Biological maturity status and chronological age in young triathletes: a first approach to bio-banding in triathlon

Introduction: The maturation process in young athletes has been widely studied due to its influence on sports performance and training responses. In endurance sports such as triathlon, understanding biological development is crucial for guiding athlete development and competition structuring. Objective: The aim of this study was to investigate the correlation between biological age and chronological age, assess variations in maturity status within age groups, and determine whether bio-banding should be recommended for youth and junior triathlon. Methodology: A cross-sectional study was conducted with 296 young triathletes of both sexes who participated in national, state, or regional multi-sport events in Brazil between 2022 and 2023. Biological maturity status was estimated using the percentage of predicted adult height (%PAH) and predicted age at peak height velocity (APHV). Results: A strong correlation was observed between chronological age and biological age, suggesting that most young triathletes developed within expected standards. Both indicators were considered good estimators of maturity, although the predicted age at peak height velocity appeared to better reflect intra-group variation. The results are consistent with previous studies that support the use of non-invasive maturity indicators in youth sports. The application of these indicators contributes to a more equitable interpretation of performance and training potential across maturity stages. Conclusions: It is concluded that age grouping remains an appropriate method for organizing youth triathlon competitions. However, bio-banding emerges as a strategic alternative for planning training and guiding talent identification, considering biological maturity and its influence on performance.