The complexities of athlete development in North American professional sport.

As the number of roles and positions within professional sport organizations dedicated to athlete development grows, coaches and other interest-holders continue to look to empirical evidence to guide their approaches and inform decision-making. Unfortunately, evidence to date is limited, leaving practitioners wondering how they can best support and make positive change in the athletes under their care, especially when these athletes are typically adults and at the most elite stages of their sporting careers. Using a narrative review approach, this work draws from areas within sport science including talent development, research methods, and athlete support to highlight some of the contemporary issues faced by practitioners in these roles. The main challenges identified include (a) definitional ambiguity, (b) measurement and analysis challenges, (c) restrictive theoretical modeling, and (d) implementation science barriers. Overall, based on the limited, high-quality, empirical evidence to date, decisions on what is "best" for professional athletes at this stage of their careers remains elusive. Caution should be taken when making assumptions, and applying a "one size fits all approach" for athlete development in early adulthood.