{
  "abstract": "Background/objectives\n\nFamily circumstances are related to children's physical activity and fitness, yet the two are rarely examined together in the same children. We examined how socioeconomic position and family structure (only-child status) relate to domain-specific reported activity and measured fitness. Socioeconomic position was the mean of maternal and paternal educational attainment, with higher values indicating higher attainment.Methods\n\nWe designed and conducted a cross-sectional survey of 8228 children in grades 1 to 9 from 27 schools. The questionnaire covered the preceding six months in three domains: physical education class, in-school extracurricular activity and out-of-school exercise. Weekly frequency, duration and intensity were reported for each and summed to weekly moderate-to-vigorous activity (MVPA). Fitness comprised 10 device-measured indicators and, in primary grades, a 5-item motor battery. Linear and logistic models used school fixed effects and school-clustered standard errors, with Benjamini-Hochberg correction.Results\n\nMedian reported weekly MVPA was 300 min; 26.3% of the 7533 children with computable MVPA met the 60 min-per-day guideline. Socioeconomic position was associated with reported MVPA (0.077 SD, 95% CI 0.032 to 0.122) and with meeting the guideline (odds ratio 1.21, 95% CI 1.07 to 1.37). The association appeared in out-of-school exercise but not in physical education class, a contrast of 0.064 SD (95% CI 0.024 to 0.104). Socioeconomic position was also associated with lower handgrip strength (-0.044 SD, 95% CI -0.064 to -0.024) and with more sit-ups in primary grades. Only children showed no clear difference in reported activity in any domain, yet they had lower composite fitness (-0.102 SD, 95% CI -0.142 to -0.061), which remained after adjustment for reported MVPA.Conclusions\n\nThe socioeconomic gradient in reported activity was concentrated outside the physical education class; family structure was associated with measured fitness without a matching difference in reported activity.",
  "abstract_shown": true,
  "affiliations": [
    "China Institute of Sport Science, No. 11 Tiyuguan Road, Dongcheng District, Beijing 100061, China.",
    "Graduate School of Health and Sports Science, Juntendo University, Inzai 270-1695, Chiba, Japan.",
    "Weifang Aiyoudong Children and Youth Sports Health Research Institute, Weifang 261061, China."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Yanfeng Zhang"
    },
    {
      "affs": [
        1
      ],
      "name": "Xiang Pan"
    },
    {
      "affs": [
        1
      ],
      "name": "Yibo Gao"
    },
    {
      "affs": [
        2
      ],
      "name": "Haixia Hu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5jmvng9fdg2f4.bib",
  "cited_by": 0,
  "doi": "10.3390/healthcare14193189",
  "fulltext_url": "https://europepmc.org/articles/PMC13665455",
  "id": "5jmvng9fdg2f4",
  "issns": [
    "2227-9032"
  ],
  "landing_url": "https://europepmc.org/article/MED/42881628",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2737|Physical Activity and Health"
    ]
  ],
  "openalex": "W7214632448",
  "pdf_url": "https://europepmc.org/articles/PMC13665455?pdf=render",
  "pmcid": "PMC13665455",
  "pmid": "42881628",
  "published": "2026-09-27",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5jmvng9fdg2f4.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:16Z",
      "native_id": "MED:42881628",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42881628"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2737|Physical Activity and Health",
      "subfield": "physiology"
    }
  ],
  "title": "Two Family Gradients in Children's Physical Activity and Fitness: Socioeconomic Position, Family Structure, and Where They Diverge.",
  "title_text": "Two Family Gradients in Children's Physical Activity and Fitness: Socioeconomic Position, Family Structure, and Where They Diverge.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:19:16Z",
  "url": "https://research.draconitic.com/paper/5jmvng9fdg2f4",
  "venue": "Healthcare (Basel, Switzerland)",
  "versions": []
}