Establishing sex-and age-specific percentile curves for some aspects of physical fitness in adolescents from the City of Zagreb

Abstract

The main purpose of the present study was to develop smoothed percentile curves for physical fitness in adolescents aged 15-18 years from the City of Zagreb. In this cross-sectional study, we recruited 1036 secondary-school students aged 15-18 from eleven randomly selected schools (55.3% of girls). As part of physical fitness, we chose 1-minute sit-ups (#), standing long jump (cm) and sit-and-reach (cm) tests using standardized measuring protocol. The sex- and age-specific smoothed percentile curves with 5th, 10th, 25th, 50th, 75th, 90th and 95th percentile for each physical fitness test were calculated using Lambda-Mu-Sigma method. The 50th percentile for 1-minute sit-ups was between 55 and 58 cm in boys, and between 45 and 47.5 cm in girls. For standing long jump, 50th percentile was between 210 and 215 cm in boys and roughly the same (170 cm) in girls. Finally, 50th percentile for sit-and-reach test was between 60 and 65 cm in boys and between 67.5 and 73 cm in girls. This study aimed to establish physical fitness percentile curves for adolescents from the City of Zagreb. Our reference curves might be used to detect adolescents who are at an extreme risk of having 'low' physical fitness status and to implement school-based interventions for physical fitness level enhancement.