Ginseng is widely touted as enhancing physical performance and health. Chinese researchers examined the effects of ginseng supplementation on exercise performance and the stress response to exercise. Healthy college men were provided a placebo or ginseng (Panax quinquefolium) at a dose of 1600 mg/day for 4 weeks. Subjects then exercised intensely on a treadmill to exhaustion while have blood drawn to measures markers of stress and muscle damage. There was no difference between groups on performance time. However, ginseng supplementation resulted in a significant decrease in blood creatine kinase, a marker of muscle damage. The lower creatine kinase response to exercise indicates that ginseng in some manner protected the integrity of the muscle from mechanical and chemical stresses imposed by exercise. Ginseng also resulted in a lower lactate response, possibly indicating more efficient energy utilization. Although the results do not support ginseng as a performance enhancer, it may aid in recovery from exercise by reducing the amount of damage to the muscle.

Hsu CC, Ho MC, Lin LC, Su B, Hsu MC. American ginseng supplementation attenuates creatine kinase level induced by submaximal exercise in human beings. World J Gastroenterol. 2005 Sep 14;11(34):5327-31.