Impact Of Biological Maturation On Swedish Ice Hockey Players - Implications For Junior And Adult Success

Ice hockey is a physically demanding sport. Hence, players who mature early are more likely to be successful in junior years. This has already been shown in sports such as soccer, and the maturation bias increases at the elite level. However, no previous studies have investigated the effect of maturation and its relationship with junior selection and adult success in ice hockey. PURPOSE: To investigate the relationship between biological maturation and ice hockey success during adolescence and adulthood assessed using selection to junior national teams and the National Hockey League (NHL), respectively. METHODS: Data was obtained from anthropometric records of players from ice hockey schools certified by the Swedish ice hockey association between 1998 and 2017 (n = 4787). Moreover, status of participation in junior national teams, i.e., under-16, -18, -20, and NHL appearances were collected from other sources. Biological maturation was computed as percentage of adult height (%AH), and biological age was calculated by comparison with a Swedish growth reference dataset. Categories of %AH, standard deviation z-scores, and biological age offset describing early, on-time, and late maturation were created. RESULTS: Of 2211 players with maturation data, 217 players had played on the U16 national team (junior success) and 96 reached the NHL (adult success). The difference (95% confidence interval [CI]) in baseline %AH between players with junior vs. adult success was -0.75 (-0.39, -1.11). Looking at age-offset categories in junior success, 30% of players were early maturing and 19% of players were late-maturing, showing a bias towards early maturation (p < 0.01). In contrast, more late-maturing players (40%) achieved adult success than early maturing players (25%), and NHL players displayed significantly later maturation (%AH: -0.48 [-0.80, -0.16]) than non-NHL players. CONCLUSIONS: This unique 20-year analysis shows that junior success in male ice hockey is positively related to early maturation, while adult success is inversely related to advanced maturation. Ice hockey organizations should implement maturation assessments to optimize the development of both late and early maturing players and reduce the risk of neglecting late maturing players.