Longitudinal study on physical fitness characteristics in adolescents with special reference to the determinants of change and associations with perceived health

Abstract

This study entity evaluated how body composition, physical activity (PA) and maturity are associated with physical fitness (PF) status and development during adolescence. We furthermore examined PF development on an individual level and in adolescents with impaired PF. Additionally, we estimated longitudinal associations between PF and self-rated health (SRH). This study entity was designed to provide novel information related to the Finnish national Move! − monitoring system for physical functional capacity and to help interpret the results at the practical level. Data from a 2-year longitudinal observational study were used (2013–2015, n = 970, 12.6 ± 1.3 years, 52.4% girls). Participants completed annual assessments of PF (Move! measurements: cardiorespiratory fitness (20-m shuttle run), muscular fitness (push-up, curl-up), fundamental movement skills (throwing-catching combination test, 5-leaps jump), and flexibility (squat, lower back extension, shoulder stretch)), body composition (bioimpedance), maturity status (Tanner scale), PA (accelerometer, self-reported) and SRH. The main findings reveal that PF develops naturally during adolescence, but that both PF status and development are systematically with practical relevance attenuated by excess adiposity. Low PF tends to be sustained during adolescence in a group and at an individual level. PF is cross-sectionally associated with SRH but does not explain SRH at the 2-year follow-up. In conclusion, PF measured with weight-bearing assessments reflects an individual's ability to perform physically demanding tasks. PF attainment can be supported by healthy weight gain during growth and maturation. PF does not explain future SRH in this study sample, but PA does, and most coherent favourable associations are observed with self-rated PA. It is therefore important to evaluate which variables are the best predictors for health outcomes in specific populations.