Sedentary behaviour and clustered metabolic risk in adolescents: the HELENA study.

BACKGROUND AND AIMS: Although sedentary behaviours are linked with mortality for cardiovascular reasons, it is not clear whether they are negatively related with cardio-metabolic risk factors. The aim was to examine the association between time engaged in television (TV) viewing or playing with videogames and a clustered cardio-metabolic risk in adolescents. METHODS AND RESULTS: Sedentary behaviours and physical activity were assessed in 769 adolescents (376 boys, aged 12.5-17.5 years) from the HELENA-CSS study. We measured systolic blood pressure, HOMA index, triglycerides, TC/HDL-c, VO2max and the sum of four skinfolds, and a clustered metabolic risk index was computed. A multilevel regression model (by Poisson) was performed to calculate the prevalence ratio of having a clustered metabolic risk. In boys, playing >4 h/day with videogames (weekend) and moderate to vigorous PA (MVPA) was associated with cardio-metabolic risk after adjustment for age, maternal education and MVPA. In contrast, TV viewing was not associated with the presence of cardio-metabolic risk. CONCLUSION: In boys, playing with videogames may impair cardio-metabolic health during the adolescence. Adolescents should be encouraged to increase their participation in physical activity of at least moderate intensity to obtain a more favourable risk factor profile.

Vitamin D status and physical activity interact to improve bone mass in adolescents. The HELENA Study.

UNLABELLED: The effects of vitamin D concentrations on bone mineral content in adolescents are still unclear. Vitamin D and physical activity (PA) may interact to determine bone mineral content (BMC) in two possible directions; 25(OH)D sufficiency levels improve BMC only in active adolescents, or PA increases BMC in individuals with replete vitamin D levels. INTRODUCTION: The effects of suboptimal 25-hydroxycholecalciferol (25(OH)D) concentrations on BMC in adolescents are still unclear. The main aim of this study was to evaluate the influence of 25(OH)D on BMC in adolescents, considering the effect of body composition, sex, age, Tanner stage, season, calcium and vitamin D intakes, physical fitness and PA. METHODS: Serum 25(OH)D concentrations, anthropometric measurements, dual energy X-ray absorptiometry measurements, calcium and vitamin D intakes, PA and physical fitness were obtained in 100 Spanish adolescents (47 males), aged 12.5-17.5 years, within the framework of the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study. Relations were examined using ANCOVA and regression analyses including BMC as dependent variable. RESULTS: Linear regression of BMC suggested that 25(OH)D concentrations independently influenced total and leg BMC after controlling for age, sex, lean mass, seasonality and calcium intake (B = 0.328, p < 0.05, and B = 0.221, p < 0.05, respectively) in the physically active group. No significant influence of 25(OH)D concentrations on BMC was observed in the inactive group. Significant effect was shown between the interaction of 25(OH)D and PA on BMC for the total body and legs (both p < 0.05). CONCLUSIONS: Vitamin D and PA may interact to determine BMC. 25(OH)D sufficiency levels improve bone mass only in active adolescents, or PA has a positive influence on BMC in individuals with replete vitamin D levels.

Short sleep duration is associated with increased obesity markers in European adolescents: effect of physical activity and dietary habits. The HELENA study.

BACKGROUND: Adequate sleep is a critical factor for adolescent's health and health-related behaviors. OBJECTIVE: (a) to describe sleep duration in European adolescents from nine countries, (b) to assess the association of short sleep duration with excess adiposity and (c) to elucidate if physical activity (PA), sedentary behaviors and/or inadequate food habits underlie this association. DESIGN: A sample of 3311 adolescents (1748 girls) aged 12.5-17.49 years from 10 European cities in Austria, Belgium, France, Germany, Greece, Hungary, Italy, Spain and Sweden was assessed in the Healthy Lifestyle in Europe by Nutrition in Adolescence Study between 2006 and 2008. We measured anthropometric data, sleep duration, PA (accelerometers and questionnaire), television watching and food habits (Food Frequency Questionnaire). RESULTS: Average duration of daily sleep was 8 h. Shorter sleepers showed higher values of BMI, body fat, waist and hip circumferences and fat mass index (P<0.05), particularly in females. Adolescents who slept <8 h per day were more sedentary, as assessed by accelerometry, and spent more time watching TV (P<0.05). The proportion of adolescents who eat adequate amounts of fruits, vegetables and fish was lower in shorter sleepers than in adolescents who slept ≥8 h per day, and so was the probability of having adequate food habits (P<0.05). Correlation analysis indicated that short sleep is associated with higher obesity parameters. CONCLUSIONS: In European adolescents, short sleep duration is associated with higher adiposity markers, particularly in female adolescents. This association seems to be related to both sides of the energy balance equation due to a combination of increased food intake and more sedentary habits.

Associations of muscular and cardiorespiratory fitness with total and central body fat in adolescents: the HELENA study.

OBJECTIVE: to examine the association of healthrelated physical fitness with total and central body fat in adolescents. PARTICIPANTS/METHODS: the present cross-sectional study comprises 363 Spanish adolescents (186 female participants) aged 12.5-17.5 years. We assessed fitness by the 20-m shuttle run test (cardiorespiratory fitness); the handgrip strength, the standing broad jump and the Abalakov tests (muscular strength); and the 4 × 10-m shuttle run test (speed-agility). Total body fat was measured by dual energy x-ray absorptiometry (DXA), BodPod and sum of six skinfolds, and central body fat was measured by DXA at three regions (R1, R2 and R3) and waist circumference. RESULTS: the Abalakov, the standing broad jump, the 4 × 10-m shuttle run and the 20-m shuttle run tests were negatively associated with all markers of total and central body fat in men and women after controlling for age, pubertal status and objectively assessed physical activity (p<0.01). Handgrip strength test was positively associated with waist circumference (p<0.01). CONCLUSIONS: lower body muscular strength and cardiorespiratory fitness are negatively and consistently associated with total and central body fat in adolescents, whereas levels of upper body muscular strength were superior in adolescents with higher levels of central body fat.

Association of objectively assessed physical activity with total and central body fat in Spanish adolescents; the HELENA Study.

OBJECTIVES: To examine the association of objectively assessed physical activity (PA) with markers of total and central body fat in adolescents, and to determine whether meeting the current PA recommendations (> or = 60 min day(-1) of at least moderate intensity PA) is associated with reduced levels of total and central body fat. SUBJECTS/METHODS: A total of 365 Spanish adolescents aged 12.5-17.5 years participated in this cross-sectional study. PA was assessed by accelerometry and expressed as average PA (counts per minute), and min day(-1) of light, moderate, moderate to vigorous (MVPA) and vigorous PA. MVPA was dichotomized into < 60 min day(-1) and > or = 60. Total body fat was measured by DXA, BodPod and the sum of six skinfolds. Central body fat was measured by DXA at three regions (R1, R2 and R3), and waist circumference. RESULTS: All markers of central body fat were negatively associated with vigorous PA (P < 0.01) after controlling for sex, age and pubertal status. Abdominal adiposity measured at R1, R2 and R3 was also negatively associated with MVPA (P < or = 0.001), and with average PA (P < 0.01). All markers of total body fat were negatively associated with vigorous PA (P < 0.01), MVPA (P < 0.01) and average PA (P < 0.05). Adolescents engaged on at least 60 min day(-1) MVPA presented lower levels of total (P < 0.05) and central body fat (P < or = 0.01). CONCLUSIONS: The results suggest that vigorous PA may have a greater effect on preventing obesity in adolescents than does PA of lower intensity, whereas both average PA and at least moderate PA may have an impact on total and central body fat in youth.

Abdominal fat and metabolic risk in obese children and adolescents.

The aim of this study was to investigate fat distribution, mainly abdominal fat, and its relationship with metabolic risk variables in a group of 126 children and adolescents (60 males and 66 females) aged 5.0 to 14.9. According to IOTF criteria, 46 were classified as normal weight, 28 overweight and 52 obese. Weight, height, waist (WC) and hip circumferences were measured. The body mass index (BMI) was calculated. Total body fat, trunkal and abdominal fat were also assessed by dual energy x-ray absorptiometry (DXA). Glucose, insulin, HDL-Cholesterol, triglycerides (TG), ferritine, homocystein and C-reactive protein (CRP) were measured. Obesity status was related with insulin concentrations, CRP, TG and HDL. Obese patients had higher abdominal fat and higher CRP values than overweight and normal subjects. All markers of central body adiposity were related with insulin and lipid metabolism; however, they were not related with homocystein or ferritin. A simple anthropometric measurement, like waist circumference, seems to be a good predictor of the majority of the obesity related metabolic risk variables.

Concurrent validity of a modified version of the International Physical Activity Questionnaire (IPAQ-A) in European adolescents: The HELENA Study.

INTRODUCTION: The International Physical Activity Questionnaire (IPAQ) was developed to measure health-enhancing physical activity in adult populations. This study explores the concurrent validity of a modified version of the long IPAQ (the IPAQ-A) for the assessment of physical activity among adolescents. PARTICIPANTS AND METHODS: In total, 248 healthy adolescents, divided into one older and one younger age group (aged 15-17 years (N=188) and 12-14 years (N=60), respectively) from nine Healthy Lifestyle by Nutrition in Adolescence (HELENA) Study centres across Europe, voluntarily participated in the study. Data on total physical activity, as well as activities in different intensities derived from the IPAQ-A, were compared using Spearman's correlation coefficient and Bland-Altman analysis, with data from an accelerometer. Tertiles of total physical activity for the IPAQ-A and the accelerometer were compared using Kendall's tau-b. RESULTS: For the older age group, significant correlations between the instruments were found for time spent walking, for moderate and vigorous activities as well as for total physical activity (Rs=0.17-0.30, P<0.05). No significant correlations were found for any of the variables studied in the younger age group. Kendall's tau-b showed low but significant correlations for tertiles of total physical activity (P<0.001). CONCLUSIONS: The IPAQ-A has reasonable validity properties for assessing activities in different intensities and for total physical activity in healthy European adolescents aged 15-17 years. For adolescents aged 14 years and younger, the correlations were unsatisfactorily low and objective methodology, such as accelerometry, may be the appropriate alternative.

Reliability of health-related physical fitness tests in European adolescents. The HELENA Study.

OBJECTIVE: To examine the reliability of a set of health-related physical fitness tests used in the European Union-funded Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Study on lifestyle and nutrition among adolescents. DESIGN: A set of physical fitness tests was performed twice in a study sample, 2 weeks apart, by the same researchers. PARTICIPANTS: A total of 123 adolescents (69 males and 54 females, aged 13.6+/-0.8 years) from 10 European cities participated in the study. MEASUREMENTS: Flexibility, muscular fitness, speed/agility and aerobic capacity were tested using the back-saver sit and reach, handgrip, standing broad jump, Bosco jumps (squat jump, counter movement jump and Abalakov jump), bent arm hang, 4 x 10 m shuttle run, and 20-m shuttle run tests. RESULTS: The ANOVA analysis showed that neither systematic bias nor sex differences were found for any of the studied tests, except for the back-saver sit and reach test, in which a borderline significant sex difference was observed (P=0.044). The Bland-Altman plots graphically showed the reliability patterns, in terms of systematic errors (bias) and random error (95% limits of agreement), of the physical fitness tests studied. The observed systematic error for all the fitness assessment tests was nearly 0. CONCLUSIONS: Neither a learning nor a fatigue effect was found for any of the physical fitness tests when repeated. The results also suggest that reliability did not differ between male and female adolescents. Collectively, it can be stated that the reliability of the set of physical fitness tests examined in this study is acceptable. The data provided contribute to a better understanding of physical fitness assessment in young people.

The prevalence of metabolically healthy obesity: a systematic review and critical evaluation of the definitions used.

We performed a systematic review of the prevalence of metabolically healthy obesity (MHO). Medline, Web of Science and EMBASE were searched for original articles from inception to November 2013. Only prospective and cross-sectional studies were included. After screening 478 titles, we selected 55 publications, of which 27 were population-based studies and were used in the narrative synthesis. From the 27 studies, we identified 30 definitions of metabolic health, mainly based on four criteria: blood pressure, high-density lipoprotein cholesterol, triglycerides and plasma glucose. Body mass index ≥30 kg m(-2) was the main indicator used to define obesity (74% of the studies). Overall, MHO prevalence ranged between 6% and 75%. In the studies that stratified the analysis by sex, prevalence was higher in women (seven out of nine studies) and in younger ages (all four studies). One-third of the studies (n = 9) reported the response rate. Of these, four reported a response rate of ≥70% and they showed MHO prevalence estimates between 10% and 51%. The heterogeneity of MHO prevalence estimates described in this paper strengthens calls for the urgent need for a commonly established metabolic health definition.

Sleep time and cardiovascular risk factors in adolescents: the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study.

OBJECTIVE: We aimed to examine the association between adolescents' sleep time and a cardiometabolic risk score. A second aim was to examine associations between sleep time and individual cardiometabolic risk factors. METHODS: Adolescents (N=699; ages, 12.5-17.5 years) participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study were examined. Sleep time was reported by a questionnaire. Physical activity (PA) was assessed by accelerometry (n=497). Cardiometabolic risk factors measurements included insulin resistance, blood pressure, adiposity markers, cardiorespiratory fitness, and blood lipids. A cardiovascular disease risk score was computed. Associations were examined by a multilevel regression analysis (linear for individual risk factors and Poisson for the clustered risk score). RESULTS: For school days no association was found between sleep time and cardiometabolic risk factors. At weekend days, the prevalence ratio (PR) of having a clustered risk score increased by 15% for each additional hour of sleep controlling for age, sex, and socioeconomic status (SES); however, the prevalence disappeared when adjusting for PA. CONCLUSIONS: In European adolescents sleep time is not associated with cardiometabolic risk factors when important confounders are considered. Future research about sleep cardiovascular risk factors should register other sleep dimensions (sleep patterns or disturbances) to provide a better insight in this scientific field.

Physical activity does not attenuate the obesity risk of TV viewing in youth.

OBJECTIVE: This study aimed to examine the association of television (TV) time, the frequency of meals while watching TV and the presence of TV set in the bedroom with total and abdominal obesity and to assess whether physical activity (PA) attenuates the obesity risk of TV viewing. METHODS: Cross-sectional data were obtained from 2200 adolescents (46% boys) from 10 European cities, The Healthy Lifestyle in Europe by Nutrition in Adolescence study, between 2006 and 2007. TV viewing, PA (by accelerometry) and body composition were measured. Binary logistic regression analyses were performed. RESULTS: Even adjusting by vigorous PA, TV in the bedroom (odds ratio [OR]: 1.33, 95% confidence interval [CI], 1.01-1.74) and >4 h d(-1) TV during week days (OR: 1.30, 95% CI, 1.02-1.67) (in boys) and eating every day with TV (OR: 1.18, 95% CI, 1.07-1.30) and >2 h d(-1) TV during weekend days (OR: 1.68, 95% CI, 1.25-2.26) (in girls) were significantly associated with total obesity. Likewise, in both sexes, having a TV set at bedroom was significantly associated with abdominal obesity. CONCLUSIONS: Adolescents spending excessive TV time are prone to obesity independently of their PA levels. Families should put TV sets out of adolescents' bedroom and keep TV sets off during meal times.

Bone mass and bone metabolism markers during adolescence: The HELENA Study.

BACKGROUND/AIMS: The assessment of bone mineral content (BMC) and density (BMD) status in children and adolescents is important for health and the prevention of diseases. Bone metabolic activity could provide early information on bone mass development. Our aim was to describe bone mass and metabolism markers according to age and Tanner stage in adolescents. METHODS: Spanish adolescents (n = 345; 168 males and 177 females) aged 12.5-17.5 years participated in this cross-sectional study. Body composition variables were measured by dual-energy X-ray absorptiometry. Serum osteocalcin (n = 101), aminoterminal propeptide of type I procollagen (n = 92) and ß-isomerized C-telopeptides (ß-CTX, n = 65) and urine samples (ß-CTX; n = 237) were analyzed by electrochemiluminescence immunoassay. RESULTS: Analysis of covariance showed that females had higher values for BMC and BMD in most of the regions. Both males and females had a significant decrease in bone markers while sexual maturation increases (all p < 0.05). Males had an increased bone turnover compared to females (all p < 0.05, except for urine ß-CTX in Tanner ≤IV). CONCLUSION: Our results support the evidence of dimorphic site-specific bone accretion between sexes and show an increased bone turnover in males, suggesting higher metabolic activity.

Secular trends in health-related physical fitness in Spanish adolescents: the AVENA and HELENA studies.

We analysed the secular trends in health-related physical fitness in Spanish adolescents between 2001-2002 and 2006-2007. Two representative population studies were conducted 5 years apart in adolescents (12.5-17.5 years) from Zaragoza (Spain) that participated in the AVENA study in 2001-2002 and in the HELENA-CSS study in 2006-2007. Both studies used the same tests to assess physical fitness: the handgrip strength, bent arm hang, standing broad jump, 4×10m shuttle run and 20m shuttle run tests. Performance in 4×10m shuttle run and 20m shuttle run tests was higher in 2006-2007 (Cohen's d ranging from 0.2 to 0.4, p<0.05), whereas performance in handgrip strength and standing broad jump tests was lower in 2006-2007 (Cohen's d ranging from 0.3 to 1.1, p<0.001). Adjustment for age, pubertal status, fat mass, fat free mass and parental education did not alter the results. The odds ratio (OR) of meeting the FITNESSGRAM Standards for healthy cardiorespiratory fitness was higher in 2006-2007 in both boys (OR, 95% CI: 2.123, 1.157-3.908) and girls (OR, 95% CI: 2.420, 1.377-4.255). The results indicate that levels of both speed/agility and cardiorespiratory fitness were higher in 2006-2007 than in 2001-2002, whereas muscular strength components were lower in 2006-2007.

Extracurricular physical activity participation modifies the association between high TV watching and low bone mass.

OBJECTIVES: To examine whether different sedentary behaviours are associated with the risk of low bone mineral content in adolescents, and if so, whether extracurricular physical-sporting activity influences this association. MATERIALS AND METHODS: A total of 277 adolescents from Zaragoza (168 females and 109 males) aged 13.0-18.5 yr within frame work of the multicentre AVENA study participated in this study. Bone mineral content (BMC), lean mass, and fat mass were measured with DXA. Physical activity and sedentary independent variables: participation in extracurricular physical-sporting activity (PA), h/d of television watching, playing video/computer games during school days and on weekend days and doing homework/studying. They all were assessed by questionnaire. The main outcome was low BMC, as defined by BMC Z-score for age and sex < percentile 10. Logistic regression was used to test the interaction and association of PA and sedentary variables with low BMC, after controlling for confounders like height, maturational status or lean mass. RESULTS: Among the sedentary variables studied, only television watching > or =3 h/d was associated with an increased risk for low BMC in males (OR, 95% CI: 7.01, 1.73 to 28.40), after controlling for sexual maturation. When PA was in the models, television watching was not any longer associated with low BMC, while PA was so (OR, 95% CI: 0.23, 0.09 to 0.55). Involvement in such activity reduced the risk of low bone mass by 76% (P<0.01) independently of body mass, height and fat mass, but not of the lean mass. CONCLUSION: Watching television for 3 or more h/d seems to be associated with an increased risk for low BMC in male adolescents. However, this association is mediated by participation in PA, suggesting that negative consequences of excessive television watching on adolescent bone health could be counteracted by sport participation. Longitudinal data and randomized controlled trials will confirm or contrast our findings.

Marcadores del metabolismo óseo en adolescentes españoles. Estudio HELENA / Bone metabolism markers in Spanish adolescents. The HELENA Study

Objetivo del trabajo: Describir el metabolismo óseo a lo largo de la adolescencia, según la edad y el desarrollo puberal en adolescentes. Material (pacientes) y método: El análisis de los marcadores de metabolismo óseo se realizó a partir de muestras de suero con osteocalcina (OC; n=95), propeptido aminoterminal del procolágeno de tipo 1 (P1NP; n=87) y C-telopépidos Beta-isomerizados (Beta-CTX; n=65)] y de orina [Beta-CTX (n=209)] que se analizaron mediante inmunoensayo de electroquimioluminiscencia. Resultados: La concentración de los marcadores de formación y resorción ósea eran más altos en los chicos y las chicas menos desarrollados comparado con los grupos de mayor desarrollo puberal (p < 0.05), excepto ‚-CTX (en orina) en chicos (p = 0,105). Sin embargo, la osteocalcina no mostró una tendencia significativa en chicos (p = 0.264) al agrupar por edades. Los chicos adolescentes presentaron un remodelado óseo superior al de las chicas. Conclusiones: Los chicos adolescentes presentaron un remodelado óseo superior al de las chicas, lo que sugiere una mayor actividad metabólica de éstos durante la adolescencia (AU)

Objetives: To describe bone metabolism throughout adolescence, according to age and pubertal development. Material and methods: Bone metabolism markers were analysed on serum [Osteocalcin (n=95), aminoterminal propeptide of type I procollagen (PINP, n=87) and ‚-isomerised C-telopeptides (Beta-CTX, n=65)] and urine samples [Beta-CTX (n=209)] by electrochemiluminescence immunoassay. Results: bone formation and resorption biomarkers concentration were higher in males and females with lower pubertal development compared with those groups with higher development (p < 0.05), except urine ‚- CTX in males (p = 0,105). Osteocalcin did not show a significant trend in males (p = 0.264) when grouping by age. Males had an increased bone turnover compared to females. Conclusions: Males showed an increased bone turnover compared to females, suggesting higher metabolic activity during adolescence (AU)

Abdominal fat and metabolic risk in obese children and adolescents

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The aim of this study was to investigate fat distribution, mainly abdominal fat, and its relationship with metabolic risk variables in a group of 126 children and adolescents (60 males and 66 females) aged 5.0 to 14.9. According to IOTF criteria, 46 were classified as normal weight, 28 overweight and 52 obese. Weight, height, waist (WC) and hip circumferences were measured. The body mass index (BMI) was calculated. Total body fat, trunkal and abdominal fat were also assessed by dual energy x-ray absorptiometry (DXA). Glucose, insulin, HDL-Cholesterol, triglycerides (TG), ferritine, homocystein and C-reactive protein (CRP) were measured. Obesity status was related with insulin concentrations, CRP, TG and HDL. Obese patients had higher abdominal fat and higher CRP values than overweight and normal subjects. All markers of central body adiposity were related with insulin and lipid metabolism; however, they were not related with homocystein or ferritin. A simple anthropometric measurement, like waist circumference, seems to be a good predictor of the majority of the obesity related metabolic risk variables (AU)

Consumo de televisión y nivel socioeconómico en niños y adolescentes / Television consumption and socioeconomic level in children and adolescent

Antecedentes. El sedentarismo en niños y adolescentes, principalmente el consumo de televisión, está muy relacionado con determinantes medioambientales como el nivel socioeconómico. Los comportamientos sedentarios establecen estilos de vida que predisponen a obesidad. Objetivo: Pretendemos estudiar si un nivel socioeconómico bajo predispone al sedentarismo, el cual es factor de riesgo de obesidad. Material y métodos: Realizamos un estudio descriptivo transversal de una muestra representativa de los colegios del Área sanitaria 3 de Zaragoza. Doscientos sesenta sujetos, 137 varones de 13,30 ± 1,63 años de edad y 123 mujeres de 13,36 ± 1,84 contestaron voluntariamente un cuestionario para valorar el patrón de actividades sedentarias mediante: las horas de televisión, de ordenador, de estudio y deberes, el medio de transporte usado para ir al colegio-instituto y las horas de sueño. Se valoró el nivel socio-económico según el nivel de estudios e ingresos de madre y padre por separado. En varones se muestra significativamente que, a menor nivel de estudios de la madre y del padre y a menores ingresos del padre, hay un mayor número de horas viendo la televisión. Además los niños emplean más tiempo en el ordenador. Las mujeres emplean más tiempo en estudiar o hacer los deberes, aunque no guarda relación con el nivel de estudios o ingresos de los padres. Conclusiones: No hay diferencias entre los dos sexos respecto al consumo de televisión aunque un gran porcentaje de los niños de nuestra muestra sobrepasa las recomendaciones de la Academia Americana de Pediatría de menos 2 horas de televisión al día. Los niños varones con menor estatus socioeconómico emplean más tiempo en hábitos sedentarios (AU)

Sedentary behaviour in children and adolescent, mainly television consumption, are related with environmental factors such as socioeconomic status. High sedentary leisure time may establish behavioral patterns that predispose to obesity. Objetive: We aim to test whether people with a low socioeconomic status tend to be more inactive. Materials and methods: The study used a cross-sectional design for a representative schools of the 3rd sanitaria area in Zaragoza. A questionnaire was answered by a representative sample for 260 subjects: 137 boys (13.30 ± 1.63 years old) and 123 girls (13.36 ± 1.84 years old). Behavioral variables were evaluated: television and computer use, active commuting to school, hours of study and homework and sleeping time. Additionally, socioeconomic variables, such as, father and mother level of studies and incomes were also evaluated. Results: In boys, low level of mother and father studies and low level of father incomes was significative associated with more television viewing. In addition, they were more computer users. Girls spent more time on studying and doing homework, but it was not associated with parents´ studies or incomes. Conclusions: there is no evidence of television viewing separately by gender. In our sample both do not meet the recommendation of the American Academy of Paediatrics of less that 2 hours per day. Boys with low socioeconomic status used more time in sedentary activities (AU)