Ashwagandha is considered an adaptogenic herb and its consumption is typically connected with reduced anxiety, improved sleep, and reduced cortisol levels. Some recent studies are also suggesting that it may have positive effects on strength and endurance performance. Unfortunately, there are very few studies on the topic and most of them are very short in duration and poor quality.
Ashwagandha’s effects on VO2Max
The first study looking at the effects of Ashwagandha on athletic performance was published in 2010 in a journal called the International Journal of Ayurveda Research. There are many issues with this study but probably the most notable one is tied to its most important measurement, oxygen uptake. The peak oxygen uptake values (also known as VO2Max) in the study improved from 13,54 to 14,47 ml/kg/min in those taking the Ashwagandha supplement. This is highly concerning considering that VO2Max for an average untrained person during exercise is typically between 30 and 40 ml/kg/min. Achieving a peak oxygen uptake of 14 ml/kg/min would suggest that the person is either resting or taking a very slow walk. That’s hardly a relevant finding to athletic performance, or anything else really.
Ashwagandha and a 7.5-km cycling time-trial
A different study from 2018 tested the strength as well as the aerobic performance of recreationally trained subjects. The study was designed as a randomized, double-blind and placebo-controlled trial and the endurance was tested on a 7.5-km-long bicycle ride. Unfortunately, after 12 weeks of 500 mg of Ashwagandha or a placebo, the findings of this study were not statistically significant when it comes to cycling. That would not be a problem, it happens in a lot of research.
The issue is that the average baseline times for this 7.5-km time trial were close to 20 minutes. That means they were riding at a speed of around 22 km/h. The study said that the participants were instructed to complete the course “as quickly as possible”. It’s hard to imagine a healthy young person riding that slowly during a short time trial on a stationary ergometer under these instructions. This again brings the quality of this study into question.
Will ashwagandha improve your cycling performance?
There is a 2021 meta-analysis of 12 studies, which concluded that ashwagandha was more efficacious than placebo for improving variables related to physical performance. This may sound encouraging until you realize that this meta-analysis includes the strange study from 2010 mentioned in this article. Knowing just that, you have to take these findings with a pretty sizeable grain of salt.
Overall, the evidence that ashwagandha positively impacts endurance is at the very least questionable. Until we have some high-quality peer-reviewed studies on the efficacy of ashwagandha, we can’t really say much for sure. So, if you see a company marketing the supplement with the promise of improved VO2Max or endurance, approach with caution and scepticism.