{
  "abstract": "Objective To examine nonlinear associations and reference thresholds between physical fitness performance and refractive outcomes in children and adolescents. Methods We surveyed 17235 students aged 6-18 years from 35 schools in seven counties or cities in Hainan Province in December 2023. Cycloplegic autorefraction was used, and spherical equivalent refraction averaged between the two eyes (SEmean) of [≤]-0.50 diopters was classified as myopia. Models adjusted for age, sex, ethnicity, urban-rural residence, near-work duration, outdoor activity time, parental myopia history, BMI, and a centered BMI-squared term, with school-clustered robust standard errors. Waist-to-height ratio was examined in sensitivity analyses. Results The overall myopia prevalence was 64.43%. Among students aged 6-12 years, rope skipping showed a nonlinear association with refractive outcomes, with a reference threshold of 66 skips/min. Below this threshold, each additional 10 skips/min was associated with lower odds of myopia (OR 0.949, 95% CI 0.919-0.980; P=0.001) and a 0.034-D shift toward more hyperopic SEmean (95% CI 0.016- 0.052; P<0.001). Among students aged 16-18 years, endurance performance showed no clear overall nonlinearity; however, beyond 307 s, each additional 10 s was associated with higher odds of myopia (OR 1.255, 95% CI 1.030-1.531; P=0.025) and a 0.098-D shift toward myopia in SEmean (95% CI -0.171 to -0.026; P=0.007). Sensitivity estimates were directionally consistent. Conclusions Fitness indicators showed range-specific associations with refractive outcomes. The two thresholds should be regarded as exploratory values for school-level risk stratification rather than causal or diagnostic cutoffs. Missing direct body-composition measures and the cross-sectional design limit interpretation of independent effects.",
  "abstract_shown": true,
  "affiliations": [
    "Hunan University of Technology"
  ],
  "article_type": "PUBLISHAHEADOFPRINT",
  "arxiv": null,
  "author_total": 3,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "A. Li"
    },
    {
      "name": "L. Xin"
    },
    {
      "name": "J. Zhou"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/fgvasvfdp1ggg.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.10.20.26365985",
  "fulltext_url": "https://www.medrxiv.org/content/10.64898/2026.10.20.26365985v1.full",
  "id": "fgvasvfdp1ggg",
  "issns": [],
  "landing_url": "https://www.medrxiv.org/content/10.64898/2026.10.20.26365985v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "medrxiv",
      "sports medicine"
    ],
    [
      "openalex",
      "2713|Ophthalmology and Visual Impairment Studies"
    ]
  ],
  "openalex": "W7223219403",
  "pdf_url": "https://www.medrxiv.org/content/10.64898/2026.10.20.26365985v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-20",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/fgvasvfdp1ggg.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:21:30Z",
      "native_id": "10.64898/2026.10.20.26365985",
      "source": "medrxiv",
      "url": "https://www.medrxiv.org/content/10.64898/2026.10.20.26365985v1"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2713|Ophthalmology and Visual Impairment Studies",
      "subfield": "epidemiology-public-health"
    }
  ],
  "title": "Associations of rope-skipping and endurance running performance with myopia and spherical equivalent refraction in children and adolescents: a cross-sectional study",
  "title_text": "Associations of rope-skipping and endurance running performance with myopia and spherical equivalent refraction in children and adolescents: a cross-sectional study",
  "type": "preprint",
  "updated_at": "2026-10-30T12:21:30Z",
  "url": "https://research.draconitic.com/paper/fgvasvfdp1ggg",
  "venue": "medRxiv",
  "versions": []
}