[Determinants of health in adolescence: cardiorespiratory fitness and body composition].

Introduction: cardiorespiratory fitness and body composition are determining indicators of health status during adolescence. The objective of the study was to analyze the relationship of both parameters with indicators of mental and psychosocial health, lifestyle habits, and sociodemographic variables, establishing their predictive factors. Method: a cross-sectional study was conducted with a representative sample of 761 students (14.51 ± 1.63 years old) from 25 educational centers in a northern region of Spain. Body mass index, maximum oxygen uptake, health-related quality of life, self-esteem, hours of nightly sleep, adherence to the Mediterranean diet, physical activity engagement, academic performance, and different sociodemographic factors were analyzed for all participants. Results: the results determined that being a boy, being younger, sleeping fewer hours at night, and presenting a lower academic performance were predictors of suffering from obesity, while being younger and being a migrant were predictors of being overweight. On the other hand, lower physical activity engagement, poorer academic performance, being a migrant, and not practicing extracurricular sports activities were predictive factors of cardiorespiratory fitness in the risk zone. In addition, the environment for performing physical activity and socioeconomic level also showed associations with cardiorespiratory fitness. Conclusions: given the influence of body composition and cardiorespiratory fitness on the physical and psychosocial health of adolescents, promotion strategies are required that take into account the identified predictors, with special attention to promoting healthy lifestyles.