{
  "abstract": "Background: Men display higher absolute fat oxidation rates during exercise than women, but whether fat-free mass (FFM) moderates the substrate-intensity relationship in a sex-specific manner remains untested. Methods: In this cross-sectional laboratory study, we evaluated 37 competitive athletes (20 women, 17 men; age 22 ± 5 years) using dual-energy X-ray absorptiometry (DXA) and indirect calorimetry during incremental treadmill exercise (538 min-by-min observations) to evaluate a sex × FFM × intensity interaction using linear mixed-effects models. Results: The primary sex × FFM × intensity interaction was non-significant (β=+0.014, 95 % CI -0.021 to +0.049; p=0.443). Absolute maximal fat oxidation (MFO) was higher in men (0.826±0.234 vs. 0.655±0.175 g⋅min-1; p=0.038), but it disappeared when normalised to FFM (15.45±4.19 vs. 15.74±4.85 mg⋅kg FFM-1⋅min-1; p=0.847). Interestingly, a strong sex × adiposity (DXA body-fat percentage, %) interaction was identified (β=-0.440, q<0.001), with higher adiposity linked to higher fat oxidation in men (β=+0.339, p<0.001) but lower in women (β=-0.115, p=0.010). Conclusions: Adiposity was identified as the most significant sex-specific moderator, with evidence showing that it is associated with greater fat oxidation in men and lower fat oxidation in women. The male advantage in absolute fat oxidation reflected greater FFM, because MFO per kilogram of FFM did not differ between sexes; muscle oxidative capacity was not measured directly. However, the exploratory nature of the study requires confirmation in future research.",
  "abstract_shown": true,
  "affiliations": [
    "Laboratorio de Evaluación y Cuidado del Estado Nutricio, División de Ciencias de la Salud, Centro Universitario de Tonalá, Universidad de Guadalajara, Tonalá 45425, Jalisco, Mexico.",
    "Red Iberoamericana de Investigadores en Antropometría Aplicada, 04120 Almería, Spain.",
    "Faculty of Education and Humanities, School of Sport Sciences, Universidad Andres Bello, Viña del Mar 2520000, Chile.",
    "Department of Sport Sciences, Faculty of Sport and Health Sciences, Fit Generation Research Institute, AD500 Andorra la Vella, Andorra.",
    "Faculty of Sports Organization, Autonomous University of Nuevo Leon, San Nicolas de los Garza 66455, Nuevo Leon, Mexico.",
    "Department of Physical Activity Sciences, Faculty of Education Sciences, Universidad Católica del Maule, Talca 3480112, Chile.",
    "School of Education, Faculty of Human Sciences, Universidad Bernardo O'Higgins, Santiago 8370993, Chile.",
    "Universidad Autónoma del Paraguay, Asunción 001012, Paraguay.",
    "Vicerrectoría de Investigación y Postgrado, Universidad de Los Lagos, Osorno 5311157, Chile.",
    "Department of Health Research, Icen Cognis, 38370 La Matanza de Acentejo, Spain.",
    "Faculty of Physical Education, National Pedagogical University, Bogotá 480100, Colombia.",
    "School of Medicine, Universidad Espiritu Santo, Samborondón 092301, Ecuador.",
    "Faculty of Health Sciences, Universidad Tecnológica Atlántico Mediterráneo-UTAMED, 29590 Malaga, Spain."
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Carlos Abraham Herrera-Amante",
      "orcid": "0000-0002-3645-3621"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Rodrigo Yáñez-Sepúlveda",
      "orcid": "0000-0002-9311-6576"
    },
    {
      "affs": [
        1,
        4
      ],
      "name": "José Raúl Hoyos-Flores",
      "orcid": "0000-0003-1486-4814"
    },
    {
      "affs": [
        5,
        6
      ],
      "name": "Exal Garcia-Carrillo",
      "orcid": "0000-0001-6190-938X"
    },
    {
      "affs": [
        7
      ],
      "name": "José Adrián Montenegro-Espinosa",
      "orcid": "0009-0004-5387-4083"
    },
    {
      "affs": [
        8,
        9
      ],
      "name": "Fiorella Quiroz-Cárdenas",
      "orcid": "0009-0007-3048-5298"
    },
    {
      "affs": [
        10
      ],
      "name": "Boryi A Becerra-Patiño",
      "orcid": "0000-0002-9581-5071"
    },
    {
      "affs": [
        11,
        12
      ],
      "name": "José Francisco López-Gil",
      "orcid": "0000-0002-7412-7624"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ehmytk1zbgcef.bib",
  "cited_by": 0,
  "doi": "10.3390/sports14100444",
  "fulltext_url": null,
  "id": "ehmytk1zbgcef",
  "issns": [
    "2075-4663"
  ],
  "landing_url": "https://europepmc.org/article/MED/42931582",
  "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",
      "2707|Cardiovascular and exercise physiology"
    ]
  ],
  "openalex": "W7221193309",
  "pdf_url": null,
  "pmcid": null,
  "pmid": "42931582",
  "published": "2026-10-09",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ehmytk1zbgcef.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:22:01Z",
      "native_id": "MED:42931582",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42931582"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2707|Cardiovascular and exercise physiology",
      "subfield": "general"
    }
  ],
  "title": "Sex Differences in Substrate Oxidation During Incremental Exercise: An Exploratory Study on the Role of Body Composition.",
  "title_text": "Sex Differences in Substrate Oxidation During Incremental Exercise: An Exploratory Study on the Role of Body Composition.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:22:01Z",
  "url": "https://research.draconitic.com/paper/ehmytk1zbgcef",
  "venue": "Sports (Basel, Switzerland)",
  "versions": []
}