Qualitative Impressions of a Yoga Nidra Practice for Insomnia: An Exploratory Mixed-Methods Design

Abstract

Introduction:

Insomnia affects up to half of the U.S. population, and due to limitations of current treatments, there is a growing interest in mind–body practices to reduce insomnia. To understand how a guided meditation practice, Yoga Nidra, may affect relaxation and align with current descriptions of nonpharmaceutical practices that could improve sleep, qualitative and quantitative methods were used to explore participant experience of a single Yoga Nidra practice, administered in a group setting.

Methods:

Current insomnia (Insomnia Severity Index), sleep practices, and mood (positive and negative affect schedule [PANAS]) were measured at intake. After 30 min of Yoga Nidra practice, the PANAS was readministered. In a focus group that followed, participants discussed their experience before, during, and after the practice and the likelihood of repeating it. Six groups were conducted. All interested adults were welcome to join.

Results:

In the final sample of 33 individuals (79% female), 80% of participants reported insomnia at intake and 45% reported a regular mind–body practice, supporting the prevalence of insomnia in the society as well as the interest in mind–body practices. After the Yoga Nidra intervention, mean negative affect decreased 5.6 ± 4.5 points, a 31% decrease from baseline, and positive affect decreased 3.5 ± 9.7 points, a 13% decrease. Three major themes were identified from focus group discussions: response to the practice (relaxation, perceived sleep, and sense withdrawal); factors that affect engagement (delivery method and intrapersonal factors); and potential as a clinical intervention (for conditions including sleep, anxiety, and pain).

Conclusion:

Yoga Nidra appeared tolerable within the sample, and descriptions suggest it may be useful for enhancing relaxation, facilitating sleep, easing anxiety, and reducing pain. Results from this study will inform the design of future studies of Yoga Nidra for insomnia and related conditions.

Introduction

Insomnia affects between 30% and 50% of the U.S. population and is defined as difficulty with sleep initiation, duration, consolidation, or quality that leads to daytime impairment.^1,2 Insomnia is associated with increased risk of depression, heart disease, stroke, and mortality from these conditions.^3,4 Current treatment options for insomnia include pharmacotherapy, cognitive behavioral therapy, and sleep hygiene (e.g., dark room, low temperature, and no screens).^5–7 Despite available treatments, the prevalence of insomnia remains high. Behavioral interventions have demonstrated only modest effects and are limited by the need for trained professionals to deliver the intervention, as well as delayed response time.⁸ Pharmaceutical treatments are limited by cost, the need for ongoing treatment, and side effects such as daytime impairment and risk of overdose.^6,7,9–11 Thus, there is a need to identify additional effective and accessible treatments for insomnia.

Yoga Nidra is a guided meditation practice representing a distinct limb of Yoga, called Pratyahara, or “sense withdrawal.”^12,13 During the practice, awareness is gradually focused away from the body and guided through the sense of hearing. The practice of Yoga Nidra may be a promising treatment for modern-day insomnia because it is a passive audio-guided practice that can be easily delivered through digital recording for home practice. Prior research on Yoga Nidra has evaluated changes in brainwaves¹⁴; hormones¹⁵; neurotransmitters¹⁶; and perceived effects on pain,¹⁷ stress,^18–22 anxiety,²³ sleepiness,^24–26 and sleep quality.^19,25,26 Yet, to the authors' knowledge, while Yoga Nidra has been demonstrated as having potential to affect sleep quality, as a secondary outcome, in studies on program development for veterans,¹⁹ and on depression in older adults,²⁰ this practice has not been directly investigated as an intervention for insomnia. In addition, the changes in consciousness produced during the practice of Yoga Nidra have been very minimally researched,²⁷ and thus, an investigation of participant experience would fill an important void in the literature.

The purpose of this preliminary study was to qualitatively investigate the relaxation effects of a Yoga Nidra practice, to understand its potential applications as a tool for addressing insomnia. In particular, the goal was to explore participant experiences of a single Yoga Nidra practice, the credibility of Yoga Nidra as a therapeutic intervention, and potential barriers to trying Yoga Nidra again, in a class or independently, using an exploratory qualitative design and thematic analysis.

Methods

Recruitment

This study was approved by the institutional review board of the National University of Natural Medicine. Participants were recruited between January and December 2018 using a combination of public ads (flyers and online advertisements), and purposive and convenience sampling to identify participants. The authors aimed to recruit as broad a sample as possible (with and without insomnia, mind–body experience, and/or academic backgrounds), and anyone over 18 years was welcome. All participants provided informed consent and were then invited to participate in a 30-min Yoga Nidra practice followed by a focus group discussion.

Participants

Six focus groups were held in three states (New York, Oregon, and Hawaii). The final sample included graduate students, academic researchers from two universities, community members at a Yoga center, and incarcerated women. The researcher working with incarcerated women went through safety and security clearance and offered Yoga Nidra during an existing timeslot for yoga, meditation, and/or prayer for women only (and thus, men were not included). Graduate students and some researchers were from the same university as the researcher, but were not her students or employees. The researcher leading focus groups at the yoga center was a teacher there. And lastly, researchers had no previous relationship with the co-op that hosted a focus group. All participants were informed of the researchers' interest in Yoga Nidra for relaxation and how it may relate to sleep, and that these researchers also taught Yoga Nidra.

Instruments

Insomnia Severity Index

The Insomnia Severity Index (ISI) is a 7-item questionnaire that assesses insomnia symptoms over the previous 2 weeks.²⁸ Items are rated using a 5-point Likert scale, and total scores range from 0 to 28, characterizing insomnia severity (from none to clinically severe) in 7-point categories. The ISI is a reliable and valid instrument for detecting insomnia in a community sample (Cronbach's α = 0.90²⁹).

Positive and negative affect schedule

The positive and negative affect schedule (PANAS)³⁰ consists of 20 self-report items divided into two subscales, positive affect (PA) and negative affect (NA). Respondents rate “to what extent you feel this way right now” using a 5-point Likert scale. Scores range from 10 to 50 on each subscale, and higher scores indicate higher levels of PA or NA. The PANAS is a reliable and valid instrument for measuring mood in a community sample (Cronbach's α = 0.89 [PA] and 0.85 [NA]³¹).

Study procedures

Participants completed an intake survey containing questions addressing demographics, sleep hygiene practices (i.e., behaviors used to encourage sleep), insomnia evaluation (via ISI), and assessment of mood (via the PANAS). Participants then practiced one asana (yogic posture) involving lying on the back and pulling knees into the chest (pawanmuktasana or “wind-release pose”). This asana was chosen to release tension in the back and body, while also being accessible for people of most ages and abilities. Participants then practiced 30 min of Yoga Nidra as a group, lying on mats (or sitting in chairs as needed) and listening to a recorded Yoga Nidra meditation. After the practice, participants completed the PANAS and then participated in a focus group discussion.

Yoga Nidra script and recording

For this study, a traditional Yoga Nidra script written and recorded by Satyananda Saraswati was used.¹² A typical Yoga Nidra practice includes a series of short activities, each lasting ∼1–5 min and including (but not limited to) settling into a lying position (shavasana), setting a resolution (sankalpa, or personal goal), rotation of consciousness (cycling awareness quickly through the body), breath awareness (pranayama), experience of opposites (hot/cold, heavy/light), visualizations (guided imagery), and the return to body awareness and the resolution. The recording used in this study is publicly available online (https://www.youtube.com/watch?v=jPTRzOxmbZ8). In general, Yoga Nidra is practiced regularly (weekly, e.g.), as an ongoing part of a healthy routine. In this study, however, the focus is only on the first impressions of a single practice, from participants representing as broad of a population as possible, to understand how it is received, and how/if they may envision utilizing it in the case that they ever experience sleeplessness.

Focus group procedures

For each focus group, the moderator followed a semistructured guide with scripted questions, available in the Supplementary Information. E.S. (PhD) moderated the focus groups in Oregon and comoderated the focus group in New York (in collaboration with a teacher who was well known at the jail), while a student collaborator (masters student, Kristen Sprague, who is listed in the acknowledgments) moderated focus groups in Hawaii. E.S. received a training in qualitative research, and instructed KS (Kristen Sprague, the masters student mentioned above and in the acknowledgments) on the process. Participants were asked about their experience during the practice, how they felt after the Yoga Nidra practice compared with before, whether they experienced any challenges during the Yoga Nidra practice, what they recalled from the script (to probe for awareness during the practice and/or occurrence of sleep or dreaming), and whether they felt they could and/or would repeat the practice again, including at home if help with sleep was ever needed. Each focus group lasted 30–60 min in total.

Analysis

Descriptive statistics were calculated for the study sample, including age, gender, experience with mind–body practices, insomnia severity, and existing sleep hygiene practices. The authors assessed whether baseline PA and NA subscale scores changed after the Yoga Nidra intervention using a t test for paired values. Analyses were conducted with Excel and STATA v15.1.

A facilitator took notes during the focus groups, which were audio recorded and transcribed verbatim. Participants were made aware during consent that they would be recorded. Three authors (E.S., D.T., and B.W.) conducted a thematic analysis³² in the following stages. First, transcripts and notes were read multiple times by all three researchers to familiarize themselves with the data. Next, two authors (E.S. and D.T.) independently conducted inductive coding in duplicate using Dedoose v8.3.17. Any discrepancies were managed through discussion until consensus was reached. After coding was complete, three researchers (E.S., D.T., and B.W.) grouped codes into meaningful conceptual themes until data saturation was reached (all codes fit into a major category). Finally, researchers examined the full extent of quotations coded into each theme to synthesize and provide a description of the theme's meaning, and selected quotations that best illustrated that description. A COREQ Checklist for this study is available in the Supplementary Information.

Results

Sample description

Demographic characteristics of the focus group participants are presented in Table 1. A total of 33 people participated across six focus groups. No one who attended a Yoga Nidra session refused participation in the study. Participants included 12 academic researchers in Oregon, 2 graduate students in Oregon, 11 community members in Oregon and Hawaii, and 9 incarcerated women in New York. The majority of participants (80%) had some level of insomnia, with 43% reporting symptoms consistent with clinical insomnia. Of note, 100% of incarcerated individuals in the study reported some level of insomnia. Forty-five percent of participants reported regular mind–body practices (which were more popular among community-dwelling [58%] vs. incarcerated [11%] adults).

Table 1.

Demographic Characteristics of N = 33 Focus Group Participants

Age
Mean (SD)	38 ± 12a
Range	19–60+
Gender, %
Female	76
Male	21
Not indicated	3
Current mind–body practice,b %
Yes	45
No	52
Not indicated	3
Duration of mind–body practice, if present %
“Years”	20
1–10 years	27
10–20 years	20
>20 years	20
Did not specify	13
ISI (n = 30), %
No insomnia	20
Subthreshold	37
Clinical (moderate)	40
Clinical (severe)	3

^a Twenty-three respondents, with one indicating 60+, which was calculated as 61 years.

^b Mind–body practices included yoga, meditation, prayer, qigong, dance, moving meditation, mindfulness for community-dwelling adults, and occasional yoga/meditation.

ISI, Insomnia Severity Index; SD, standard deviation.

Participants reported factors that generally impair or encourage their sleep (Figs. 1 and 2). The most commonly reported factors that impair sleep included overactive thoughts, anxiety, and stress. Commonly reported practices that promote sleep included limiting lights, performing certain activities during the day (such as less caffeine, more exercise) and before bed (relaxing activities like reading, baths, and down time), and controlling the sound and other atmospheric elements in the room.

FIG. 1.

Factors that impair sleep. Factors that impair participants' sleep were compiled from free responses on the intake survey. Physical sensations that impaired sleep comprised the following participant responses: mattress firmness, sore back, congestion, and fibromyalgia. PTSD, post-traumatic stress disorder.

FIG. 2.

Sleep hygiene practices and factors that promote sleep. Results were compiled from participants' free responses on the intake survey. Responsible daytime activities included regular exercise, eating well, completing tasks, light box in morning, bed reserved for sleep, and limiting caffeine. Atmospheric control included dim light, no clock or TV, sleep mask, firm mattress, and hot water bottle. Prebed relaxation included showers, salt baths, soft music, affectionate touch, and down time. Medications and supplements included sleep and anxiety medication, magnesium, and melatonin. Incarcerated persons had no access to screens from 9 to 11 pm, which may have affected their response.

Quantitative analysis

Yoga Nidra and affect

Of the 33 focus group participants, 30 had pre- and post-Yoga Nidra PANAS scores available for analysis. Mean PA scores decreased 13%, from 28.0 ± 7.0 at baseline to 24.5 ± 9.4 after Yoga Nidra (p = 0.06; Fig. 3). Mean NA scores decreased 31%, from 18.1 ± 7.4 at baseline to 12.5 ± 4.3 after Yoga Nidra (p < 0.0001).

FIG. 3.

Positive and negative affect before and after Yoga Nidra. Mean PANAS scores were calculated for all participants (N = 33). Possible PANAS subscale scores range from 10 to 50. The asterisk indicates statistical significance (p < 0.0001). PANAS, positive and negative affect schedule.

Sleep poll

According to a poll taken immediately after the Yoga Nidra practice, 30% of participants (n = 10) believed they slept during the practice.

Qualitative analysis

Three primary themes were identified from the focus group discussions: participants' responses to Yoga Nidra, factors affecting participants' engagement with the practice, and the potential for Yoga Nidra as a clinical intervention. Subthemes and participant quotes that support primary themes are presented here; each quote is followed by the focus group number and participant ID.

Theme 1: Response to Yoga Nidra

The first theme that was identified outlined participants' physiological, emotional, and mental responses to Yoga Nidra and included the subthemes of relaxation, sleep, and “sense withdrawal” (pratyahara).

Relaxation

Across all focus groups, participants outlined how they felt during and after the practice in terms of emotional, mental, and physical states. In many cases, heightened emotions, racing minds, and physical tensions subsided as the practice progressed.

Noting mental and emotional change, a participant said, “It can take me an awful long time to get settled on my own, and chasing thoughts and that sort of a thing, and I found after about 5 minutes of being irritated… I settled into having an empty brain very quickly which is not usual for me” (FG1, P7).

Describing the physical response, another said, “I felt like it was, again, just very relaxing and I was noticing some pain in my body that he was kind of just talking to me but I was still able to kind of just relax into the meditation and almost fall asleep” (FG5, P3).

Sleep

Three components of sleep were identified: its production during the practice, the mechanism of its production, and the awareness maintained throughout various sleep stages. Quotes pertaining to sleep and its subthemes are given in Table 2.

Table 2.

Participant Quotes Indicating the Experience of Sleep or Sleep-Like States

Sleep subtheme	Quote	Comments
Production of multiple sleep stages	“I am blown out of the water that I actually fell asleep…I fancy myself like this horrible sleeper…but I think I actually woke myself up snoring. Like, I really fell asleep” (FG4, P5)	Sleep indicated by snoring
	“I think that I was fading out a little bit and then I'd come to and then fade and then come to” (FG3, P1)	Light sleep (N1/the first sleep stage) indicated by entering it repeatedly
	“I don't think I completely fell asleep, but I felt like in a—like it was hard to move so it was some deeper state” (FG5, P3)	Deep (N3), REM sleep, or pratyahara, indicated as feeling of paralysis or disconnect from the body
	“Do you remember the spaceship?” (FG1, P5)	REM sleep as indicated by images that were not listed in the script
	“There's some real power in being able to go to sleep and then be able to come back and feel rested. There was a few times where I'd gone to sleep in my apartment and I just can't get up, my body is so tired. With Yoga Nidra, it seems because they have that pattern of going down and back up, you know, I'm confident I can take 20 or 30 minutes and then be ready to function” (FG4, P1)	Restorative beneficial rest indicated by waking up not feeling drowsy
Mechanism of sleep production	“I remember the body parts and that's all” (FG1, P12)	Sleep may be produced after rotation of consciousness (listing of body parts)
	“One of the things I say about Yoga Nidra here, is like ‘I will not sleep’ and that was usually right around the time I fall asleep, and then right after I do. Say ‘you will not sleep’, then you do.” (FG1, P9)	Intention not to sleep may cause sleep
	“it seems like a story, but the order was off” (FG1, P1)	Visualizations may produce dreaming by drawing on memory and emotion (as indicated by creation of a story from listed visuals)
Awareness during sleep	“I felt asleep but still awake because I was listening to what he was saying and I did hear a little bit of the background noise but I also just felt totally asleep.” (FG3, P1) “I feel like I remember pretty much everything. There was a river, and a deep forest, and waves and a beach and a dock and a boat and a dark night and a starry night…” (FG1, P7) “I remember the visualizations, but my experience of the visualization was interesting in that, at first it was the flowing river, then the boat then the sandy banks and the dock and here I am like, continuing the story in my mind…” (FG1, P1) “I don't remember exactly every cue, but I know that I would kind of flash through different locations and like memories of certain places that I've been to.” “Kind of like a dream” (interviewer) “Yea” (FG2, P1)	Awareness of surroundings and audio cues while feeling asleep. Recollection of listed visuals. Recollection of visuals with possible integration into dreaming. Remembering experiences of dreaming while also being aware of visuals listed to them during the practice
	“[I] felt very just like introspective and kind of in touch with the emotions and the memories that were coming up during the practice” (FG2, P2)	Conscious processing of memories and emotions (self-learning) during “alert” dreaming
	“Because I was able to view [my] stressful situation from outside my body I felt more determined to be able to go ahead and do the task” (FG2, P2)	Possible self-learning related to new perspectives and increased drive

Rapid Eye Movement sleep (REM); associated with dreaming.

Pratyahara

Across the focus groups, participants described the “sense withdrawal” traditionally associated with Yoga Nidra, including loss of body boundaries and entering a trance-like state.

One person said, “I kind of lost a sense of the, like, boundaries of my body, so I was aware that I was present, but I kind of stopped feeling such as where my feet touch the floor, or where my hands touch my legs, that kind of thing” (FG1, P7).

Theme 2: Factors affecting engagement

The second theme that was identified outlined factors that affected participants' engagement with Yoga Nidra and included the subthemes of the delivery of the practice and intrapersonal factors.

Delivery of the Yoga Nidra practice

A common subtheme occurring across focus groups, and one relevant to understanding the feasibility of Yoga Nidra as an effective intervention, outlined issues with the delivery of the practice, specifically as it related to the quality of the recording, the voice on the recording, the script itself, and additional asana practice before Yoga Nidra.

Quality of recording and the voice

The Yoga Nidra practice used in this study was a traditional Yoga Nidra script written and recorded by Satyananda Saraswati. Some participants felt distracted by the voice (accent, gender, and inflections) or sound of the recording (feeling it was old or of poor quality).

Yoga Nidra script

Participants made few comments on the script itself, and most of these commonly noted use of Sanskrit and visuals they could not identify with as factors that affected their ability to engage with the practice.

Asana practice before Yoga Nidra

Finally, participants sometimes had expectations about how to better prepare for a Yoga Nidra practice, such as completing more than one asana before lying down.

For example, “For me it was a little bit sudden to walk and lay down…I could've used another movement, so I could've been settled into the mat” (FG1, P1).

Practice environment

Finally, a smaller group of participants from the focus groups noted their attention to environmental factors that were outside of the recording or themselves. In general, these had to do with sounds and other people in the room, the temperature of the space, and the amount of light as detracting from the overall experience.

For example, “In the beginning, the outside noise, from the cars driving by and all that, was something that was challenging for me to try to get past, way more than before. That was annoying” (FG1, P12).

Intrapersonal factors

Across all focus groups, participants were conscious of intrapersonal psychosomatic factors that impacted their ability to engage with the practice, including the mind, the body, and their own experience with mind–body practices in the past.

Mind

For some participants, their interrupting thoughts were the most important barrier to engagement.

For example, a participant said, “I had a little bit of a hard time kind of settling into the practice I think I had a busy brain heading into it” (FG1, P1). Another similarly said, “I'm ADHD and I'm super jittery, I can't help it” (FG6, P3).

Body

For other participants, they felt held back by bodily discomfort (lying on the floor), pain, tension, restlessness (from caffeine), and other physical diagnoses (e.g., fibromyalgia).

One participant noted involuntary deep breathing amid physical distraction: “I'm actually just not feeling very well in general today, along with pain and inflammation, so it was difficult to get past that, so I am not sure I really appreciated it very much. I did take a few insanely long breaths” (FG1, P4).

Experience with mind–body practices

Finally, participants described how their own prior experience with Yoga Nidra or other mind–body practices may have impacted their perception of the Yoga Nidra practice.

One participant, a yoga teacher, expressed distraction from ongoing mental comparisons with her own teaching style.

For others, their lack of prior experience created their expectations about the practice. One participant pointed out possible benefits of frequent Yoga Nidra practice before therapeutic results could be achieved, saying, “This was my first time doing Yoga Nidra and I've done yoga before but this is a different type of yoga so I didn't know what to expect. So, the second time around, knowing what to expect I'd feel less anxious in a way…I feel like it would be easier to get to that relaxed state… just from having that experience of doing it the one time” (FG2, P2).

Theme 3: Potential as a clinical intervention

The third theme to come out of the focus group discussions applied to the potential to use Yoga Nidra as a clinical intervention for common conditions, including insomnia, anxiety, and pain.

Insomnia

Across the focus groups, participants were overwhelmingly positive about future use of the practice for themselves and loved ones: in the case of insomnia, for both perceived benefits, and because they felt capable of reproducing the practice at home.

One participant stated, “I have problems with insomnia, and I think that it would help me a lot” (FG1, P12), while another said, “I need a serious copy of that thing” (FG5, P5).

In speaking of how their chronic illness impacted sleep, one participant said, “Fibromyalgia is the diagnosis, but I have a brain disease that has caused a lot of involuntary muscle spasming throughout my whole life and so it's—I find it difficult to relax the muscles. I invite them to and ask them to, they get all tightened up and hurt. Sleep is crucial, and I think Yoga Nidra is really going to help me” (FG5, P2).

Some participants also discussed potential challenges of a home practice, including bed partners, how to shut off the recording, and the alternative option of practicing midday.

Anxiety

Participants volunteered strong statements to support the potential therapeutic value of Yoga Nidra for anxiety.

One participant noted change in anxiety as well as physical symptoms that accompany it, saying, “I felt less anxiety or anxiousness. I have a little bit of a headache and stomachache that has kind of gone away” (FG5, P6).

Pain

Decreased pain or distraction by pain was also reported in response to Yoga Nidra. One participant made the powerful statement, “At first didn't feel I could get into it because of my back injury and hardware in my spine. My legs and arms are restless, but this was the first time, I was able to lay here, and didn't feel any of that. I wish I could have something similar in the room at night…. It's great right now. These guys will tell you. I haven't been able to move for days. That made a big difference, a big difference. Thank you” (FG6, P5).

Limitations

There were three major limitations of this study, largely highlighting directions in which the authors could expand for future research. First, no objective physiological measures were used here. Such physiological measurements would allow further understanding of how the practice of Yoga Nidra may affect the physical body and brain, separate from cognitive experience, and contribute to understanding changes to consciousness produced by Yoga Nidra. Another limitation is that this study assessed participant response to just one session of Yoga Nidra. While there were many types of experiences and benefits reported from a single practice, repeated sessions may lead to lower prepractice anxiety about Yoga Nidra, deeper experiences,³³ and a better understanding of the use of Yoga Nidra as a clinical intervention. Lastly, although this study focused on the effects of Yoga Nidra when practiced in a group setting, Yoga Nidra may also be practiced independently at home. Practicing Yoga Nidra at home may be more convenient to access, may provide more control over the environment, and offers the possibility of less social distraction. Therefore, practicing Yoga Nidra at home may help address some of the barriers to engagement found in the group practice environment—an observation that deserves future study.

Discussion

The purpose of this study was to investigate participant experiences of Yoga Nidra as a relaxation practice, to evaluate the potential for investigating it further in clinical trials, as a potential treatment for insomnia. The results indicate that participants experienced expected outcomes such as relaxation, sleep, and positive overall experiences with the practice. Although there were occasional minor and easily addressed challenges of engaging with Yoga Nidra, this practice appears to represent a useful and accessible intervention for various clinically relevant biopsychosocial issues (such as sleep, anxiety, and pain), warranting additional research.

The results of this study add to existing evidence supporting the effects of Yoga Nidra on sleep, pain, and stress, as well as its acceptability and credibility as a potential intervention for sleep.^17,19,23 The results align with previous work describing decreased average PA and NA immediately after a similar length of meditation,³⁶ producing a “zen”-like state that may facilitate sleep. The results also align with published descriptions of the state of Yoga Nidra produced by seasoned practitioners²⁷ and they extend upon the literature by giving voice to the experiences of novice practitioners of Yoga Nidra whose responses suggest that even a single practice can produce deep relaxation, sleep, and a unique state of awareness. Accounts of maintained awareness throughout sleep; pratyahara/sense withdrawal; self-reported mental, physical, and emotional relaxation; and sleep (by nearly one-third of the sample) align well with traditional descriptions of Yoga Nidra.^12,34 Helping to validate the intervention (i.e., the selected Yoga Nidra recording and its delivery to participants), participant experiences in this study agree with previous studies that describe accounts of the state of Yoga Nidra, experienced as cognitive awareness during physiological sleep,^27,34 withdrawal of senses to decrease pain and discomfort,¹⁷ and decreased executive attention during Yoga Nidra.³³ The participants' experiences also support previous reports of enhanced relaxation³⁵ and perceived improvement of sleep.^19,25

This study had several strengths. Both qualitative and quantitative methods of data collection were used as a means of triangulating participants' experiences as a foundation for building future interventions. By grounding the focus group discussions in participants' experience, a better understanding was gained about what participants enjoyed and what they perceived as barriers to engagement. In addition, many of the participants were novice practitioners of Yoga Nidra, allowing the authors to capture first impressions of this practice that may be relevant to individuals seeking to try Yoga Nidra for insomnia. The authors also learned about what participants recalled from a single practice of Yoga Nidra, contributing to the literature on the unique state of awareness during sleep potentially created by this practice.

To address challenges voiced by some participants regarding recording quality, accent, and gender/character of the voice, subsequent studies of Yoga Nidra³⁶ have used a recording made by a native English speaker, using modern recording technology, a female voice, and largely excluding use of Sanskrit words, for the sake of comprehension by yoga-naive practitioners. No complaints have been noted since making this change. Ideally, scripts could be offered using various voices, languages, and styles, creating choices for practitioners.

Conclusion

This study supports the feasibility and perceived efficacy of Yoga Nidra as a relaxation practice that may have potential applications for improving sleep. Many participants found the practice to be restful; comfortable; and beneficial mentally, physically, and emotionally. The authors found a Yoga Nidra practice, delivered as an audio recording in a group setting, to be acceptable and tolerable among community-dwelling and incarcerated adults. The results suggest that Yoga Nidra may be worthy of further investigation as a clinical intervention for sleep, anxiety, pain, and a variety of other psychosocial issues. Insomnia is a complex condition that is interrelated with other chronic disease states, including anxiety and pain.^37–39 The multidimensionality of sleep disorders makes Yoga Nidra an appealing therapy for further investigation as a mind–body intervention that holistically targets many aspects of health at once.

Author Disclosure Statement

The authors report no known conflicts of interest with this study.

Funding Information

This study was funded by the grant 5R90AT00892403 from the National Center for Complementary and Integrative Health of the National Institutes of Health, United States.

Supplementary Material

Supplementary Data S1

Supplementary Data S2