The other day I received these questions:
- What is it about gentle extension and lateral bends that’s useful for fatigue/depression?
- And what is it about twists and forward folds that’s useful for anxiety?
Here is my answer:
First, just to be super clear – I’m not suggesting that yoga is a substitute for healthcare, but rather can support whatever care a person is already receiving.
Extensions and lateral bends are considered “Brmhana“ – that means they create some activation in the nervous system – and I’m not talking exclusively sympathetic activation of the Autonomic Nervous System (ANS). What I’m talking about is the effect of these postures on the vagal brake, which I’ll explain in a moment.
But first let me say, that I am very inspired by, practice and teach mostly breath-centric postures. I learned this kind of asana practice from my teachers in India, and also from my Viniyoga teachers, including Gary Kraftsow.
So, if you teach that way, you think about the poses as moving from the breath. And then it makes sense that postures that promote the function of the musculature of inhalation lend themselves to energizing the nervous system.
Extensions and laterals optimize the inhalation process. They activate the ANS because of their effect on the respiratory musculature (diaphragm and the external intercostals) and other apparatus (bones, cartilage, lungs, the heart, and fascial connections) of inhalation. This is why they create a more brmhana or energizing effect on the system.
Now let’s talk vagal braking. The vagus nerve is the largest nerve of the parasympathetic nervous system with ganglion close to the organs it receives and transmits afferent signals from. The vagus nerve links right into the heart, lungs, digestive track, liver, kidneys, and more and it sends messages to the brain. The brain assesses those messages and makes changes in the neuroendocrine system in order to maintain homeostasis.
When you breathe in deeply the vagus nerve acts in a way that is sort of like taking your nervous system foot off of the heart brake. The metaphor here is that when you inhale, you are coasting down a hill, and you take your foot off the brake to go a little faster. So the heart beats a little faster when you inhale NOT because your sympathetic nervous system is activated (at least at this level, it’s more complicated of course!), but because you are not pressing down on the vagal brake – not because you are gassing the SNS.
This is a great metaphor to use when explaining what happens when you inhale. Now in terms of the postures – using extensions and lateral bend postures helps optimize that process mechanically. These postures help us to inhale in a more optimal way because the muscles are more pliable. They help us to lift the metaphorical foot up off of the vagal brake in a smooth, easy way. Also, there are stretch receptors in your lungs that send feedback to the brain about respiratory and cardiac rates. Breathing deeply, fully and slowly while doing asanas stimulates these receptors as well, helping to optimize the function of the nervous system. But I’m not gonna go any further down that rabbit hole here.
So what happens when you exhale? Well, you are still coasting, but now, you put your metaphorical foot down on the vagal brake, and you slow down the cruising speed. And your heart responds by slowing down.
So why are twists and flexion postures useful for anxiety?
Twists and flexion postures are considered Langhana – reducing or relaxing. They are helpful for optimizing the respiratory apparatus involved in exhalation – the internal intercostals and the abdominals. Now, to be clear, exhalation is primarily a passive recoil of the diaphragm and lungs and that’s a good thing. Overactive exhalation is not helpful in general. So this is a subtle process and can take some time to learn. Optimized exhalation, subtle exhalation, can help people who deal with anxiety, hyperarousal, irritation, etc. because it helps to stimulate the parasympathetic response, the relaxation response via the vagal brake.
Twists and forward bends help you exhale better and better exhalation corresponds with a metaphorical foot pressing down onto the vagal brake. And that’s why they are useful for anxiety.
I hope this is helpful! Feel free to send me other questions – it gives me great ideas for blogs and I love sharing!
Want more? Check out my free guide about the science behind slow, conscious practice here –
We’re so marinated in the culture of speed that we almost fail to notice the toll it takes on every aspect of our lives – on our health, our diet, our work, our relationships, the environment and our community. – Carl Honore