Résumé
A study was undertaken to evaluate the effect of aerobic training on lactate oxidative capacity during aerobic exercise using [U-<SUP>14</SUP>C] lactate. Male ddY mice were trained by means of treadmill running 5 days a week for 6 weeks. [U-<SUP>14</SUP>C] lactate was injected after the first 5 min of running at a speed of 30m⋅min<SUP>-1</SUP>. The mice then continued to run for another 25 min at the same speed. Expired gas was collected to estimate the amount of <SUP>14</SUP>CO<SUB>2</SUB> expired during the exercise. The amount of [<SUP>14</SUP>C] lactate expired as <SUP>14</SUP>CO<SUB>2</SUB> during the first 10 min after injection of [14C] lactate was significantly higher in the trained group (T) than in the control group (C) . The blood lactate concentration, and muscle lactate concentration in the soleus immediately after exercise were significantly lower in T than in C. The muscle glycogen and blood glucose concentrations were higher in T than in C. It is concluded that aerobic training in mice decreases the blood lactate concentration during exercise, and also enhances oxidative removal of lactate.