The Hospital Universitari i Politècnic La Fe in Valencia and the Instituto de Investigación Sanitaria La Fe (IIS La Fe) have taken part in a study that validated a more precise way of measuring cardiopulmonary capacity in children and adolescents, according to ABC. The work was carried out in a healthy Spanish paediatric population and published in the Revista Española de Cardiología. The regional health ministry announced the findings in a statement.
Why it matters
Exercise tests that measure how the heart, lungs and muscles respond to physical effort are already used in paediatrics. They help doctors investigate symptoms that appear during exercise, monitor children with heart or lung disease, and shape physical activity and rehabilitation programmes. The weak point has been interpretation. Until now, clinicians have largely relied on equations that factor in weight or height, methods in use since the 1980s. Those equations do not always capture what happens as a child grows, particularly in those who are underweight, overweight or obese.
How the Z-score approach works
The validated model is built on a statistical tool known as the Z-score. It compares an individual child's result with the values expected in children of similar characteristics. According to ABC, this reduces the sway body weight holds over how results are read, giving a less biased assessment of cardiopulmonary capacity, especially in children and adolescents who are overweight. The researchers report that the approach produces more accurate and consistent results than the traditional equations.
The study drew on more than a thousand healthy participants under 18. It used Spanish data to validate a model that had been developed from a previously published international reference population. Three Spanish hospitals took part: La Fe in Valencia, the Hospital Universitario Donostia and the Hospital Universitario Virgen del Rocío in Seville, the regional government said in a statement.
One of the main indicators in these assessments is peak oxygen consumption, which shows how well the body uses oxygen during intense physical effort.
Better identification and follow-up
According to ABC, validating the model could help clinicians spot children with low aerobic capacity more reliably. Low aerobic capacity is a factor linked to cardiovascular and metabolic health. The tool may also support the monitoring of paediatric patients with chronic conditions, allow exercise intensity to be matched to their needs, and help teams assess how patients respond to rehabilitation programmes or lifestyle interventions.
Esteban Peiró, a paediatric cardiologist and researcher at La Fe and IIS La Fe, framed the aim in practical terms. He said the goal is not simply to obtain a number but to understand better what that number means for each child or adolescent.
The study concludes that the Z-score model gives a more precise and consistent reading of paediatric cardiopulmonary capacity than traditional methods, and that its use could improve clinical assessment, patient follow-up and the evaluation of interventions intended to raise fitness levels.
The research sits within Qualirehab, a European project running a hybrid cardiac rehabilitation programme for children and adolescents with chronic diseases. The consortium brings together reference centres in France, Germany, the United States and Spain. It received funding from the Consejo Superior de Deportes and from the European "Innovate to Prevent" call. The study is registered on ClinicalTrials.gov.
What to watch is whether the model moves from a validated research tool into routine use in paediatric exercise laboratories, and how quickly clinics adopt it in place of the older weight- and height-based equations.
