How High Can a Child Jump? Spanish Study Sets New Benchmarks for Youth Fitness

Every physical education teacher, youth sports coach, and pediatrician eventually faces the same deceptively simple question: is this child’s jump height normal for their age? A new study published in BMC Pediatrics by researchers from the Universidad de Castilla-La Mancha, Universidad Loyola Andalucía, and Universidad Europea de Madrid now offers one of the most comprehensive answers to date for young athletes. Drawing on data from 3,525 Spanish children and adolescents aged 6 to 17 who participate in extracurricular sports, the team led by Laura Moreno-Gonzalez and Samuel Manzano-Carrasco has produced updated normative reference values for the vertical jump test, one of the most widely used field-based measures of lower-body muscular strength in youth. The work fills a significant gap, because although the vertical jump has long been validated as a reliable indicator of neuromuscular fitness, reference values for sport-participating Spanish youth were outdated or absent, leaving practitioners to compare children against benchmarks that no longer reflected the population they serve.

The vertical jump test occupies a special place in exercise science because it distills a remarkable amount of physiology into a single number measured in centimeters. When a child performs a countermovement jump, dipping down and then explosively extending the hips, knees, and ankles, the height achieved reflects the coordinated output of muscle cross-sectional area, fast-twitch fiber recruitment, tendon stiffness, intermuscular coordination, and the nervous system’s ability to trigger all of these in a fraction of a second. In this study, participants performed the countermovement jump with a free arm swing, a version of the test that mirrors natural athletic movement and allows young jumpers to use their arms for momentum, as they would on a playground or a sports field. Because the test requires nothing more than a wall, a chalk mark, or a simple jump meter, it can be administered cheaply and quickly to hundreds of children, which is precisely what makes robust reference values so valuable.

To transform raw jump heights into meaningful benchmarks, the researchers employed a sophisticated statistical framework known as Generalized Additive Models for Location, Scale, and Shape, or GAMLSS. Unlike classical methods that assume measurements follow a simple bell-shaped curve at every age, GAMLSS allows all the parameters of the distribution to change smoothly as children grow. The location parameter captures the center of the distribution, the scale parameter describes how spread out jump heights are, and the shape parameter accounts for skewness, the tendency of a distribution to lean toward high or low values. The team used families of distributions built on Box-Cox transformations, including the Box-Cox Cole and Green, Box-Cox Power Exponential, and Box-Cox t distributions, fitting them with penalized B-splines, flexible curves that can bend to follow the true developmental trajectory without overfitting the data. The result is a set of smoothed percentile curves that describe, for any given age and sex, exactly where a child’s jump performance falls relative to peers.

The findings confirm and quantify what coaches observe on the field every day. Vertical jump performance increased steadily with age in both boys and girls, reflecting the natural growth of muscle mass, stature, and neuromuscular maturation throughout childhood and adolescence. Boys generally recorded higher jump values than girls across the age range, but the most striking pattern emerged after the age of 12 to 13, when the gap between the sexes widened considerably, particularly at the upper percentiles of performance. This timing aligns closely with the onset of puberty, when rising testosterone levels in boys drive disproportionate gains in lean muscle mass and explosive power, while girls’ trajectories continue to improve but at a more gradual rate. The fact that the divergence was most pronounced among the highest performers suggests that elite-level athletic potential in jumping tasks separates sharply along sex lines once pubertal hormones enter the picture, a phenomenon rooted in well-documented sexual dimorphism in body composition and muscle physiology.

What makes this dataset particularly useful is that it focuses specifically on sport-participating youth rather than the general school population. Children and adolescents enrolled in extracurricular sports represent a distinct reference group: they are typically more active, better conditioned, and more accustomed to explosive movements than sedentary peers. Using general-population norms to evaluate a young footballer or basketball player would systematically underestimate what a trained child should be able to achieve, potentially flagging healthy athletes as underperforming or masking genuine weaknesses behind inflated expectations. By establishing percentiles within the sporting population itself, the study gives coaches and sports scientists a fairer yardstick. A 10-year-old girl at the 25th percentile of the sport-participating distribution can now be identified and supported before a strength deficit compounds into poor technique, injury risk, or dropout from physical activity altogether.

The practical applications extend well beyond talent identification. Low levels of muscular fitness in childhood are consistently associated with adverse health outcomes later in life, including cardiometabolic risk factors, poor bone health, and reduced physical function. Surveillance programs that track youth fitness over time depend on reference values to translate raw measurements into interpretable percentiles, and the authors emphasize that their tables allow practitioners to describe the relative position of any child within the reference population. A pediatrician monitoring an adolescent recovering from injury, for example, can use the age- and sex-specific curves to set realistic rehabilitation targets and track progress against peers rather than against professional adult athletes. School-based fitness assessment programs, which in Spain and across Europe have grown in scale and policy importance, gain a validated, current reference standard that can be applied immediately without expensive laboratory equipment.

Behind the clean percentile curves lies a substantial logistical and ethical undertaking. The data were collected as part of the Active Health project, approved by the Bioethics Committee for Clinical Research of the Virgen de la Salud Hospital in Toledo, with written informed consent obtained from the parents or legal guardians of every participant before any testing took place. Children and their families were informed about the objectives and characteristics of the tests, and participation was voluntary. The scale of the sample, more than three and a half thousand young people spanning eleven years of age, is what gives the GAMLSS curves their stability, particularly at the extreme percentiles where small samples typically produce erratic estimates. The study received funding support from the Spanish Ministry of Science, Innovation, and Universities, the Spanish state research agency, the European Union’s NextGenerationEU program, and the Universidad de Castilla-La Mancha, reflecting the institutional investment that large-scale pediatric fitness research requires.

The study also carries a methodological lesson for the field. Reference values are not timeless constants; they are snapshots of a population at a particular moment, shaped by changing patterns of physical activity, body composition, and sports participation. As childhood lifestyles shift, with screen time rising and habitual movement declining in many countries, yesterday’s norms can quietly become misleading, either flattering a declining population or unfairly penalizing a improving one. By publishing updated, openly accessible reference values for a large and well-characterized sample, the Spanish team has given the international community both a practical tool and a template: other countries and regions can replicate the approach, using the same countermovement jump protocol and the same GAMLSS machinery, to build comparable benchmarks that allow cross-national surveillance of youth muscular fitness for the first time in a truly standardized way.

For parents watching a child leap for a basketball rim or sprint across a football pitch, the science behind a single jump is now more transparent than ever. That centimeter mark on the wall encodes the state of a child’s muscles, bones, nervous system, and hormonal development, all filtered through the context of age and sex. With these new normative values, a jump is no longer just a number on a record sheet; it becomes a calibrated signal, telling coaches, clinicians, and researchers whether a growing body is tracking along a healthy developmental path or quietly falling behind. In an era when childhood physical inactivity is recognized as a global public health concern, tools that make strength visible, measurable, and interpretable at scale may prove to be among the simplest and most powerful instruments in preventive medicine, and this study has handed that instrument to anyone with a wall, a measuring tape, and a child willing to jump.

Subject of Research: Normative reference values for vertical jump performance as an indicator of lower-body muscular strength in sport-participating children and adolescents in Spain

Article Title: Normative reference values for the vertical jump test in sport-participating children and adolescents in spain

Article References: Moreno-Gonzalez, L., Manzano-Carrasco, S., Felipe, J. L., Gallardo, L., Garcia-Unanue, J., & Alonso-Callejo, A. (2026). Normative reference values for the vertical jump test in sport-participating children and adolescents in spain. BMC Pediatrics. https://doi.org/10.1186/s12887-026-07796-1

Image Credits: AI Generated

DOI: 10.1186/s12887-026-07796-1

Keywords: vertical jump test, countermovement jump, normative reference values, physical fitness, lower-body muscular strength, children and adolescents, percentiles, GAMLSS, pediatric health, youth sports, sexual dimorphism, Spain