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Deep SleepEvidence & Dosage

N3 slow-wave sleep — physical recovery, GH release.

Studies last updated

Evidence at a glance

Total studies
1,000
With abstract
50
Meta / Systematic / RCT
135
Highly cited
50
Publication years
1962–2026

Deep Sleep in the context of Sleep

This topic is part of our "Sleep" world. There you'll find methodology, evidence and the highest-impact levers — plus the order in which they sensibly build on each other.

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Top studies on Deep Sleep

Ranked by influential-citation count and publication year.

  1. The effects of physical activity on sleep: a meta-analytic review.

    J Behav Med2015meta200 influential citations

    A significant body of research has investigated the effects of physical activity on sleep, yet this research has not been systematically aggregated in over a decade. As a result, the magnitude and moderators of these effects are unclear.…

  2. Systematic review of light exposure impact on human circadian rhythm.

    Chronobiol Int2019n=128systematic173 influential citations

    Light is necessary for life, and artificial light improves visual performance and safety, but there is an increasing concern of the potential health and environmental impacts of light. Findings from a number of studies suggest that…

  3. EEG spectral analysis in insomnia disorder: A systematic review and meta-analysis.

    Sleep Med Rev2021n=977meta167 influential citations

    Insomnia disorder (ID) has become the second-most common mental disorder. Despite burgeoning evidence for increased high-frequency electroencephalography (EEG) activity and cortical hyperarousal in ID, the detailed spectral features of…

  4. Epworth sleepiness scale: A meta-analytic study on the internal consistency.

    Sleep Med2023n=92,503Meta-Analysis167 influential citations

    <h4>Objective/background</h4>The Epworth Sleepiness Scale (ESS) is one of the most used self-reported instruments to assess sleepiness. Thus, several adaptations into different Languages have been performed worldwide over the years. The…

  5. Coffee, caffeine, and sleep: A systematic review of epidemiological studies and randomized controlled trials.

    Sleep Med Rev2017systematic163 influential citations

    Caffeine is the most widely consumed psychoactive substance in the world. It is readily available in coffee and other foods and beverages, and is used to mitigate sleepiness, enhance performance, and treat apnea in premature infants. This…

  6. Interrater reliability of sleep stage scoring: a meta-analysis.

    J Clin Sleep Med2022n=11Meta-Analysis149 influential citations

    <h4>Study objectives</h4>We evaluated the interrater reliabilities of manual polysomnography sleep stage scoring. We included all studies that employed Rechtschaffen and Kales rules or American Academy of Sleep Medicine standards. We…

  7. Sleep in Alzheimer's disease: a systematic review and meta-analysis of polysomnographic findings.

    Transl Psychiatry2022n=28Meta-Analysis145 influential citations

    Polysomnography (PSG) studies of sleep changes in Alzheimer’s disease (AD) have reported but not fully established the relationship between sleep disturbances and AD. To better detail this relationship, we conducted a systematic review and…

  8. Myofunctional Therapy to Treat Obstructive Sleep Apnea: A Systematic Review and Meta-analysis.

    Sleep2015n=120Meta-Analysis140 influential citations

    <h4>Objective</h4>To systematically review the literature for articles evaluating myofunctional therapy (MT) as treatment for obstructive sleep apnea (OSA) in children and adults and to perform a meta-analysis on the polysomnographic,…

    Finding: In adults, myofunctional therapy reduced apnea-hypopnea index from 24.5 ± 14.3/h to 12.3 ± 11.8/h.

  9. Sleep assessment using EEG-based wearables - A systematic review.

    Sleep Med Rev2024n=60Systematic Review131 influential citations

    Polysomnography (PSG) is the reference standard of sleep measurement, but is burdensome for the participant and labor intensive. Affordable electroencephalography (EEG)-based wearables are easy to use and are gaining popularity, yet…

  10. Orofacial Myofunctional Therapy for Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis.

    Laryngoscope2024n=310Meta-Analysis130 influential citations

    <h4>Objective</h4>Orofacial myofunctional therapy (OMT) is an alternative form of treatment of obstructive sleep apnea (OSA), that incorporates various exercises to optimize tongue placement and increase oropharyngeal tone. The objective…

Frequently asked

What dosage was studied?
• Light exposure (specific light exposure; prevailing light conditions at home or work) (Varied across included studies; not specified in abstract) • EEG spectral analysis in insomnia disorder
Which population does the evidence apply to?
Most studies investigated: unknown.
Are there safety considerations for Deep Sleep?
• Not reported in the abstract. • Not reported • Caffeine prolonged sleep latency and reduced total sleep time. • Caffeine reduced sleep efficiency and worsened perceived sleep quality.

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Blackout curtains, sleep mask — melatonin and sleep depth.

Bedroom Temperature

Optimal 17–19°C — a falling core body temperature promotes sleep.

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Sedative/hypnotic — dependence, cognitive risks in older age.

Blue Light Filter

f.lux, Night Shift, glasses — the evidence and the marketing hype.

Bruxism

Teeth grinding — stress, night guard, trigger factors.

Caffeine Timing

Half-life ~5–6h — cut off 8–10h before sleep.

CBD for Sleep

Endocannabinoid system, REM effects, and dosage spectrum.

CBT-I

Cognitive behavioral therapy for insomnia — first-line therapy per the guidelines.

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The internal ~24h clock — light as the main signal, peripheral clocks in the organs.

CPAP

Continuous positive airway pressure — the standard for moderate apnea.

GABA Supplements

Blood-brain barrier, fermented GABA, and efficacy data.

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Deep sleep, lowering body temperature, and 3 g in the evening.

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3g before bed — lowers core body temperature, modulates deep sleep.

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The brain's overnight detox — beta-amyloid clearance.

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