Nap

Daytime sleep. Worth logging separately from night sleep — a long late nap explains a bad night that otherwise looks unprovoked.

Recovery practices

Recovery & healing Nootropics & cognitive

Research records

Historical source snapshot. Not freshly verified, not a recommendation. Study findings, community accounts and app defaults are not interchangeable.

Publication suitability · 2026-10-15: Historical reference only; not a clinical verification. Clinical, regulatory, efficacy, safety and dose claims are not independently established by this review.

Nap

Daytime sleep. Worth logging separately from night sleep — a long late nap explains a bad night that otherwise looks unprovoked.

Evidence category: Systematic review. This describes the source category, not approval or certainty.

Regulatory statement in source: Not separately recorded; do not infer approval from the evidence category.

A nap is a short sleep taken during the day. A meta-analysis of 22 randomised trials in athletes and active adults found better cognitive and physical performance and less fatigue after napping, including after partial sleep loss. A second meta-analysis found improved running measures and less fatigue when naps followed a normal night's sleep. A meta-analysis of 11 studies found a small gain in cognitive performance, mainly alertness. An umbrella review of 16 meta-analyses links long naps with higher risk of coronary heart disease, diabetes and obesity.

Benefits reported in the imported source

Pooled randomised trials found better cognitive and physical performance and less fatigue
Benefits held after partial sleep loss in athletes and active adults

Risks and limits

Muscle force, sprint and Wingate results did not change
In one meta-analysis the cognitive gain was small and mainly about alertness
An umbrella review links long naps with higher coronary heart disease, diabetes and obesity risk

Source bottom line: Short naps consistently improve alertness and performance in trials, while long naps track higher disease risk.

Uncertainty: Reference information only. Not medical advice.

Study protocols — reports, not instructions

291 male athletes and physically active adults aged 18-35 across 22 randomised trials

Reported regimen: A daytime nap between 12:30 and 16:50, most often at 14:00; benefits were larger at 30 to under 60 minutes and over an hour before testing
Duration: Single nap per trial condition
Reported outcome: Cognitive performance rose (SMD 0.69), physical performance rose (SMD 0.99) and perceived fatigue fell (SMD -0.76), also after partial sleep loss.
Source: Is daytime napping an effective strategy to improve sport-related cognitive and physical performance and reduce fatigue? A systematic review and meta-analysis of randomised controlled trials (Mesas et al. 2023)

Claim provenance

evidence.json#/catalog:recovery:nap/protocols/0

Physically active people and athletes in 18 studies, after a normal 7-9 hour night's sleep

Reported regimen: A daytime nap compared with a no-nap condition
Duration: Single nap per trial condition
Reported outcome: Highest and total distance in the 5-m shuttle run improved and fatigue index fell; muscle force did not change (p = 0.267), nor did sprint or Wingate results.
Source: The Impact of Daytime Napping Following Normal Night-Time Sleep on Physical Performance: A Systematic Review, Meta-analysis and Meta-regression (Boukhris et al. 2024)

Claim provenance

evidence.json#/catalog:recovery:nap/protocols/1

16 meta-analyses covering 244 health-related outcomes

Reported regimen: Daytime naps grouped as short (20-30 minutes), under 60 minutes, and over 60 minutes
Duration: Not stated
Reported outcome: Naps under 60 minutes tracked better cognition and less fatigue; naps over 60 minutes tracked 30% higher coronary heart disease and 20% higher diabetes risk.
Source: Multiple Health Outcomes of Daytime Napping: A Comprehensive Umbrella Review (Du et al. 2026)

Claim provenance

evidence.json#/catalog:recovery:nap/protocols/2

381 working-aged adults across 11 studies, almost all in laboratory conditions

Reported regimen: A single daytime nap averaging 55.4 plus or minus 29.4 minutes, mostly in the afternoon
Duration: Single nap
Reported outcome: Cognitive performance improved after the nap (effect size 0.18), mainly alertness (0.29); nap duration and time to testing made no difference.
Source: Effects of a Short Daytime Nap on the Cognitive Performance: A Systematic Review and Meta-Analysis (Dutheil et al. 2021)

Claim provenance

evidence.json#/catalog:recovery:nap/protocols/3

Community and practice descriptions

Accounts of a practice are not evidence of safety or effectiveness. Words such as “standard”, “safe” or “recommended” describe the source account, not verified consensus or this wiki’s advice. Commercial and self-published citations are retained for traceability, not vendor endorsement or independent clinical corroboration.

Unverified imported account — Researchers study how daytime naps may influence health - NHLBI

An imported authored paraphrase, not a quotation or a recommended protocol.

Review: unverified historical account. The imported wording is preserved for attribution; its full clinical, dosing, efficacy or consensus claims have not been independently established. Described practice context only; no clinical benefit or safety outcome is inferred.

Imported wording: An observational report describes midday siestas among adults in Spain, with regular nappers often reporting four days a week.

Researchers study how daytime naps may influence health - NHLBI

Historical research outcome: verified-description · 2026-10-06

The original Sleep Foundation page returned HTTP 403 through both retrieval methods. The replacement describes observed siestas, not a recommended nap duration or an intervention.

https://www.sleepfoundation.org/napping: blocked — Direct retrieval and the web-fetch tool both returned HTTP 403; no claim was retained from this inaccessible page.
https://www.nhlbi.nih.gov/news/2023/researchers-study-how-daytime-naps-may-influence-health: verified-description — The live NIH report explicitly describes observed regular midday siestas in a Spanish adult cohort, often four days a week. Its health-outcome associations are not repeated.

Pharmacokinetic context

No half-life recorded in this source snapshot. No value has been inferred.

Source references

Snapshot provenance

Source ID: catalog:recovery:nap. Commit: adc7684614f9439b41d91a3312b62e7982c7e20e. Review state: historical-not-reverified. Authored links are retained separately from the canonical evidence links in the public data. App templates/defaults and rejected drafts are archived, not deployed.

Related entries and components

None listed.