Longitudinal changes in physical fitness performance in youth: A multilevel latent growth curve modeling approach

Using a multilevel latent growth curve modeling (LGCM) approach, this study examined longitudinal change in levels of physical fitness performance over time (i.e. four years) in young adolescents aged from 12-13 years. The sample consisted of 6622 students from 138 secondary schools in Singapore. Initial analyses found between-school variation on fitness test scores with intra-class correlations ranging from 0.02-0.19. Subsequent multilevel growth curve analyses revealed a quadratic trend of the longitudinal data across five stations of performance tests, with significant within-school student variability in change over time. The result of the multilevel LGCM showed that there were strong school effects on all of the physical fitness performances, in addition to inter- and intra-individual differences.