Short-term tracking of performance and health-related physical fitness in girls: The Healthy Growth in Cariri Study

The main purpose of this study was to track the performance and health-related physical fitness of girls from Brazil's Cariri region. In the "Healthy Growth in Cariri Study", 294 girls from public and private schools were divided into four age cohorts--8, 10, 12, and 14 years--and followed for three consecutive years, with an assessment every 6 months. Shuttle run, hand grip, standing long jump, trunk lift, curl-up, 12-min run, and fatness were used to rate physical fitness performance and health-related components on each of six occasions. Tracking was done in a stepwise manner, using auto-correlation, by modelling the individual history of change in performance of each girl, and using Foulkes and Davies' γ-coefficient. SPSS 18.0 and TIMEPATH were used for data analysis. Auto-correlations evidenced low-to-moderate values in almost all components of performance and health-related physical fitness. Intra-individual tracking analysis showed large variation in all fitness components as a result of a wide spread in individual history of change in fitness performance. Population estimates of γ were low in all tests. Our results show low-to-moderate tracking of physical fitness components of girls. A wide range of intra-individual and inter-variability in fitness development was observed.