Favier R J, Constable S H, Chen M, Holloszy J O
J Appl Physiol (1985). 1986 Sep;61(3):885-9. doi: 10.1152/jappl.1986.61.3.885.
In situ muscle stimulation in trained and untrained rats was used to reevaluate whether adaptations induced by endurance exercise training result in decreased lactate production by contracting muscles. The gastrocnemius-plantaris-soleus muscle group was stimulated to perform isotonic contractions. After 3 min of stimulation with 100-ms trains at 50 Hz at 60/min, the increases in lactate concentration in the plantaris, soleus, and fast-twitch red muscle (deep portion of lateral head of gastrocnemius) were only approximately 50% as great in trained as in sedentary rats. In the predominantly fast-twitch white superficial portion of the medial head of the gastrocnemius the increase in lactate concentration was 28% less in the trained than in the sedentary group. The decreases in muscle glycogen concentration seen after 3 min of stimulation at 60 trains/min were smaller in the trained than in the untrained group. The reduction in lactate accumulation that occurred in the different muscles in response to training was roughly proportional to the degree of glycogen sparing. These results show that endurance training induces adaptations that result in a slower production of lactate by muscle during contractile activity.
在训练有素和未经训练的大鼠中进行原位肌肉刺激，以重新评估耐力运动训练所诱导的适应性变化是否会导致收缩肌肉的乳酸生成减少。刺激腓肠肌-比目鱼肌-跖肌肌群进行等张收缩。以60次/分钟的频率，用50赫兹、100毫秒的串刺激3分钟后，训练有素的大鼠中，跖肌、比目鱼肌和快肌红肌（腓肠肌外侧头深部）的乳酸浓度增加量仅约为久坐不动大鼠的50%。在腓肠肌内侧头主要为快肌的白色浅部，训练有素的大鼠中乳酸浓度的增加量比久坐不动组少28%。以60次/分钟的频率刺激3分钟后，训练有素的大鼠肌肉糖原浓度的下降幅度小于未训练组。训练后不同肌肉中乳酸积累的减少与糖原节省程度大致成正比。这些结果表明，耐力训练会诱导适应性变化，导致肌肉在收缩活动期间产生乳酸的速度减慢。
