Validation of a VO₂max Z-score model for fitness assessment in a healthy Spanish pediatric population

Authors

• Esteban Peiró-Molina, Departamento de Cardiología Pediátrica, Hospital Universitari i Politècnic La Fe, Valencia, Spain; Unidad de Medicina Regenerativa y Trasplante Cardíaco, Instituto de Investigación Sanitaria La Fe (IISLAFE), Valencia, Spain.
• Arthur Gavotto, Department de Réanimation Néonatale et Pédiatrique, CHU Montpellier, Montpellier, France; PhyMedExp, CNRS, INSERM, Université de Montpellier, Montpellier, France.
• Julien Robert, Département d'Epidémiologie, Santé Publique et Biostatistiques, CHU de Nimes, Nimes, France.
• Mathieu Andrianoely, IHU Liryc, INSERM U1045, Université de Bordeaux, Pessac, France; Just Coaching, Paris, France.
• Erika Rezola, Instituto de Investigación Sanitaria Biogipuzkoa, Área de Enfermedades Sistémicas, Grupo de Enfermedades Pediátricas, Hospital Universitario Donostia, Servicio de Pediatría, Donostia/San Sebastián, Spain.
• Begoña Manso, Sección de Cardiología Pediátrica, Hospital Universitario Virgen del Rocío, Seville, Spain.
• Francisco-José Ferrer-Sargues, Unidad de Medicina Regenerativa y Trasplante Cardíaco, Instituto de Investigación Sanitaria La Fe (IISLAFE), Valencia, Spain; Departamento de Fisioterapia, Universidad Cardenal Herrera CEU, CEU Universities, Valencia, Spain.
• José Ignacio Carrasco-Moreno, Departamento de Cardiología Pediátrica, Hospital Universitari i Politècnic La Fe, Valencia, Spain.
• Stefan Matecki, PhyMedExp, CNRS, INSERM, Université de Montpellier, Montpellier, France.
• Alfred Hager, Klinik für Kinderkardiologie und Angeborene Herzfehler, Technische Universität München, Deutsches Herzzentrum München, Munich, Germany.
• Naomi Gauthier, Department of Cardiology, Boston Children's Hospital, Harvard Medical School, Boston, United States.
• Suellen Moli Yin, Department of Cardiology, Boston Children's Hospital, Harvard Medical School, Boston, United States.
• Sophie Guillaumont, Service de Cardiologie Pédiatrique, Centre de Compétences M3C, CHU Montpellier, Montpellier, France; Service d'Explorations et Réhabilitation Cardiaque Pédiatrique, Intitut Saint-Pierre, Palavas-Les-Flots, France.
• Thibault Mura, Département d'Epidémiologie, Santé Publique et Biostatistiques, CHU de Nimes, Nimes, France.
• José Miguel Blanco Borreguero, Servicio de Pediatría, Hospital Universitario Virgen de Valme, Seville, Spain.
• Pascal Amedro, IHU Liryc, INSERM U1045, Université de Bordeaux, Pessac, France; Heart and Lung Center, Children's National Hospital, The George Washington University School of Medicine & Health Sciences, Washington DC, United States. Electronic address: [email protected].

Document Type

Journal Article

Publication Date

3-3-2026

Journal

Revista espanola de cardiologia (English ed.)

DOI

10.1016/j.rec.2026.02.006

Keywords

Condición física; Consumo de oxígeno; Exercise test; Oxygen consumption; Pediatrics; Pediatría; Physical fitness; Prueba de esfuerzo cardiopulmonary; Puntuación Z; Reference values; Valores de referencia; Z-scores

Abstract

INTRODUCTION AND OBJECTIVES: Maximal oxygen uptake is the gold standard for assessing aerobic capacity in children and adolescents. Its interpretation requires robust reference models. A pediatric Z-score model has recently been developed, but external validation in independent cohorts is essential to confirm its applicability. METHODS: We conducted a multicenter validation study including a total of 1046 healthy participants (mean age, 12.0 ± 2.6 years), composed of 2 cohorts: a prospective Spanish validation cohort (n = 175) and a previously published reference cohort (n = 871). The Z-score model was compared with historical weight- and height-based linear equations in terms of correlation, prediction error, and classification of impaired aerobic fitness. Subgroup analyses were performed by sex and body mass index. RESULTS: The Z-score model showed the strongest correlation between predicted and observed maximal oxygen uptake (R² = 0.70), outperforming weight-based (R² = 0.64) and height-based (R² = 0.66) equations. It yielded smaller prediction errors among body mass index groups and identified 14% of participants as having impaired aerobic fitness, compared with 20% and 23% using weight- and height-based reference models, respectively. The Z-score model showed improved consistency and reduced bias, particularly in overweight participants. CONCLUSIONS: The pediatric Z-score model demonstrated superior accuracy, consistency, and classification reliability compared with linear equations in a large, independent Spanish cohort. Its adoption may enhance the interpretation of pediatric cardiopulmonary exercise testing, support early identification of reduced aerobic fitness, and guide prevention strategies and tailored interventions. Registered on ClinicalTrials.gov (NCT04876209).

APA Citation

Peiró-Molina, Esteban; Gavotto, Arthur; Robert, Julien; Andrianoely, Mathieu; Rezola, Erika; Manso, Begoña; Ferrer-Sargues, Francisco-José; Ignacio Carrasco-Moreno, José; Matecki, Stefan; Hager, Alfred; Gauthier, Naomi; Yin, Suellen Moli; Guillaumont, Sophie; Mura, Thibault; Miguel Blanco Borreguero, José; and Amedro, Pascal, "Validation of a VO₂max Z-score model for fitness assessment in a healthy Spanish pediatric population" (2026). GW Authored Works. Paper 8939.
https://hsrc.himmelfarb.gwu.edu/gwhpubs/8939

Department

Pediatrics