June is the month of yoga nidra (pt2)

It's pretty good for you, it seems

It’s basically almost exactly 5 years ago: June 2020, 3ish months into the pandemic and severe lockdowns that meant that our only interactions with the world were Zoom meetings and daily walks in the park (sometimes alone, sometimes with others). Some people spent their extra time drinking wine. I did lots of yoga teacher trainings, because, why not? What else am I going to spend my money on, and what better time to train now that all is online too?

I did four advanced and specialised yoga teacher trainings in 2020, and the first one that really changed me and catalysed my interest in the science of yoga was training to lead a type of guided and relaxing meditation called yoga nidra (check it out here).

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WTF is it then?

Like most of the yoga we practice today, yoga nidra is a modern invention (mostly from then 60s and 70s), and draws inspiration from many traditions beyond yoga, including early 20^th century psychology. A yoga nidra session will typically involve a phase of scanning through the body, a phase of focusing on the breath and some kind of visualisation exercise, although the exact mix will vary depending on the teacher and school they follow.

The training was a long weekend of learning and practice, and was probably the most relaxed and creative I’d felt in years. A yoga nidra experience feels like you are being immersed into the softest blanket, probably one made of cashmere, and stroked softly with duck feathers. Your whole body relaxes, your mind slows down, and you feel a sense of calm like you have no worries in the world. If you’ve never tried it, then please stop reading right now and go online and find a yoga nidra practice to try out immediately (here’s my Insight Timer page). If you still disagree, then well, let’s celebrate our differences.

My point is, it’s an incredibly relaxing experience, and incredibly relaxing experiences, as you can imagine, can help you feel calmer and less stressed. Which made me desperate to find out if there was any science behind it. The interesting thing about yoga nidra is that it’s actually not well-studied at all, which meant that someone determined could very easily tackle the whole of the available literature into the science of yoga nidra in one or two days max. Which is basically exactly what I did, and have been doing ever since (the rate of publication hasn’t exactly sped up since).

A short pause here

Although yoga nidra is a creative practice for the teacher, which means that they can write interesting and explorative scripts inspired by all sorts of things and designed to achieve all sorts of things, it is more or less a recipe of similar ingredients. Which, I think, makes it a little more easy to draw general conclusions about it than the broad church of the label yoga.

For those stressful times

One of the people who is interested in the effects of yoga nidra on our health and wellbeing is Carola Charipenello, a yoga therapist who fell in love with science to the point of deciding to self-fund an MSc in Neuroscience and now a PhD at King’s College, in London. I notice Carola’s call for research participants on the various yoga Facebook groups I’m in and I am immediately excited, and actually a little jealous; a few years ago I tried to get some funding from a well-known wearables company to study the effects of yoga nidra on mental health, but they were not interested, and well, life and other things happened and I never pursued it further.

I meet Carola on a Teams call, eager to hear more about her work. Her confidence is in stark contrast to how I felt when I was doing laboratory research and talking about my work, but I guess that’s what happens with age and experience. She reminds me how little money they is to fund this kind of work, and how she has had to beg and borrow from everyone to be able to do the work. I made money before that, she jokes, very aware that there is very little to be gained in this space. But so far, the findings are good. In her small, pilot study she’s found that yoga nidra has shown beneficial effects for those living with excessive stress.

Her work is consistent with what others are finding. A few years ago a group of scientists in Germany carried out the largest study I’ve ever come across in this field, and certainly the largest study on yoga nidra, with around 700 participants. What this study showed was that practicing yoga nidra made participants feel more positive about life, less stressed, more satisfied with life and generally less negative. Participants also reported feeling more mindful. This is all compared with baseline, which means before the intervention started, and also compared to a control of doing nothing at all.

This is great news because it means that yoga nidra can help to make us feel better from a mental health perspective, and definitely better than doing nothing at all.

What was even better news was that in this study they tested the effects of a short form of yoga nidra, just 11 minutes long – yoga nidra practices tend to be between 20 and 30 minutes, which can sometimes make them less practical to include in out daily lives, so the scientists specifically wanted to test whether a practical version of yoga nidra would be effective.

This practice included the body scan and breath awareness, which are the first parts of the typical yoga nidra practice. And participants didn’t have to attend live sessions, they could use recordings to listen to when it was most convenient for them. And they didn’t even have to practice every day to see the benefits. This is why I love this study – it didn’t place huge demands on people’s time. You don’t want to make yourself more stressed by trying to find time to practice.

The follow-up study, which I wrote about last month, actually reported reduced levels of the stress hormone cortisol. This is a commonly used proxy for measuring stress levels in a more physiological way (ie not simply asking people if they are feeling stressed and how stressed they feel). The reduction in cortisol was tied to longer practices though, so it might be that the longer you practice, the bigger the effects. But that doesn’t take away the benefits of the 11 minutes practice.

There is other research that has also found that yoga nidra can help us feel less stressed, including research among specific groups of people like college professors and nurses.

Looking beyond stress

So that’s stress, but what about other mental health conditions like anxiety and depression? Does yoga nidra have a positive effect?

I’m going to give a tentative yes, although I want you to remember my usual disclaimer – yoga nidra is just as guilty of the same design flaws as most yoga studies, if not more so.

When we look at anxiety, I think the evidence is a little more convincing that yoga nidra could be helpful. There has been some research on the effects of yoga nidra on specific work populations, like college professors. The college professor study also looked at anxiety, and found that in addition to reducing stress, yoga nidra reduced anxiety in this group too. This is after 3 months of practice. It was also more effective than doing nothing at all during the 3 months, which is what we call the control group. Interestingly, yoga nidra was actually better at reducing anxiety that the mindfulness meditation group, at least in this study. So there are potentially benefits to trying out yoga nidra, alongside what you are already doing, if anxiety is something you are living with at the moment.

Looking at depression, the evidence is mixed. In one study looking at the elderly, yoga nidra helped to reduce depression, but it wasn’t better than just listening to music so that makes it a little less convincing. Participants also had to practice every day, which isn’t very practical. By contrast, the study that came out this month found that the 11-minute yoga nidra was better than music at reducing depression.

But really, how?

Carola’s research will try to understand a little more about what it is about yoga nidra that helps us feel less stressed and/or alleviates some of the symptoms of anxiety and depression. One hypothesis I have is that it’s, again, related to the activation of the vagus nerve, and the associated activation of the parasympathetic nervous system. This might happen through the natural slowing down of the breath that accompanies any kind of guided meditation.

There is also some evidence that yoga nidra could drive changes in brain chemicals, called neurotransmitters, which might, at least in part, explain these effects. For example, a fairly old (and incredibly small) study that no one else seems to have tried to replicate since found some increases in dopamine. But anything I share here is hypothetical as no one has actually done this research for yoga nidra yet.

Carola is keen to understand other aspects of this, like the neuroscience that might explain the beneficial effects on our mental health. She’s managed to get some small funding to look at what happens to our brains during this practice, using various brain imaging techniques like an electroencephalogram, or EEG, and an MRI to measure brain activity. The idea is to look at how brain activity, and brain plasticity (the brain’s ability to change its responses to external stimuli) changes after a period of yoga nidra practice. This is especially relevant in the context of managing depression and anxiety, where persistent behavioural patterns might be contributing to the condition’s symptoms.

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I volunteer to join Carola’s pilot study. Unfortunately for me, I am rejected. Apparently, my existing experience means I am not eligible as my brain (and immune system) has probably already been somewhat shaped by my existing yoga nidra practice. Instead, we agree that I’ll lend her my immunology expertise when the next phase of the research comes out.

No long post next month, back in August with more content. Enjoy!