The claims most pertinent to activity are that it combats fatigue, builds resistance, and improves performance.
None of the benefits of ginseng has been proven by scientific study. Most of the research has been confined to animal and laboratory studies. Well controlled studies in humans showed no beneficial effects on athletic performance.
The best documented side effects are insomnia and to a lesser degree, diarrhea and skin eruptions. Obtaining authentic ginseng has been a problem due to lack of quality control.