Development of physical performance tasks during rapid growth in brazilian children: The cariri healthy growth study

Growth and physical performance scores were studied around three years of attainment of peak height velocity (PHV). We aimed to estimate the age at peak velocity, or at peak rate, in physical performance tasks, and sex-differences when aligned by biological age. A total of 131 boys and 123 girls, 8 to 14 years of age were recruited from the Cariri region of Brazil. A mixed longitudinal design was used with four overlapping age cohorts: 8, 10, 12, and 14 years, followed for three years, with measurements performed at 6 month intervals. Height, 12 min run (12mR), handgrip strength (HG), standing long jump (SLJ), and shuttle run (SR) velocities were estimated using a non-smooth mathematical procedure. Age at PHV was 13.4 ± 1.6 years in boys compared with 12.2 ± 2.3 years in girls. Maximal velocity in SLJ was attained 6 and 3 months prior to PHV in boys and girls, respectively. For HG, peaks were attained 9 months after PHV in boys and 15 months after PHV in girls. Maximal velocity in 12mR was attained 6 months before PHV in boys and at PHV in girls, whereas a peak in SR occurred 12 months after PHV in both sexes. In conclusion, dynamic changes in physical performance relative to PHV appear similar in both sexes, although sex differences were evident in some motor tests.