Cordyceps, an increasingly popular exercise enhancing supplement – whats the safety and efficacy like?

Recently, I’ve noticed an increasing number of my friends back in Canada and the States taking a supplement containing Cordyceps sinensis, which is purported to be an exercise enhancer. Being curious (and, as with most exercise enhancing supplements, suspicious), I decided to peruse PubMed and other databases for studies looking at the action of Cordyceps in terms of exercise endurance.

Cordyceps Campanotus

As a fairly new sports supplement, studies on exercise endurance with Cordyceps sinensis have only been published from the late 1990’s. While they are all double-blinded, randomized controlled trials, the majority of them have fairly small sample sizes. Three of the six trials I found stated that Cordyceps supplementation improved exercise endurance, either through work output, time to complete a set exercise, VO₂ max, or increased ventilatory and metabolic thresholds, as shown through blood lactate levels.^1,2,3 Conversely, three trials found no change in peak power output, time to exhaustion, peak heart rate, blood lactate, ventilatory threshold, respiratory compensation point, VO₂ max, or muscle tissue oxygenation saturation.^4,5,6

As previously mentioned, almost all trials were of a low power, involving less than 30 participants each, barring a trial by Zhu and Rippe that reported significant results; however, this trial was funded by the company that produces CordyMax, so there may be bias in their results.² The other two trials that found a positive relationship between supplementation and exercise endurance were not published as full journal articles. Trials reporting improved exercise end-points had given participants 1-3g/d of Cordyceps for 6-12 weeks, and those with non-significant findings had given participants 1-3g/d of Cordyceps for 1-5 weeks.^1,2,3,4,5,6 Another important point to note is that the subjects from the three trials with significant findings were male and female, aged 50-75y, whereas the three trials that did not report significant findings studied healthy males aged 18-50y, and amateur male athletes.^1,2,3,4,5,6 If Cordyceps does improve exercise endurance, perhaps it only makes a significant difference if taken for a longer period of time, and in those who are not already reaching peak levels of cardiovascular fitness.

Bottom line: there have not been enough high-power trials to draw a concrete conclusion in relation to the effect Cordyceps sinensis may have on exercise endurance. In any event, toxicity studies of a similar strain of Cordyceps on rats did not yield any adverse effects (they were given 5.33g/kg/day of Cordyceps guangdongensis for 13 weeks),⁷ and none of the aforementioned trials reported any adverse events, so if you do decide to give Cordyceps a try, it is unlikely that you would experience any side effects.

If you have tried a Cordyceps supplement, please let us know, and tell us if you’ve found it effective (or not)!

Cordyceps supplement

On a side note, a number of studies are being conducted on Cordyceps sinensis looking at potential anti-organ-rejection, anti-cancer, and immunopotentiation effects.

1) Chen S, Li Z, Krochmal R, Abrazado M, Kim W, Cooper CB. Effect of Cs-4 (Cordyceps sinensis) on exercise performance in healthy older subjects: a double-blind, placebo-controlled trial. J Altern Complement Med. 2010 May;16(5):585-90.

2) Zhu J, Rippe J.CordyMax enhances aerobic exercise capacity and metabolism, and endurance performance in healthy, mid-age to elderly, sedentary humans. FASEB J. 18(5):A931. 2004.

3) Xiao YX, Huang Z, Chen G. Increased aerobic capacity in healthy elderly humans given a fermentation product of cordyceps Cs-4. Med Sci Sports Exerc.1999;31:S174.

4) Colson SN, Wyatt FB, Johnston DL, Autrey LD, Fitzgerald YL, Earnest CP. Cordyceps sinensis- and Rhodiola rosea-based supplementation in male cyclists and its effect on muscle tissue oxygen saturation. J Strength Cond Res. 2005 May:19(2):358-63.

5) Parcell AC, Smith JM, Schulthies SS, Myrer JW, Felingham G. Cordyceps sinensis (CordyMax Cs-4) supplementation does not improve endurance exercise performance. Int J Sport Nutr Exerc Metab. 2004 Apr;14 (2):236-42.

6) Earnest CP, Morss GM, Wyatt F, Jordan AN, Colson S, Church TS, Fitzgerald Y, Autrey L, Jurca R, Lucia A. Effects of a commercial herbal-based formula on exercise performance in cyclists. Med Sci Sports Exerc. 2004 Mar;36(3):504-9.

Yan WJ, Li TH, Lin QY, Song B, Jiang ZD. Safety assessment of Cordyceps guangdongensis. Food Chem Toxicol. 2010 Nov;48(11):3080