McMillan K, Helgerud J, Grant S J, Newell J, Wilson J, Macdonald R, Hoff J
Medical Department, Glasgow Celtic FC, Glasgow, UK.
Br J Sports Med. 2005 Jul;39(7):432-6. doi: 10.1136/bjsm.2004.012260.
To examine the changes in aerobic endurance performance of professional youth soccer players throughout the soccer season.
Nine youth soccer players were tested at six different time points throughout the soccer season by sub-maximal blood lactate assessment, using an incremental treadmill protocol. Whole blood lactate concentration and heart frequency (Hf) were determined at each exercise stage. Running velocities at the first lactate inflection point (v-T(lac)) and at a blood lactate concentration of 4 mmol l(-1) (v-4mM) were determined.
Running velocity at the two lactate thresholds increased from the start of pre-season training to the early weeks of the competitive season, from 11.67 (0.29) to 12.96 (0.28) km h(-1) for v-T(lac), and from 13.62 (0.25) to 14.67 (0.24) km h(-1) for v-4mM (p<0.001). However, v-T(lac )and v-4mM when expressed relative to maximum heart frequency (Hf(max)) remained unchanged. The Hf to blood lactate concentration relationship was unchanged after the pre-season training period. The two expressions of lactate threshold did not reveal differences between each other.
Running velocity at v-T(lac )and v-4mM increased significantly over the pre-season period, but v-T(lac )and v-4mM were unchanged when expressed relative to Hf(max). This finding may indicate that increased endurance performance may be mainly attributable to alterations in Vo(2max). Although lactate assessment of soccer players is useful for determining endurance training adaptations in soccer players, additional assessment of the other two determinants of endurance performance (Vo(2max) and running economy) may provide more useful information for determining physiological adaptations resulting from soccer training and training interventions.
研究职业青年足球运动员在整个足球赛季中无氧耐力表现的变化。
在整个足球赛季的六个不同时间点，对九名青年足球运动员进行次最大血乳酸评估测试，采用递增式跑步机方案。在每个运动阶段测定全血乳酸浓度和心率（Hf）。确定第一个乳酸拐点（v-T(lac)）和血乳酸浓度为4 mmol l(-1)时的跑步速度（v-4mM）。
从季前训练开始到赛季初期，两个乳酸阈值的跑步速度均有所增加，v-T(lac)从11.67（0.29）km h(-1)增加到12.96（0.28）km h(-1)，v-4mM从13.62（0.25）km h(-1)增加到14.67（0.24）km h(-1)（p<0.001）。然而，相对于最大心率（Hf(max)）而言，v-T(lac)和v-4mM保持不变。季前训练期后，心率与血乳酸浓度的关系未发生变化。两种乳酸阈值的表达方式之间未显示出差异。
在季前训练期间，v-T(lac)和v-4mM的跑步速度显著增加，但相对于Hf(max)而言，v-T(lac)和v-4mM保持不变。这一发现可能表明耐力表现的提高主要归因于最大摄氧量（Vo(2max)）的变化。虽然对足球运动员进行乳酸评估有助于确定足球运动员耐力训练的适应性，但对耐力表现的另外两个决定因素（Vo(2max)和跑步经济性）进行额外评估，可能会为确定足球训练和训练干预所导致的生理适应性提供更有用的信息。
