Researchers at Fu Jen Catholic University in the Taiwan capital Taipei are the first scientists to demonstrate the positive effects of Siberian ginseng, Eleutherococcus senticosus. They tested endurance athletes in a study that holds water and published their results in the Chinese Journal of Physiology.
The first indications of the positive effect of Eleutherococcus senticosus on endurance athletes appeared in older, difficult to access Russian studies. [Altern Med Rev. 2006 Jun; 11(2): 151-5.] In these studies endurance athletes were given several millilitres of a concentrated alcohol solution containing Eleutherococcus senticosus extracts half an hour before being subjected to considerable exertion, after which they exhibited noticeably improved performances.
It's easy to pick holes in the first of these positive studies. More recent studies, which adhere to the rules of scientific research, produced no positive results. They reported for instance that Eleutherococcus senticosus actually increased the effects of stress on immune cells and boosted cortisol levels in athletes. [Life Sci 2001 Dec 14; 70(4): 431-42.]
A review study done in 2005 also suggested that a daily dose of 1000-2000 mg Eleutherococcus senticosus would be of no interest to endurance athletes. [Int J Sport Nutr Exerc Metab. 2005 Feb; 15(1): 75-83.]
The Taiwanese decided to give Eleutherococcus senticosus another chance. They were financed by the Taiwanese ministry of agriculture, not by the supplements industry.
The researchers gave 9 male students, who did 2 hours a day of tennis training, a daily dose of 800 mg Eleutherococcus senticosus for a period of 8 weeks. The extracts were made from the roots and rhizomes of Siberian ginseng, and came from the Chung Mei Pharmaceutical factories. [chungmei.com.tw]
The students were made to cycle twice at 75 percent of their VO2max until they reached exhaustion. On one occasion they had been taking a placebo for two months prior [P]; on the other they had been taking a supplement containing active ingredients [ES].
After taking Eleutherococcus senticosus the students were able to cycle for 23 percent longer during the exertion test than they were after taking the placebo. This was probably because the students burned more fat and less glucose during the first part of the test. The shaded part of the table below shows that their RER was lower after half an hour of cycling.
Supplementation boosted their maximal oxygen uptake by 9 percent. There were no serious side effects, although one student did complain of sleeplessness during the supplementation period.
"Eleutherococcus senticosus supplementation did appear to enhance endurance time during intense submaximal exercises with concomitant increases in free fatty acid availability and utilization in preference over glucose for cellular energy demands", the researchers summarise. "It is concluded that Eleutherococcus senticosus is an effective nutritional ergogenic aids for people who perform endurance exercises, but the exact mechanisms involved need further investigation."
Chin J Physiol. 2010 Apr 30;53(2):105-11.