# Relative age of youth swimmers and their sporting performance at the end of the season

**Authors:** Mendoza-Castejón D, Trinidad A, De la Calle L.M, Belando-Pedreño N, Mohamed Said, Mohamed Said, Mohamed Said, Mohamed Said

PMC · DOI: 10.1371/journal.pone.0335041 · PLOS One · 2025-10-28

## TL;DR

This study examines how the relative age of young swimmers affects their performance, finding that it is influenced by factors like training and body weight.

## Contribution

The study reveals that relative age effects on performance are mediated by contextual and individual factors in youth swimmers.

## Key findings

- Relative age had no direct effect on athletic or academic performance.
- Significant differences were found based on birth quartile, month of birth, and training frequency.
- BMI and sport category mediated the relationship between relative age and performance.

## Abstract

This study explores the influence of relative age on the athletic and academic performance of young swimmers, while also considering other contributing factors such as training conditions, anthropometric characteristics, and coaches’ subjective evaluations. A descriptive, explanatory, and prospective design was employed, using quantitative (questionnaires) and observational methods. The sample consisted of 33 national-level swimmers (11 males and 22 females). Variables analyzed included sex, date of birth, training data, academic performance (AP), final sport performance (SP), coaches’ perceptions of daily performance, and anthropometric measurements. Results indicated no direct effect of relative age on the main variables. However, ANCOVA revealed significant differences based on birth quartile (p = .001), month of birth (p = .001), training frequency (p = .003), and body weight when mediated by sport category. Additionally, significant associations were found between relative age and sport performance when BMI was included as a covariate (p = .036), along with year and month of birth (p = .038; p = .027). Coaches’ perceptions of performance were also significantly related to competitive category (p = .033). It is concluded that while relative age may influence athletic performance, its effect appears to be mediated by contextual and individual factors related to the athlete’s preparation and environment.

## Full-text entities

- **Diseases:** injury (MESH:D014947), disruptive behaviours (MESH:D019958), stroke (MESH:D020521)
- **Chemicals:** oxygen (MESH:D010100), PONE-D-25-21539R2 (-)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Full text

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## Figures

5 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12561930/full.md

## References

63 references — full list in the complete paper: https://tomesphere.com/paper/PMC12561930/full.md

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Source: https://tomesphere.com/paper/PMC12561930