The effect of acute oral glucose administration on high intensity work in fasted rats

The effect of oral glucose administration prior to high intensity work performance was evaluated in fasted rats. Twenty-two male Wistar rats were assigned to one of four groups receiving either, neither or both of glucose and sprint exercise treatment to exhaustion. The mean running time of the glucose treated animals was greater than the non-treated group although this difference was not statistically significant (p greater than 0.05). The blood glucose decreased to 65 +/- 40 mg % in the untreated exercised animals. The respective values in the glucose treated, exercised group were 109 +/- 13 mg % and 167 +/- 33 mg %. The skeletal muscle and liver glycogen concentration was decreased in all animals and more so in the exercised groups. The same pattern was apparent by PAS staining intensity in all three fiber types of the plantaris and soleus muscle. The percent of the glucose does appearing as lactate was greater in exercised animals, however the percent of the lactate derived from the dose was not significantly different (p less than 0.05) from the non-exercised group. The data suggest that the glucose administration to these animals tends to offset the lowering of blood glucose and directly or indirectly contributes to the substrate pool during interval sprint running.