El presente estudio persigue como principal objetivo concretar las actividades de tiempo libre practicadas en una muestra de escolares, así como los hábitos de alimentación y la relación entre éstos y el tiempo en familia. La muestra la componen 392 escolares de 11 a 17 años de un municipio onubense. Se ha administrado el cuestionario Health Behaviour in School-aged Children (HBSC-2010), en su versión española. Para este trabajo, se utilizaron las variables alimentación, actividad física y tiempo libre y familia. Se realizó un análisis descriptivo de las variables, el estadístico T de Student para comparar grupos (chicos y chicas), y se utilizó una ANOVA para comparar dichas variables por curso. Para analizar las asociaciones entre la actividad física (AF), el tiempo libre y el ocio familiar se utilizó el coeficiente de la correlación de Pearson. Los resultados mostraron que el 27% practica actividad física a diario, las chicas practican menos que los chicos y los estudiantes de la Educación Secundaria Obligatoria (ESO), practican menos que los de Primaria. Aunque conforme aumenta la edad realizan más actividades junto a la familia, destacando el deporte. Abstract. The main purpose of this study is to analyze and define leisure activities and eating habits within a sample of students, as well as to evaluate the relationship between these variables and the time spent interacting with their family. The sample consisted of 392 students aged 11 to 17 years in a town in the province of Huelva, Spain. The questionnaire applied was the Spanish version of the Health Behaviour in School-aged Children (HBSC-2010). For this work, we have used the variables health, nutrition, physical activity and leisure, and family. We performed a descriptive analysis of the variables, a Student t statistic to compare groups (boys and girls), and ANOVA was used for comparing these variables by course. Pearson's correlation coefficient was used in order to analyze associations between physical activity, spare time, and family leisure. The results show that 27% of the students in the sample usually practice physical activity on a daily basis; girls were less likely to practice than the boys; finally, teenagers at higher levels of compulsory education are less prone to do sport than primary school students. As their age increases, they tend to do more activities with the family, particularly sport.

-The influence of biological maturation and physical activity (PA) on the differences of body composition in adolescents have been little studied. The purpose of this study was to examine if PA and maturity status were sex-specific determinant factors in the adolescents' body composition. Ninety-four adolescents (50 boys and 44 girls) were evaluated. All anthropometric measures were obtained according to ISAK procedures, bone age was estimated by the TW3 method, and PA was assessed with Actigraph® GT1M, over seven consecutive days. Maturity status explained 33% of the body mass index (BMI) and waist circumference (WC) and 31% of the sagittal abdominal diameter (SAD) in boys. In girls, maturity status explained 27% of the waist-to-hip ratio (WHR), moderate PA explained 17% of the BMI and 12% of the WC, and moderate to vigorous PA explained 11% of the SAD. These results seem to indicate that the determinant factors of the adolescents' body composition are sex-specific. Maturity status was the main predictive factor in boys and interacted with PA in girls. Our findings support the evidence that researchers need to consider biological maturity when explaining body composition changes in adolescents. Key words: Adolescent; Body composition; Maturity; Physical activity. Resumo -A influência da maturação biológica e atividade física (AF) nas diferenças de composição corporal em adolescentes tem sido pouco estudada. O objetivo deste estudo foi examinar se, na composição corporal dos adolescentes, a AF e a maturidade eram fatores determinantes específicos do sexo. Foram avaliados noventa e quatro adolescentes (50 meninos e 44 meninas). Todas as medidas antropométricas foram obtidas de acordo com os