Methods Used to Reduce the Influence of Biological Maturity on Talent Selection and Development in Youth Team Sports

Background: Chronological age groups in youth sports aim to encourage fair competition. Yet, within chronological age groups, "maturation biases" which favour the selection of relatively early maturing athletes over their peers are often observed. Several strategies that can be used to mitigate this maturity bias have been reported in the literature, yet the studies in which these strategies have been used to alleviate maturational biases have not been systematically identified, evaluated and summarised in order to make the available literature more accessible to researchers and practitioners. Methods: Three electronic databases (i.e. PubMed, SPORTDiscus and Web of Science) were searched for articles that exposed at least one group of team sport athletes aged 10-16y for Males or 8-14y for Females, to an intervention aiming to reduce maturation bias, and included a measure of task performance or athlete selection. The risk of bias and quality of reporting of the two included articles identified as randomised control trials (RCT) were assessed using the Joanna Briggs Institute critical appraisal checklists for RCT's and the Consolidated Standards of Reporting Trials (CONSORT). The nine included articles identified as quasi-experimental were assessed using the JBI critical appraisal checklist for quasi-experimental trials and the Transparent Reporting of Evaluations with Nonrandomized Designs (TREND) statement checklist. Results: The eleven articles included in this review highlight bio-banding and player labelling as the only strategies that have directly addressed the reduction of maturation bias in youth sport. However, the findings of all included articles should be interpreted with caution due to potential risks of bias. Despite all ten articles on bio-banding reporting a number "effects" of bio-banding on performance, there is no direct evidence in the available research to suggest that these also have a meaningful impact on reducing bias during the selection of youth athletes. While less commonly reported on, player labelling was reported to reverse the maturation bias in favour of later maturing youth soccer players, although this study may have observed a fairly homogeneous group of individuals who had not yet commenced a period of increased growth velocity. Conclusions: Although bio-banding and player labelling have been explored as strategies to reduce maturity bias in youth team sports, potential biases identified in the literature underscore the need for further investigation before practical recommendations can be made.