Variable and changing trajectories in athlete development: How relative age and maturation data advocate an inclusive long-term tracking approach


Athlete development not only occurs across a longitudinal period, but it is also often non-linear and variable. For instance, ‘relatively younger - later maturing players’ could hypothetically reduce or negate developmental differences in later adolescence, appearing to show a heightened trajectory of biological and fitness development compared to their ‘relatively older – early maturing’ counterparts. This study applied a methodology to test and assess anthropometric and fitness change in a case samples of rugby league players (i.e., ages 13-15) relative to a broader age and skill matched population (N = 1,172) population across a 2 year period. Findings identified that when using z-scores and radar plot procedures, annual comparisons - versus bi-annual comparisons - generated less deviated z scores across variables, initially suggesting less substantial change in case players in an annual period. However, developmental variability and longitudinal change even within a relatively homogenous sample was still evident and became more clearly evident after two years of tracking. The possibility of ‘later maturing players’ rapidly reducing developmental differences within a two year period was identified. Findings affirm variable development and changing trajectories between adolescent athletes, particular for those of differing maturation status. Practical implications point toward an inclusive long-term inclusive tracking approach as opposed to early (de)selection in athlete development systems associatd with team sport contexts.

Acknowledgments: Authors would like thank the assistance and help of The Rugby Football League (UK) who supported this study.