Effect of ginseng saponins on exercise performance in non-trained rats

Short-term (4 days), but not acute, treatment with ginseng saponin (GS, 10 and 20 mg/kg/day) significantly prolonged the aerobic endurance of non-trained rats exercising at approximately 70% VO2max. Compared to the saline controls, GS treatment significantly increased the plasma free fatty acid (FFA) level and maintained plasma glucose level during exercise. Both the liver and skeletal muscle glycogen levels of the GS-treated rats were slightly higher than those of saline-treated controls after exhaustive exercise. These results indicate that GS enhances exercise endurance by altering fuel homeostasis during prolonged exercise, presumably by increasing FFA utilization in preference over glucose for cellular energy demands. To further search for the active components responsible for the ergogenic effect of GS, it was found that a GS preparation devoid of Rg1 and Rb1 failed, whereas injection of either Rg1 or Rb1 enhanced aerobic exercise performance. These results indicate that both Rg1 and Rb1 are key ingredients in GS-mediated enhancement in aerobic endurance.