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Yoga Nidra – an age-old bio-hack

yoga teacher tashi dawa shala nidra yogaIf you’ve ever practiced Yoga Nidra you’ve probably noticed that even a half an hour session feels more like a couple of hours of decent sleep. Of course sometimes as soon as the teacher invites us to relax we drop off to sleep so it just seems like a great power nap but even then the Yoga Nidra practice seems to offer very particular rejuvenation. The harmonising effects of the practice can leave us feeling so restful, so intimate, so delighted and relieved.

Research suggests the reason this age-old practice is so efficient at providing rest relates to the way we surf across brainwave states.

Even though it’s commonly thought that the practice was pioneered by Swami Satyananda Saraswati according to Yoga Nidra specialist James Reeves the practice can be traced back as far back as 1000 BC from Sankhya Philosophy in Ancient India.

The practice was certainly popularised though by Satyananda who describes the Yoga Nidra practice as “reaching the border between waking and sleeping states.” He refers to what we might also describe as playing across brainwave frequencies.

Brainwaves are a measurement of brain activity produced by synchronised electrical pulses as masses of neurons communicate with one another. These frequencies can be measured using an EEG (electroencephalograph) which can be used to determine patterns of imbalance.

We don’t need an ECC to know whether we are experiencing a balance though because we can feel it. It’s one of the most intimate experiences, our feeling of a sense of ease is an indication of brainwave harmony and feeling ill at ease may indicate disharmony. Is there are a way to create harmony and experience the birth-right of peace of mind? Well yes, it appears that there is…


Tashi theta-binaural-beats kaliyoga retreatsAccording to Brainworks, who are among the first neuro-feedback practices in the UK, we could think of brainwaves as musical notes – ‘Like a symphony, the higher and lower frequencies link and cohere with each other through harmonics.’

When we feel mentally sluggish and sleepy the speed (measured in hertz or cycles per second) would measure as slower or lower and when we feel over-stimulated they measure as faster or higher.

Long term meditation and yoga, especially yoga nidra, can train the brainwaves into a state of balance which is why we love it so much… it just feels so good!


So what happens to us our brainwaves during a yoga nidra session?

When we begin the nidra practice we are in what is called the beta state. The beta state (12 TO 38 HZ) is when we are awake to the world around us and are able to process what’s happening and understand loads of information.

Continuous high-frequency processing at the beta state takes an enormous amount of energy and is inefficient for the brain over long periods. We get tired if we try to remain alert and engaged in problem-solving for too long. As you are reading this you are experiencing the beta state in order to process the information.
We begin a Yoga Nidra session by lying down and getting as comfy as possible, we commit to staying still for the duration of the practice and we might be asked to set a resolve, called a ‘sankalpa’.
The ‘sankalpa’ is a kind of affirmation practice which can be developed in many ways. For example, we might be guided to ask ourselves about our present desires beyond mere daily cravings and often we might find quite quickly the desire for love, for peace of mind, for forgiveness. Having identified our heart’s deeper longing we form a short sentence in the present tense as though it’s already true… ‘I am forgiven’, ‘I feel loved’, ‘I feel at peace’ and repeat the phrase to ourselves a few times.
Next, we are guided through a body scan to focus on various subtle sensations like the feeling of the tongue in the mouth, the air on the skin. This scan triggers the first brainwave shift. The first change we experience is simply called the relaxation response as brainwaves alter from the mentally alert waking state of beta towards the slower frequency known as the alpha state (8 TO 12 HZ) which is slower and more relaxed.
Knowing how to easily shift to the alpha state is a helpful relaxation tool and may be easily accessed as long as we are not over-stressed perhaps blocking the alpha state. If you’re curious and would like to take a moment to experience the shift from beta to alpha state we could take an ‘alpha break’ now. No guarantees but if you want to try this exercise it may work quite quickly for you. Sit back a little, and in a moment close your eyes and take 3 deep breaths counting the inhale for 4 seconds and then exhale for 6 seconds then take your time to open the eyes again without rushing… Hello again… Did you notice any change? You might have felt the subtle shift of as though you were powering down, shifting inner gears towards a more neutral state. That’s the experience from beta to the alpha frequency.. pretty cool huh?

During alpha brainwaves, the hormone serotonin is released and we start to feel calmer and more at ease. At this phase of the Yoga Nidra practice, we still feel lucid yet we might enjoy a slightly diffused awareness. Neural integration occurs now as the hemispheres of the brain become more balanced.

We continue to scan the body and delve even more deeply into the Alpha frequency range, maybe feeling the bio-rhythms of breathing and the pulsing blood flow.

There is a whole range of visualisation techniques that might be used during the next stage of the practice, suggestions that warm light is filling the body, changing bodily sensations, such as feeling hot, cold, heavy, light.

At this stage, we might go from a deep alpha state towards a high theta brainwave state (3 TO 8 HZ) known to us as the dream state or REM sleep state.


yoga and meditation kaliyoga retreatsSo now we start to feel withdrawal from the outside world. Theta waves are linked with the much celebrated ‘flow state’, that elusive, hypnotic state associated with peak performance. During theta brainwaves, our senses are withdrawn from the external world and focused on the inner world, in yoga we call this pratyahara.

This is one of life’s deeper pleasures that we experience a few moments as we drift off to sleep or as we first wake up. We might also experience the theta waves during our meditation practice if we are persistent. Theta brainwaves are said to be our gateway to learning, memory, and intuition.

The task now is to remain for as long as possible there without speeding up to the waking or beta state but also not to drop into a deep sleep. The guide is likely using a regulated vocal tone and speaking pace in order not to disturb and commonly listing images like open skies, snowy mountains, a burning fire, sun glistening into falling water or guiding journeys across imagined environments,..


Exploration – who are you?

It’s at this point we might refer back to the ‘sankalpa’ the inner resolve and plant it like a seed of light into what is now an open and receptive mind field.

James Reeves says he uses this opportunity to encourage an exploration of the nature of consciousness. ‘Do you know who you are? Are you aware of your true nature? Do you know what it is to be sentient?’ He says that ‘Yoga Nidra enables us to dive in and recognise our Self as open, expansive, unbounded, unlimited awareness.’

By this stage, we might have even slowed the brainwaves further into the delta waves (.5 TO 3 HZ), a deep, restorative, dreamless slumber. This is the said to be a deeply restorative state where even the organs can regenerate and the stress hormone cortisol might be removed from the system.

Long-term meditators might reach this state even though they are totally lucid but most of us reach this only during deep, dreamless sleep.

It’s during these slower brain wave states that the long term healing effects can be experienced, where harmony and balance can be restored. Yoga Nidra techniques are being used for this reason for serious trauma and stress relief. It’s due to this ability to surf the brainwaves and harmonise the frequencies that a regular practice of yoga nidra is said to be a wonderful support for inner peace.





yoga teacher Kaliyoga retreats shala yoga nidraAt the end of a yoga nidra session, we’d be guided gently back to the waking state, back to physical sensations and then becoming aware of lying in the room. Eventually coming back to the waking state.

We may not remember the whole experience as we might have slipped in and out of conscious listening and awareness but it doesn’t seem to matter, the process works anyway.


Then there might be a terrific afterglow, perhaps the feeling of relief as well as a good rest, perhaps even an experience of a joyful presence. It’s at this moment we can feel the effects of the practice, upon waking all of the issues we face, deadlines and obligations return but we might perceive them differently.

Reeves says that some of the most positive effects of the practice of Yoga NIdra are that we become ‘able to welcome and respond to thoughts, feelings, and beliefs in new ways. From this deep, underlying sense of ease we might effectively meet our uncomfortable memory or trauma and through deep listening and welcoming, come to new understanding or resolution.

In our gloriously busy and arguably stressful modern culture, it’s likely very few of us are spending much time in the healing theta and delta frequencies and may be missing a great opportunity for deep restoration of balance.

So beta brains, need a break? try some nidra yoga…


References and Further reading

James Reeves




Swami Satyananda Saraswati

A Systematic Course in the Ancient Tantric Techniques of Yoga and Kriya, Bihar School of Yoga, Yoga Publications Trust, 1981

Tashi Dawa has been one of Kaliyoga’s beloved resident teachers for almost 10 years and teaches regular retreats in Italy. She offers a variety of practices during the weeklong retreats including Yoga Nidra, meditation, and dynamic yoga flows. She also offers mentorship programs for those who looking for practice immersions. Join Tashi in Italy at Kaliyoga Retreats from May – August in 2019.