Beaver W L, Wasserman K, Whipp B J
J Appl Physiol (1985). 1985 Dec;59(6):1936-40. doi: 10.1152/jappl.1985.59.6.1936.
The pattern of arterial lactate concentration ([La-]) increase during incremental exercise was studied using a transformation defined by plotting log([La-]) vs. log(VO2), where VO2 is O2 uptake. A plot of this function exhibits a phase of very slow increase followed by a phase of rapid increase, defining a transition in the underlying relationship between [La-] and VO2. These phases were found to be linear on the log-log plot; linear regression analysis may therefore be used to locate the transition between them (lactate threshold). A transition point was found at a lower VO2 on the semilog plot of log([La-]) vs. VO2. Consideration of the data from all studies led to the conclusion that a more accurate result is provided by the log-log transformation. This analysis shows lactate to have a small, but significant, increase before the transition and to increase beyond it with a power law having an exponent of about 2.9. This result shows that, during incrementally increasing work rate tests, arterial lactate exhibits a threshold behavior, i.e., an abrupt transition from a phase of slow increase to a phase of rapidly accelerating increase.
通过绘制对数（动脉血乳酸浓度[La-]）与对数（摄氧量VO2）的关系图来研究递增运动期间动脉血乳酸浓度（[La-]）的增加模式，其中VO2是氧摄取量。该函数的图显示出一个非常缓慢增加的阶段，随后是一个快速增加的阶段，这定义了[La-]与VO2之间潜在关系的转变。这些阶段在对数-对数图上被发现是线性的；因此，可以使用线性回归分析来确定它们之间的转变点（乳酸阈值）。在对数（[La-]）与VO2的半对数图上，在较低的VO2处发现了一个转变点。对所有研究数据的考虑得出结论，对数-对数变换提供了更准确的结果。该分析表明，在转变之前乳酸有一个小但显著的增加，并且在转变之后以指数约为2.9的幂律增加。该结果表明，在递增工作率测试期间，动脉血乳酸表现出阈值行为，即从缓慢增加阶段到快速加速增加阶段的突然转变。
