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  "capturedAt": "2026-11-13T04:11:46.411Z",
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  "work": {
    "type": "RDN",
    "kind": "note",
    "key": "marchant-2025",
    "id": "TAP-RDN-0080",
    "locale": "en",
    "path": "/research/marchant-2025/",
    "title": "TAP reading note: Comparing the Effects of Square, 4–7-8, and 6 Breaths-per-Minute Breathing Conditions on Heart Rate Variability, CO2 Levels, and Mood",
    "description": "Six-breaths-per-minute conditions increased HRV more than square or 4–7–8 breathing during practice. The experiment did not establish a meaningful mood or blood-pressure benefit; mild over-breathing occurred with the six-breath conditions.",
    "rights": "© The Allostasis Project. All rights reserved. Reproduction or adaptation requires separate permission, subject to applicable legal exceptions.",
    "version": "1.0",
    "updatedAt": "2026-11-13",
    "editorial": {
      "contentType": "evidence-review",
      "reviewState": "draft",
      "reviewedAt": null,
      "reviewedVersion": null,
      "updatedAt": "2026-11-13",
      "version": "1.0",
      "byline": "team",
      "author": null,
      "reviewer": null,
      "workflow": {
        "ai": {
          "usage": "used",
          "system": "OpenAI Codex",
          "scope": "Assisted source-based writing and bilingual comparison; consulted materials and unresolved source issues are recorded in the reading notes.",
          "version": "1.0",
          "tasks": [
            "Literature comparison and evidence extraction",
            "Bilingual explanatory writing and source-linked tables"
          ]
        }
      },
      "revisions": []
    },
    "original": {
      "id": "marchant-2025",
      "title": "Comparing the Effects of Square, 4–7-8, and 6 Breaths-per-Minute Breathing Conditions on Heart Rate Variability, CO2 Levels, and Mood",
      "authors": "Joshua Marchant · Inna Khazan · Mikel Cressman · Patrick Steffen",
      "journal": "Applied Psychophysiology and Biofeedback",
      "year": "2025",
      "url": "https://doi.org/10.1007/s10484-025-09688-z",
      "doi": "10.1007/s10484-025-09688-z",
      "pmid": "39864026"
    },
    "references": [
      {
        "id": "marchant-2025",
        "title": "Comparing the Effects of Square, 4–7-8, and 6 Breaths-per-Minute Breathing Conditions on Heart Rate Variability, CO2 Levels, and Mood",
        "authors": "Joshua Marchant · Inna Khazan · Mikel Cressman · Patrick Steffen",
        "journal": "Applied Psychophysiology and Biofeedback",
        "year": "2025",
        "url": "https://doi.org/10.1007/s10484-025-09688-z",
        "doi": "10.1007/s10484-025-09688-z",
        "pmid": "39864026"
      }
    ],
    "sections": [
      {
        "id": "finding",
        "title": "What the study found",
        "paragraphs": [
          "Six-breaths-per-minute conditions increased HRV more than square or 4–7–8 breathing during practice. The experiment did not establish a meaningful mood or blood-pressure benefit; mild over-breathing occurred with the six-breath conditions."
        ]
      },
      {
        "id": "limits",
        "title": "Scope & limitations",
        "paragraphs": [
          "84 university students in a counterbalanced within-person experiment.",
          "One session, a narrow student sample, equipment-related missingness and no longer-term outcomes limit interpretation."
        ]
      },
      {
        "id": "sample",
        "title": "Population & sample",
        "paragraphs": [
          "84 university students in a counterbalanced within-person experiment."
        ]
      },
      {
        "id": "exposure",
        "title": "Exposure or intervention",
        "paragraphs": [
          "Four ten-minute conditions, separated by three-minute rests; last five minutes analysed."
        ]
      },
      {
        "id": "outcomes",
        "title": "Outcomes",
        "paragraphs": [
          "ECG-derived HRV, end-tidal carbon dioxide, blood pressure and mood."
        ]
      },
      {
        "id": "duration",
        "title": "Time frame",
        "paragraphs": [
          "One laboratory session."
        ]
      },
      {
        "id": "funding",
        "title": "Research funding",
        "paragraphs": [
          "Brigham Young University."
        ]
      },
      {
        "id": "conflicts",
        "title": "Research conflicts of interest",
        "paragraphs": [
          "Authors declared no financial or other conflicts of interest."
        ]
      },
      {
        "id": "basis",
        "title": "Reading scope",
        "paragraphs": [
          "Published PDF: protocol, results, limitations and declarations. Supplementary analyses were not reproduced."
        ],
        "links": [
          {
            "label": "Publisher record and supplementary material",
            "url": "https://link.springer.com/article/10.1007/s10484-025-09688-z"
          }
        ]
      }
    ]
  }
}