{
  "abstract": "Objectives: This study examined within-player associations between GPS-derived external training load variables and heart rate-based internal training load during in-season training in elite youth soccer players. A secondary aim was to identify which intensity-based external load variables are independently associated with heart rate (HR) exertion per minute. Methods: Eleven under-17 male soccer players were monitored across a nine-week in-season period. 266 player-session observations were included. External training load was assessed using GPS units with integrated inertial sensors, including total distance covered, high-speed running distance, explosive efforts, player load, and their time-normalized derivatives. Internal training load was quantified using heart rate exertion derived from individualized HR zones. Within-player associations were examined using repeated-measures correlations. A linear mixed-effects model was used to examine predictors of heart rate exertion per minute. Results: HR exertion showed nearly perfect within-player associations with total distance covered (r = 0.921, p < 0.001) and PlayerLoadTM (r = 0.924, p < 0.001), while large associations were observed for high-speed running distance (r = 0.662, p < 0.001) and explosive efforts (r = 0.621, p < 0.001). Intensity-based variables, including total distance covered per minute and explosive efforts per minute, were significant positive predictors of HR exertion·min − ¹. Conclusions: In elite under-17 youth soccer training, cumulative HR exertion primarily reflects accumulated external training volume, whereas HR exertion·min − ¹ is more closely related to locomotor and explosive action intensity. These findings highlight the need to interpret cumulative and intensity-based internal training load metrics separately in within-player training monitoring.",
  "abstract_shown": true,
  "affiliations": [
    "Training Theory and Methodology Research Center, Hungarian University of Sports Science, Budapest, Hungary",
    "Department of Sports Medicine and Digital Health, Faculty of Health and Sports Sciences, University of Győr, Győr, Hungary",
    "Scientific Research Centre of the Hungarian Defence Forces, Transformation Command, Budapest, Hungary"
  ],
  "article_type": "Research Article",
  "arxiv": null,
  "author_total": 3,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Krisztián Havanecz"
    },
    {
      "affs": [
        1
      ],
      "name": "Tímea Téglás"
    },
    {
      "affs": [
        2
      ],
      "name": "Leonidas Petridis"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/cvehra7fv23jd.bib",
  "cited_by": 0,
  "doi": "10.1371/journal.pone.0357176",
  "fulltext_url": null,
  "id": "cvehra7fv23jd",
  "issns": [
    "1932-6203"
  ],
  "landing_url": "https://doi.org/10.1371/journal.pone.0357176",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2732|Sports Performance and Training"
    ],
    [
      "plos",
      "/Biology and life sciences/Physiology/Biological locomotion"
    ],
    [
      "plos",
      "/Biology and life sciences/Physiology/Biological locomotion/Running"
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      "plos",
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      "plos",
      "/Biology and life sciences/Sports science/Sports and exercise medicine/Exercise"
    ],
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      "/Medicine and health sciences/Cardiology/Heart rate"
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      "/Medicine and health sciences/Public and occupational health/Physical activity/Physical fitness/Exercise"
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      "/Medicine and health sciences/Sports and exercise medicine"
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      "/Medicine and health sciences/Sports and exercise medicine/Exercise"
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  "pdf_url": "https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0357176&type=printable",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-11",
  "publisher": "Public Library of Science",
  "ris": "https://research.draconitic.com/paper/cvehra7fv23jd.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:56Z",
      "native_id": "10.1371/journal.pone.0357176",
      "source": "plos",
      "url": "https://doi.org/10.1371/journal.pone.0357176"
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  "subjects": [
    {
      "field": "medicine",
      "origin": "plos:cardiology",
      "subfield": "cardiovascular"
    },
    {
      "field": "medicine",
      "origin": "plos:public and occupational health",
      "subfield": "epidemiology-public-health"
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    {
      "field": "medicine",
      "origin": "plos:physiology",
      "subfield": "physiology"
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  "title": "Within-player associations between GPS-derived external training load and heart rate-based internal training load in elite youth male soccer training",
  "title_text": "Within-player associations between GPS-derived external training load and heart rate-based internal training load in elite youth male soccer training",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:17:56Z",
  "url": "https://research.draconitic.com/paper/cvehra7fv23jd",
  "venue": "PLOS One",
  "versions": []
}