) was performed at 250 and 2,250 m. Actual and predicted CP and W' were used to compute W' during HIIT using differential ([Formula: see text]) and integral ([Formula: see text]) forms of the [Formula: see text] model. CP decreased at altitude ( < 0.001) as described by 3rd order polynomial function ( = 0.99). W' decreased at 4,250 m only ( < 0.001). A double-linear function characterized the effect of altitude on W' ( = 0.99). There was no significant effect of parameter input (actual vs. predicted CP and W') on modelled [Formula: see text] at 2,250 m ( = 0.24). [Formula: see text] returned higher values than [Formula: see text] throughout HIIT ( < 0.001). During HIIT, [Formula: see text] was not different to 0 kJ at completion, at 250 m (0.7 ± 2.0 kJ; = 0.33) and 2,250 m (-1.3 ± 3.5 kJ; = 0.30). However, [Formula: see text] was lower than 0 kJ at 250 m (-0.9 ± 1.3 kJ; = 0.058) and 2,250 m (-2.8 ± 2.8 kJ; = 0.02). The altitude prediction equations for CP and W' developed in this study are suitable for use with the [Formula: see text] model in acute hypoxia. This enables the application of [Formula: see text] modelling to training prescription and competition analysis at altitude.
开发一个用于预测低氧环境下临界功率（CP）和CP以上功率（W'）的方程，以用于功平衡（[公式：见原文]）模型。九名经过训练的男性自行车运动员完成了骑行计时赛（TT；12、7和3分钟），以确定五个海拔高度（250、1250、2250、3250和4250米）下的CP和W'。采用最小二乘法回归来预测海拔高度下的CP和W'。在250米和2250米处进行了高强度间歇测试（HIIT）。使用[公式：见原文]模型的微分（[公式：见原文]）和积分（[公式：见原文]）形式，将实际和预测的CP和W'用于计算HIIT期间的W'。CP在海拔高度下降（<0.001），如三阶多项式函数所描述（=0.99）。W'仅在4250米处下降（<0.001）。双线性函数表征了海拔高度对W'的影响（=0.99）。在2250米处，参数输入（实际与预测的CP和W'）对建模的[公式：见原文]没有显著影响（=0.24）。在整个HIIT过程中，[公式：见原文]返回的值高于[公式：见原文]（<0.001）。在HIIT期间，在250米（0.7±2.0千焦；=0.33）和2250米（-1.3±3.5千焦；=0.30）完成时，[公式：见原文]与0千焦无差异。然而，在250米（-0.9±1.3千焦；=0.058）和2250米（-2.8±2.8千焦；=0.02）时，[公式：见原文]低于0千焦。本研究中开发的CP和W'的海拔预测方程适用于急性低氧环境下的[公式：见原文]模型。这使得[公式：见原文]模型能够应用于海拔高度的训练处方和比赛分析。
