The Yang reinforcing quality of Cordyceps expresses itself by increasing the cellular (mitochondrial) energy production and partly by reducing oxidative stress and improving glucose metabolism. Several human studies, including one placebo-controlled study of older people with chronic fatigue, confirmed that Cordyceps increases vitality. Symptoms such as fatigue, cold intolerance, dizziness, tinnitus and memory problems significantly decreased with use of Cordyceps, compared to the control group. In another placebo-controlled study of healthy elderly people, endurance and maximum oxygen capacity significantly increased during exercise (cycling on a stationary bike) after the use of Cordyceps.
A simple and reliable method to see if a preparation has an effect on endurance and fatigue, is to conduct an animal experiment. It may sound cruel, but it is real proof. In an experiment in which mice are forced to swim until they are completely exhausted, it can be measured if mice that have received a supplement have greater endurance. This test used supplementation with a (hot) water extract of Cordyceps sinensis (rich in polysaccharides) to significantly increase endurance and decrease fatigue, partly by improving stress tolerance. The acute stress situation led to the control animals increasing pressure on the adrenal glands and reducing the size of the liver, spleen, thymus and thyroid functions. In the animals that received cordyceps extract, no effect was measured on the stress scale and the weight of these organs. In other words, despite the incredible stress of being to swim for their lives, mice did not react adversely to stress becasue of Cordyceps sinensis. Image all the stressed out people out there… Imagine how good it would be for their health to take Cordyceps sinensis!
Cordyceps sinensis can also benefit people by improving energy production, antioxidant uptake, immunocompetence and stress resistance to delay the aging process.