Gondim Fernando José, Zoppi Cláudio César, Pereira-da-Silva Lúcia, de Macedo Denise Vaz
Laboratório de Imunopatologia Experimental, Universidade Federal de Goiás, Goiânia, Brasil.
Comp Biochem Physiol A Mol Integr Physiol. 2007 Mar;146(3):375-80. doi: 10.1016/j.cbpa.2006.11.002. Epub 2006 Nov 22.
Maximal blood lactate steady state concentration (MLSS) and anaerobic threshold (AT) have been shown to accurately predict long distance events performance and training loads, as well, in human athletes. Horse endurance races can take up to 160 km and, in practice, coaches use the 4 mM blood lactate concentration, a human based fixed concentration to establish AT, to predict training loads to horse athletes, what can lead to misleading training loads. The lactate minimum speed (LMS) protocol that consists in an initial elevation in blood lactate level by a high intensity bout of exercise and then establishes an individual equilibrium between lactate production and catabolism during progressive submaximal efforts, has been proposed as a nonfixed lactate concentration, to measure individual AT and at the same time predicts MLSS for human long distance runners and basketball players as well. The purpose of this study was to determine the reliability of the LMS protocol in endurance horse athletes. Five male horses that were engaged on endurance training, for at least 1 year of regular training and competition, were used in this study. Animals were submitted to a 500 m full gallop to determine each blood lactate time to peak (LP) after these determinations, animals were submitted to a progressive 1000 m exercise, starting at 15 km h(-1) to determine LMS, and after LMS determination animals were also submitted to two 10,000 m running, first at LMS and then 10% above LMS to test MLSS accuracy. Mean LP was 8.2+/-0.7 mM at approximately 5.8+/-6.09 min, mean LMS was 20.75+/-2.06 km h(-1) and mean heart rate at LMS was 124.8+/-4.7 BPM. Blood lactate remained at rest baseline levels during 10,000 m trial at LMS, but reached a six fold significantly raise during 10% above LMS trial after 4000 and 6000 m (p<0.05) and (p<0.01) after 8000 and 10,000 m. In conclusion, our adapted LMS protocol for horse athletes proposed here seems to be a reliable method to state endurance horse athletes LT and MLSS.
最大血乳酸稳态浓度（MLSS）和无氧阈（AT）已被证明能够准确预测人类运动员的长跑项目成绩和训练负荷。耐力赛马比赛赛程可达160公里，而在实际操作中，教练们使用4毫摩尔的血乳酸浓度（这是基于人类的固定浓度）来确定AT，以此预测马匹运动员的训练负荷，这可能会导致误导性的训练负荷。乳酸最低速度（LMS）方案包括通过高强度运动使血乳酸水平先升高，然后在逐渐进行的次最大强度运动过程中建立乳酸生成与分解代谢之间的个体平衡，该方案被提议作为一种非固定乳酸浓度的方法，用于测量个体的AT，同时也能预测人类长跑运动员和篮球运动员的MLSS。本研究的目的是确定LMS方案在耐力赛马运动员中的可靠性。本研究使用了五匹参加耐力训练至少1年且有规律训练和比赛的雄性马匹。让动物进行500米全力疾驰以确定每次血乳酸达到峰值的时间（LP），在这些测定之后，让动物进行从15公里/小时开始的1000米递增运动以确定LMS，在确定LMS之后，还让动物进行两次10000米跑步，第一次以LMS速度，然后以高于LMS速度10%的速度进行，以测试MLSS的准确性。平均LP在约5.8±6.09分钟时为8.2±0.7毫摩尔，平均LMS为20.75±2.06公里/小时，LMS时的平均心率为124.8±4.7次/分钟。在以LMS速度进行10000米试验期间，血乳酸保持在静息基线水平，但在高于LMS速度10%的试验中，在4000米和6000米后血乳酸显著升高至六倍（p<0.05），在8000米和10000米后（p<0.01）。总之，我们在此提出的适用于马匹运动员的LMS方案似乎是确定耐力赛马运动员乳酸阈（LT）和MLSS的可靠方法。
