Bickham Dale C, Gibbons Carl, Le Rossignol Peter F
School of Health Sciences, Deakin University, Burwood, Australia.
Med Sci Sports Exerc. 2004 Feb;36(2):297-301. doi: 10.1249/01.MSS.0000113667.64064.36.
To determine whether a deviation from linearity occurs in the .VO2-speed relationship, above the lactate threshold (LT) in running; and whether the length of the submaximal exercise bouts alters the magnitude of any deviation.
Ten endurance-trained runners (N = 3 state level, N = 4 club level, and N = 3 recreational) (mean +/- SE; age 24.4 +/- 2.8 yr, mass 76.1 +/- 2.2 kg, .VO2 59.3 +/- 10.6 mL.kg-1.min-1) completed a .VO2, LT test and 10 x 4-min submaximal constant load exercise bouts. Data were evenly spread above and below LT, which was fitted by a dual linear regression model.
There was a significant decrease (51.4%) in slope of the .VO2-speed relationship above LT. The use of 3-min, in comparison with 4-min, submaximal data did not alter the slope of the .VO2-speed regression above LT. There was no significant difference in the .VO2max estimated from the .VO2-speed regression above LT (58.1 +/- 3.3 mL.kg-1.min-1) but a significant difference below LT (63.6 +/- 3.9 mL.kg-1.min-1) to that obtained during the .VO2max test.
Data from the current study suggest that the use of the linear regression of .VO2-speed data below the LT may potentially overestimate the prediction of .VO2 values above LT.
确定跑步时，在乳酸阈（LT）以上，VO₂与速度的关系是否出现线性偏差；以及次最大运动时长是否会改变任何偏差的幅度。
10名耐力训练的跑步者（3名国家级、4名俱乐部级和3名业余级）（平均值±标准误；年龄24.4±2.8岁，体重76.1±2.2 kg，VO₂ 59.3±10.6 mL·kg⁻¹·min⁻¹）完成了VO₂乳酸阈测试和10次4分钟的次最大恒定负荷运动。数据在乳酸阈上下均匀分布，通过双线性回归模型进行拟合。
在乳酸阈以上，VO₂与速度关系的斜率显著下降（51.4%）。与4分钟相比，使用3分钟的次最大数据并未改变乳酸阈以上VO₂与速度回归的斜率。根据乳酸阈以上VO₂与速度回归估计的VO₂max（58.1±3.3 mL·kg⁻¹·min⁻¹）与VO₂max测试期间获得的值无显著差异，但在乳酸阈以下（63.6±3.9 mL·kg⁻¹·min⁻¹）有显著差异。
本研究数据表明，使用乳酸阈以下VO₂与速度数据的线性回归可能会高估乳酸阈以上VO₂值的预测。
