Cordyceps and Endurance Performance

Cordyceps Sinensis CS-4 Background:

Cordyceps Sinensis is an essential medicinal mushroom in Traditional Chinese Medicine (TCM). Cordyceps has long been used to treat lung disease, respiratory illness and fatigue. The Cordyceps mushroom grows primarily as a parasitic fungus on caterpillars on the plateau of China and Tibet above 12,000 feet. Tibetan sherpas make tea from the fungus and claim it allows them to climb Mount Everest without supplemental oxygen. Because the mushroom only grows at high altitudes, researchers theorize Cordyceps Sinensis has unique blood-oxygenating properties.

Cordyceps Sinesis CS-4 is a fermentable strain of the mycelia (Paecilomyces hepiali C.) that’s isolated from the natural Cordyceps Sinensis collected from the QuinHai. CS-4 contains the same pharmacologically active compounds as Cordyceps Sinensis, specifically cordycepic acid. It’s important to note the clinical research on endurance, fatigue and VO2 max has only been performed with the CS-4 strain of Cordyceps.

New World Records:

Nobody really understood the endurance benefits of Cordyceps until the Chinese National Games in Beijing.  During these games three world records in the 3,000, 5,000 and 10,000-meter events were broken by athletes who were taking Cordyceps.  The 1994 winter issue of American Entomologist published an article on the incredible rapid ascendancy of the Chinese women’s track team. Chinese coach Ma Zunren stated that intense, high-altitude training and a stress-relieving tonic (prepared from Cordyceps Sinensis) were the factors responsible for record-breaking performances by the athletes.   

Effects of Cordyceps CS-4 on endurance performance in humans:

A study presented at The ACSM annual meeting (Baltimore, MD, June 2001) on elite athletes looked at the effects of Cordyceps CS-4 on endurance performance parameters. The study (which took place in Encinitas, California) concluded that supplementation with Cordyceps CS-4 extract promotes fat metabolism during prolonged exercise. Cordyceps CS-4 supplementation resulted in improved circulatory and metabolic effects during submaximal exercise in endurance-conditioned athletes.  The abstract of the study which was published in the Medicine & Science in Sports & Exercise Journal, 2001, concluded that CS-4 supports normal fat mobilization and beta-oxidation, thereby preserving glycogen usage during prolonged exercise. (Medicine & Science in Sports & Exercise, 2001)

Effects of Cordyceps CS-4 on VO2 max in humans:

A study presented at The Experimental Biology 2001 (FASEB meeting) in Orlando, FL. (April 1, 2001) examined the effects of Cordyceps CS-4 on aerobic capacity of healthy humans. Christopher B. Cooper M.D. professor of medicine and physiology from the University of California, Los Angeles devised the study. The study was published in The Chinese Journal of Gerontology, 2001 edition. Exercise performance was tested before and after six weeks of a treatment using a symptom-limited, incremental work rate protocol on a cycle ergometer. The study, which took place in Beijing, China, concluded that after taking Cordyceps CS-4 for 6 weeks VO2 max significantly increased while the placebo group remained unchanged. The Cordyceps administered group experienced a 6% increase in maximum oxygen uptake from 1.88 to 2.00 liters per minute. These findings support the belief that Cordyceps Sinensis CS-4 has potential for promoting aerobic capacity and resistance to fatigue. (Medicine & Science in Sports & Exercise, 1999)

Effects of Cordyceps CS-4 on endurance in mice:

A double blind, placebo-controlled Chinese study done on mice was conducted to determine if oral administration of Cordyceps CS-4 resulted in enhanced endurance and resistance to fatigue. After three weeks of administration, the groups given CS-4 were able to swim significantly longer than the control groups. The results of the study were dose dependent with results of one group showing a 30% increase in endurance and the second group showing a 73% increase in endurance. The study concluded that the cardiotonic action, inhibition of tracheal constrictions and relaxation of vascular contractions (which CS-4 evokes) elevates the ability and endurance of exercise. (Akinobu, et al. 1995)

Effects of Cordyceps CS-4 on oxygen consumption during state of hypoxia in mice:

Researchers examined oxygen consumption in mice and their ability to survive in a hypoxic (lack of oxygen) environment following Cordyceps CS-4 administration. Under conditions of stimulation of oxygen consumption, subcutaneous injections of CS-4 extract significantly reduced oxygen consumption by 41% to 49% within 10 minutes and by 30% to 36% in the second 10 minutes. In a low oxygen environment, the mice lived 2 to 3 times longer after the CS-4 treatment. The CS-4 induced reduction of oxygen consumption and the prolonged survival of treated animals in a hypoxic environment. (Lou et al., 1986)


Effects of Cordyceps CS-4 on ATP in mice:

A double blind, placebo controlled study looked at the effects of Cordyceps CS-4 on ATP/Pi ratio. The ATP/Pi ratio represents the high-energy state in mice. The study concluded that the CS-4 extract group showed significant increase in the ATP/Pi ratio at weeks 1-3 following supplementation. These results suggest that the high-energy state of the liver in the CS extract-treated mice is a primary effect of repeated administration of the CS extract. (Noboru, et. al, 1996)

The effects of Cordyceps extracts on the energy state of mice were examined using in vivo NMR spectroscopy. In the seven days that the CS-4 extract was administered, the ratio of Adenosine Triphosphate (ATP) to inorganic phosphate (Pi) in the liver was significantly increased by an average of 45% to 55% as compared to the placebo controlled group. (Manabe, 1996)

Although a number of studies have been conducted on Cordyceps in China, there haven’t been many studies done on endurance athletes in the United States.   It’s also hypothesized that the limited studies done in the U.S may have been too short in duration and/or performed using too small of a dose.  While a number of the studies done in the US showed results that mirrored the results of the studies done in China, there were some that were not 100% conclusive. In order to confirm the benefits of Cordyceps, scientists in the US started studying a more easily identifiable and reproducible strain called Cordyceps Militaris.


Cordyceps Militaris study on trained Cyclists:

Cordyceps Militaris is a mycelial biomass cultured from oats.  This strain is similar to Sinensis yet has larger quantities of the active constituents making it an effective substitute.  

A 2016 study using this new strain showed significant improvements in time to exhaustion, peak power output and ventilatory threshold in cyclists.

Twenty-eight healthy and trained college students underwent this double blind, placebo controlled study at the University of North Carolina using an acute and prolonged supplementation period.   The average age was 22 years old with an average weight of 155lbs.  

Athletes were randomly placed in a placebo group or a supplementation group.  The supplementation group consumed Cordyceps Militaris for three weeks and were measured for VO2, time to exhaustion, ventilatory threshold at baseline at week 1 and week 3.  


Following one-week of supplementation, time-to exhaustion-improved in the supplementation group.  


After three weeks, the supplementation group increased peak power by 17% whereas the placebo group decreased by 11%.  The supplementation group also improved their time-to-exhaustion by seventy (70) seconds compared to a five (5) second reduction in placebo.  


In addition, ventilatory threshold* was further improved in week three. (Katie R. Hirsch, et. al. 2016)

Mechanism of action: Recent clinical research supports the anti-fatigue claims of Cordyceps Sinensis in TCM. Cordyceps CS-4 research shows that it can increase endurance and energy through more efficient enzyme activity of red blood cells while improving lung and kidney function. CS-4 mobilizes free fatty acids and beta-oxidation, thereby preserving glycogen usage during prolonged exercise. (Medicine & Science in Sports & Exercise, 2001) In both animal and human studies, CS-4 has proved to support the enzyme superoxide dismutase (SOD), showing its effectiveness as an antioxidant. (J. Zhu, 1999). In a human study, Cordyceps has proved to improve lactate energy metabolism within the cell. (Burke, Edmund 1998)   It’s also been shown to improve oxygen utilization, blood flow and therefore help clear lactate. (Ko et. al, 2007, Zhu et. al, 1998)  Supplementation has been shown to improve aerobic performance, showing improvements in maximal oxygen consumption and ventilatory threshold. (Chen et al., 2010)    

Toxicity: None indicated (Rege, et al, 1999)

*VENTILATORY THRESHOLD refers to the point during exercise at which ventilation starts to increase at a faster rate than VO2 One’s threshold is said to reflect levels of anaerobiosis and lactate accumulation. As the intensity level of the activity being performed increases, breathing becomes faster; more steadily first and then more rapid as the intensity increases. When breathing surpasses normal ventilation rate, one has reached ventilatory threshold. Comparison studies of athletic people have shown that your ventilatory threshold occurs at a higher intensity if you are more active or have been training for that exercise


Effects of adaptogens (Cordyceps Sinensis) on lactic acid in humans:

In a double-blind, randomized, placebo-controlled study led by S. Morrissey of Beijing Medical University Sports Research Institute, researchers evaluated the effects of an adaptogen-based formula on lactic acid clearance following maximal exercise. The formulation, which included Cordycep Sinensis, was administered to 30 male subjects who were then assigned to one of three groups. The control group received a placebo, a second group received 500mg of the formula and a third group received 1000mg of the formula. Researchers took the subjects’ blood lactate measurements before exercise, at VO2 max and 15 minutes after exercise. At the end of the two weeks the group which received 1000mg/day of the formula experienced significantly improved lactate clearance (p<. 001). This trend continued through week four. Researchers concluded that lactate clearance improved due to improved lactate energy metabolism within the cell. The author concluded that using this herbal formulation would enhance lactate clearance and allow athletes greater anaerobic performance. (Burke, Edmund, 1998)

Conclusion:  Cordyceps has a long, well-documented history of use with both endurance and power athletes with strong anecdotal evidence supporting its benefits.  


Using these new findings, the 2016 Cordyceps Militaris study was able to prove positive performance enhancements with healthy human athletes using a prolonged supplementation period.  There is considerable evidence in support of Cordyceps CS-4 and with proper analytical identification of a true cordyceps sinensis, proper dose and duration, athletes can expect physiological benefit.  

Cordyceps has a multitude of mechanisms that allow it to improve bodily functions although its primary mechanism is to aid in the modulation of stress.  It is stress that both benefits athletes greatly and also derails all training and athletic gains. When stress goes unabated it quickly manifests into suppressed VO2, suppressed oxygen utilization, inflammation and poor lactate clearance.  Cordyceps is an effective natural fungus that can help athletes during heavy, stressful training.  The management of stress allows athletes to remain healthy and to sustain a high level of training.

Cordyceps Study references:

Chinese fungus and World Record Runners: American Entomologist pp. 235-236 (winter, 1994) Georges M. Halpern: Cordyceps, Chinese Healing Mushroom, Avery Publishing, 1999.

J.Zhu, G.M. Halpern and K.Jones: The Scientific Rediscovery of and Ancient Chinese Herbal Medicine: Cordyceps sinesis, Alternative & Complementary Therapies, 4(3-4),289-303,429-457.

Zhu, X. 1990. Immunosuppressive effect of cultured Cordyceps sinensis on cellular immune response. Chinese Journal of Modern Developments in Traditional Medicine 10:485-487,4540

Medicine & Science in Sports & Exercise abstract published in 2001;33:S164. Cordyceps CS-4: Poster presented at The ACSM annual meeting, Baltimore, MD, June 2001. Poster presented at The Experimental Biology 2001 (FASEB meeting), Orlando, FL, April 3, 2001.

Medicine &. Science in Sports & Exercise abstract published in 1999;31(5):S174. Cordyceps CS-4 Poster presented at The Experimental Biology 2001 (FASEB meeting), Orlando, FL, April 1, 2001. Paper published in Chinese J Gerontology 2001;20(4):297-298.

Kim H, Yun J. A comparative study on the production of exopolysaccharides between two entomopathogenic fungi Coryceps militaris and Cordyceps sinensis in submerged mycelial cultures.  J Appl Microbiol. 2005.

Chen et al,. Effect of CS-4 Cordyceps Sinensis on exercise performance in healthy older subjects. Journal of Alternative Complementary Medicine. 2010.

Akinobu Tsunoo, Naoki Taketomo, Hiroshi Tsuboi, Masayuki Kamijo, Atsushi Nemoto, Hajime Sasaki, Masyuki Uchida; Meiji institute of Health Science. Cordyceps Sinensis: Its diverse effects on mammals in vitro and in vivo. Third International Symposium of the Mycological Society of Japan, 1995.

Noboru Manabe et. Al.; Effects of the Mycelial Extract of Cultured Cordyceps Sinensis on In Vivo Hepatic Energy Metabolism in the Mouse. Japanese Journal of Pharmacology 70, 85-88 (1996).

Burke, Edmund R. Herbs Enhance Lactate Metabolism. Nutrition Science News, V.3; N.9 P. 458 (1998)

Lou Y, Liao X, Lu Y. Cardiovascular pharmacological studies of ethanol extracts of Cordyceps mycelia and Cordyceps fermentation solution. Chinese Traditional and Herbal Drugs 1986; 17(5): 17-21, 209-213.

Rege, NN et al; Phytotherapy Research; Ayurvedic Research Centre, Department of Pharmacology and Therapeutics, Seth GS Medical College, Parel, Mumbai, India. 1999 June; 13(4): 275-291.

Katie R. Hirsch, et. al. Cordyceps militaris Improves Tolerance to High-Intensity Exercise After Acute and Chronic Supplementation. University of North Carolina.  Journal of Dietary Supplements. ( 2016)

6 replies
    • Robert Kunz MS
      Robert Kunz MS says:

      great question! We, at First Endurance pride ourselves with using the latest clinical research to develop our products. Cordyceps had a wealth of research in the 70′-90’s but nothing new was being published. We came across some good clinical data on eleuthro (in the last OptygenHP formula) and decided to go ahead and update the formula using this new data. No doubt we got some strong words from some of our customers and we had some tough decisions to make. Without new data we were not comfortable simply going back to cordyceps even though some athletes requested it. In 2016 a new well designed study on cordyceps militaris was published which gave us what we needed to stay true to who we are as a brand. With this new research and with the inclusion of cordyceps militaris AND cordyecps sinensis the new formula is the best we have ever had.


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