What you've heard: NSDR or yoga nidra can stand in for lost sleep
Can NSDR or yoga nidra replace lost sleep?
A pleasant way to rest, not a substitute for sleep. Evidence grade: Emerging for small benefits.
Published Updated
The "What you've heard" box in Chapter 8
A pleasant way to rest, not a substitute for sleep
The evidence
Guided rest practices such as yoga nidra, and the related practice sold as non-sleep deep rest, do relax people. In the largest online trial the gains in well-being were very small, and a recent review of yoga nidra for insomnia rated the evidence very low certainty.16 Nothing shows that any practice replaces sleep.
Where the book tests it
What the book recommends instead
Make the bedroom dark, cool and quiet, with the phone charging somewhere else
ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.for dark, for sleep timingEmergingEvidence grade: Emerging. Early, small, animal-only, or actively contested.for cool, for the phone in adults, and for heart and metabolic effectsHow: blackout curtains or a blind that works; tape or cover standby lights; let the room cool through the night and adjust the bedding instead of chasing a number on the thermostat; earplugs if noise wakes you. Put a cheap alarm clock by the bed and the phone across the room or outside it. Why: light late in the day pushes the body clock later, and screens in bed go with less sleep.
Related claims
- Is mouth taping safe, and does it work?Unsupported, with a safety catch.Evidence grade: Emerging. Early, small, animal-only, or actively contested.
- Is sunscreen bad for you?Against: the one trial runs the other way.Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.
- Do blue light glasses work for sleep?Mostly unsupported; skip the glasses unless a clinician suggests them for a specific sleep problem.Evidence grade: Strong. Multiple randomized controlled trials, or consistent large cohort studies with a well-understood mechanism.
- Does ten minutes of morning sunlight set your body clock?Right direction, invented number.Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.
- Should you wait 90 minutes after waking for coffee?Untested, and the reasoning looks backward.Evidence grade: Emerging. Early, small, animal-only, or actively contested.
- Do tart cherry juice and magnesium help you sleep?Unproven.Evidence grade: Emerging. Early, small, animal-only, or actively contested.
Sources
The "What you've heard" box in Chapter 8
- 16.Moszeik, E.N., Rohleder, N., and Renner, K.H. (2025). "The effects of an online Yoga Nidra meditation on subjective well-being and diurnal salivary cortisol: a randomised controlled trial." Stress and Health, 41(3), e70049. https://doi.org/10.1002/smi.70049 (Several hundred adults over two months.) ; Singh, S., Dhanlika, D., Singh, U., Haldar, P., and Sharma, G. (2026). "Effect of yoga Nidra (yogic sleep) in sleep disturbances and insomnia: systematic review and metanalysis." Sleep and Breathing, 30(2), 144. https://doi.org/10.1007/s11325-026-03685-0 (Effect sizes d = 0.08 to 0.16.)
Note numbers are those of Chapter 8, Sleep.
This verdict is one of the "What you've heard" boxes in Chapter 8, Sleep, where the book tests the claims people repeat against the studies behind them. The grade rates the evidence behind the verdict, by the book's stated method.
Educational content, not medical advice. Disclaimer.