Visual representations of single- and multi-sport participation in a youth swimming sample: Implications for definitions and discussions of early specialization.

Academic literature and sport policy documents have cited concerns about an increasing prevalence of early sport specialization, with associated burnout, dropout, and injury. However, evidence to support such statements is limited. Definitions of early specialization vary, but a common criterion is continued participation in a single sport, prior to adolescence. We explored the prevalence of single-sport participation and other patterns of sport involvement from ages 6-12 in a Canadian swimming sample using retrospective longitudinal methods. Parents of 236 competitive swimmers (ages 12-17) completed surveys on their children's sport backgrounds, including the number of sports participated in annually from age 6-12. A cluster heat map elucidated single- and multi-sport patterns over time. Mixed analyses of variance tested for differences by gender and club type. Fourteen percent of our sample showed stable participation in either one sport or multiple sports per year over time, 25% decreased their annual number of sports, and 60% increased. This trend of increasing, rather than decreasing the number of sports in their annual activity roster when approaching age 12 was particularly pronounced for girls. Only 10 participants (4% of the sample) consistently engaged in a single sport each year from age 6-12. Summer (seasonal) swimmers consistently did more sports than year-round swimmers. Overall, our findings showed highly idiosyncratic longitudinal patterns of sport participation that did not easily conform to current sport activity guidelines. We also found similar idiosyncrasy in an ad-hoc analysis of participants who had dropped out of swimming a year later. If single-sport participation is considered a key criterion for defining early specialization, our findings suggest the prevailing narrative around early specialization may be overstated in relation to the number of single-sport athletes. Alternatively, other components of early specialization may be more prevalent and deserving of attention due to possible associations with harmful outcomes.