A growth curve to model changes in sport participation in adolescent boys.

The aims of this study are twofold: (1) to present the latent growth model, its strategy and usefulness in modelling sport participation over a 6-year period in youngsters (2) and to study the impact of biological maturation in sport participation changes. A standardized sport participation questionnaire using h/week/year as the unit of analysis was applied to 588 Belgium boys 13-18 years of age followed longitudinally for 6 years. Skeletal age was used to estimate biological maturation. Growth curve modelling with robust estimation was used. Sport participation changes showed a curvilinear trend: baseline values (3.18+/-0.13 h/week/year), a linear trend that indicates the rate of change (0.70+/-0.11) and a quadratic trend indicating deceleration, i.e. a change in the rate of change (-0.07+/-0.02) were all statistically significant (P<0.05), as well as inter-individual differences in these three parameters. Up to 16.8 years, the rate of sports participation increased 0.70 h/week/year and then declined. Biological maturation did not show any association with adolescent changes in sport participation.