Ashwagandha's Effects on Muscle Growth and Recovery

ashwagandhaWhen we think of supplements for strength and muscle building, modern options like creatine monohydrate, whey protein, or BCAAs likely come to mind. But research continuously shows that ashwagandha, an herbal supplement with ancient roots, deserves equal attention from today's performance and strength building communities. 

Ashwagandha is an herbal supplement that's been used in naturopathic medicine for centuries. It's made from the roots of the Indian Withania somnifera plant and is typically classified as an adaptogen, as it helps our bodies adapt to certain situations. In fact, ashwagandha is best known for its ability to reduce stress and anxiety and restore "the strength of a horse,” as its loose translation implies. And while these effects are well-established, its lesser-known secondary impacts on glucose, testosterone, and strength levels make it an excellent addition to your gym bag.


Cortisol is the ringmaster of stress in the body

The body is constantly reacting to stressors in the world, both physical (like from exercise) and emotional (like from deadlines at work). But regardless of its source, the body deploys the hormone cortisol to respond to stress. It's for this reason that cortisol has earned itself the nickname, "the stress hormone." 

Cortisol is a hormone that is produced by the adrenal glands and is critical for energy regulation, metabolism and immune function during times of stress. And these effects have proven to be critical in the evolution of mankind! Back when humans were living in caves, if they stumbled upon a threat (like a predator), the body would immediately produce cortisol to initiate the fight or flight response—and re-wire how the body uses energy—to best help the caveman survive. This meant breaking down muscle for energy, increasing blood sugar, and halting digestion—quite literally preparing their bodies to fight for their lives.

And in this day and age, though most of us will never be chased by predators, we have 21 Century stressors, both physical and emotional, that elicit the same responses in our bodies. And cortisol's effects prove to still be useful, despite the differences in livelihoods from our evolutionary ancestors. Cortisol's effects help us to stay wired when we're working against the clock and to be mentally sharp in high-stress situations. But these benefits come with a price.


ashwagandha cortisol studyHigh cortisol encourages muscle breakdown, fat storage, and impaired recovery

Cortisol is considered a catabolic hormone, meaning it stimulates the breakdown of muscle. This is done to increase the amount of energy available to our bodies in times of need, as the body can use amino acids (the building blocks of muscle) for fuel. However, this can negate some of our hard work and training in the gym if left unchecked. Unfortunately, it doesn’t stop there either. High cortisol levels will also slow down digestion, and, in turn, stimulate the storage of fats.

Here are a few other ways chronically-high cortisol can affect performance in the gym:

  • High cortisol levels can slow down testosterone production. When compounded with cortisol's impact on muscle breakdown, this can be crucial for gains—testosterone is an important player in muscle repair, growth and recovery.
  • Elevated cortisol prevents deep sleep. Cortisol levels naturally rise in the morning to stimulate a wakeful state. Chronically elevated cortisol can disrupt your natural sleep/wake cycle and ultimately prevent the body from entering restorative deep sleep and contributing to fatigue.
  • Increased cortisol suppresses the immune system. High levels of cortisol will slow down immune function, making us more susceptible to getting sick and preventing recovery after hard workouts.

Ashwagandha improves cortisol-mediated effects plus other measures of muscle building

Scientist haven’t yet nailed down the exact mechanism of action for ashwagandha's impact on cortisol, but the practical evidence of its usefulness is from a large and robust body of scientific evidence. As we just mentioned, elevated cortisol can be an archenemy for muscle building, so it's in our best interest to keep cortisol levels low—which is exactly where ashwagandha can help. But in fact, recent studies have shown that this herb's effects on strength and power aren't just cortisol-dependent: 


  • It can indeed decrease serum cortisol by up to 27% [1]
  • It also has contributed to a 17% increase in total testosterone [2]
  • It displays increases in raw strength, muscle size and VO2 max [3-5]
  • It helps to lower LDL (bad) cholesterol, blood glucose, triglycerides and hsCRP [6]
  • It can increase HDL (good) cholesterol and DHEAS [6]

All in all, ashwagandha is proven to be effective at mediating the negative effects elevated cortisol has on our strength, as well as lots of other important markers in the body. While ashwagandha can’t remove the stresses from our lives, it can certainly help us cope with them. Keeping an eye on your cortisol levels and having an arsenal of solutions that work with your lifestyle will help you stay strong all season long.


recovery supplement

Read this before you try ashwagandha

Before you add ashwagandha to your supplement regimen, there are some circumstances that you need to consider. There have not yet been studies on the effects of ashwagandha in expecting mothers, so if you’re pregnant, best hold off on adding this to your supplement plan. And since the W. somnifera plant is a close relative to the nightshade family, those who are allergic to nightshades should avoid ashwagandha at all costs. As with all supplements, always speak to your healthcare provider before incorporating anything new into your regimen. You should always consult your doctor, your bloodwork, or both to understand which supplements and dosages are right for you.



6. Auddy, Biswajit et al. A Standardized Withania Somnifera Extract Significantly Reduces Stress-Related Parameters in Chronically Stressed Humans: A Double-Blind, Randomized, Placebo-Controlled Study. (2008). JANA 11(1):50-56

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