Relação entre indicadores de risco à saúde e componentes do somatótipo consoante atividade física em crianças / Relación entre indicadores de riesgo para la salud y componentes del somatótipo según la actividad física en niños / Relationship between health risk indicators and somatotype components according to physical activity in children

Este estudo analisou a relação entre indicadores de risco à saúde e as componentes do somatótipo consoante os níveis de atividade física em crianças. Trata-se de uma pesquisa epidemiológica de base escolar, composta por 168 crianças (6 a 11 anos) de ambos os sexos. Informações demográficas foram obtidas. Avaliações antropométricas (estatura; massa corporal; pregas de adiposidade subcutânea; perímetros do braço contraído, cintura, quadril e panturrilha), pressão arterial sistólica e diastólica, e atividade física (ativo; inativo) foram mensuradas. O somatótipo, razão cintura-quadril e razão cintura-estatura foram calculados. Análise de comparação, correlação e regressão linear múltipla foram realizadas, considerando intervalo de confiança de 95%. Meninos apresentaram maior número de passos, razão cintura-quadril e cintura-estatura. Crianças ativas eram mais velhas, possuíam maior perímetro de cintura, quadril e pressão arterial sistólica. No grupo fisicamente ativo, o sexo esteve associado diretamente ao perímetro de cintura e razão cintura-estatura, enquanto a idade associou-se com a perímetro de quadril e pressão arterial diastólica. Nas crianças inativas, todas as variáveis preditoras (exceto para a variável sexo em relação ao perímetro de quadril) mostraram-se significativas para o perímetro da cintura e quadril, explicando, conjuntamente, ~83% e 85% da expressão destas variáveis, respectivamente. A relação entre indicadores de risco à saúde e as componentes do somatótipo foi maior em crianças inativas. Independentemente do nível de atividade física, a endomorfia mostrou relação significativa com os componentes de saúde, com maior efeito no grupo inativo, tendo em vista a associação com a composição corporal dos sujeitos.

Este estudio analizó la relación entre indicadores de riesgo para la salud y los componentes del somatótipo según los niveles de actividad física en niños. Se trata de una investigación epidemiológica, compuesta por 168 niños (6 a 11 años) de ambos sexos. Fueron mensuradas: evaluaciones antropométricas (estatura; masa corporal; pliegues de adiposidad subcutánea; perímetros del brazo contraído, cintura, cuadril y pantorrilla), presión arterial sistólica y diastólica, y actividad física (activo/inactivo); el somatótipo, a través del cálculo de: razón cintura-cuadril y razón cintura-estatura. Se realizó el análisis de comparación, correlación y regresión lineal múltiple, considerando intervalo de confianza del 95%. Los niños presentaron mayor número de pasos, razón cintura-cuadril y cintura-estatura. Los niños activos eran mayores, tenían mayor perímetro de cintura, cuadril y presión arterial sistólica. En el grupo físicamente activo, el sexo estuvo asociado directamente al perímetro de cintura y razón cintura-estatura, mientras que la edad se asoció con el perímetro de cuadril y presión arterial diastólica. En los niños inactivos, todas las variables predictoras (excepto para la variable sexo con relación al perímetro de cuadril) se mostraron significativas para el perímetro de la cintura y cuadril, explicando, conjuntamente, ~83% y 85% de la expresión de estas variables, respectivamente. La relación entre indicadores de riesgo para la salud y los componentes del somatotipo fue mayor en niños inactivos. Independientemente del nivel de actividad física, la endomorfia mostró una relación significativa con los componentes de salud, con mayor efecto en el grupo inactivo, con vistas a la asociación con la composición corporal de los sujetos.

This study analysed the relationship between health risk indicators and somatotype components according to physical activity levels in children. This epidemiological and school-based research comprised 168 children of both sexes (56% boys), aged between 6 to 11 years. Demographic information (sex, age) was obtained. Anthropometric information (body height; body mass; contracted arm, waist, hip, and calf circumferences), body composition (subcutaneous adiposity and somatotype), systolic and diastolic blood pressure, and physical activity level (active; inactive) were measured. The waist-hip ratio and waist-to-height ratio were computed. Comparison, correlation, and multiple linear regression analysis were performed, considering 95% of the confidence interval. Boys presented higher values for physical activity, waist-hip, and waist-to-height ratio. Active children were older, had a larger waist and hip circumference, and higher systolic blood pressure. Among the active group, sex was associated with waist circumference and waist-to-height ratio, while age was associated with hip circumference and diastolic blood pressure. Among inactive children, all predictors (except for sex for hip circumference) were significantly associated with waist and hip circumferences, explaining ≅83% and 85% of the expression of these variables, respectively. The relationship between health risk indicators and somatotype components was higher among inactive children. Regardless of the physical activity level, the endomorphic component shows a significant relationship with health components, with a higher effect among the inactive group, considering the body composition association.

Asociación entre comportamientos de riesgo y sobrepeso en adolescentes: análisis de clases latentes / Association between risk behaviors and overweight in adolescents: a latent classes analysis / Associação entre comportamentosde risco e excesso de peso em adolescentes: análise de classes latentes

RESUMEN Este estudio tuvo como objetivo describir la agregación de comportamientos del estilo de vida en adolescentes brasileños e identificar la asociación de estas agregaciones con el exceso de peso. Se ha utilizado información sobre el consumo alimentario, tiempo frente a la televisión y práctica de actividad física de una muestra compuesta por 14141 adolescentes, de ambos sexos, con edades entre 11 y 17 años, procedente de la Encuesta Nacional de Salud del Escolar (2015), que fueron divididos en tres clases: físicamente activos (FA), comportamiento de riesgo (CR) e inactivos físicamente con alimentación saludable (IA). Los resultados mostraron que las niñas y adolescentes mayores tienen menos probabilidades de desarrollar exceso de peso en comparación con los niños y adolescentes más jóvenes, así como los sujetos pertenecientes a la clase CR, que tienen menos probabilidades de presentar exceso de peso, mientras que los adolescentes de clase IA tienen más probabilidades en comparación con la FA. Se puede concluir que la adopción de hábitos saludables parece ejercer una influencia importante en cuanto al resultado de sobrepeso, ya que, no obstante, la adopción de alimentación "no saludable" es prevalente en la clase CR, los niveles de actividad física se asemejan a la clase FA, que puede mitigar los efectos de los comportamientos negativos relacionados con la alimentación.

ABSTRACT This study aimed to describe the cluster of lifestyle behaviors among Brazilian adolescents and to identify the association of these clusters with overweight. Information related to food consumption, TV time and physical activity were used, from a sample of 14141 adolescents of both sexes, aged between 11 and 17 years, from the National School Health Survey (2015), who were split into three classes: physically active (FA), risky behavior (CR), and physically inactive with healthy eating (AI). Results showed that girls and older adolescents have less chances to be overweight when compared to boys and younger adolescents, respectively. Moreover, subjects classified as CR have less chances of being overweight, whereas those classified as AI are more prone to be overweight compared to those belonging to FA class. We conclude that the adoption of healthy habits seems to be of relevance in the expression of overweight, because although the high prevalence of "unhealthy" diet among subjects from the CR class, their physical activity levels are similar to their peers from the FA class, which may mitigate the impacts unhealthy behaviors associated with food consumption.

RESUMO Este estudo teve como objetivo descrever a agregação de comportamentos de estilo de vida em adolescentes brasileiros e identificar a associação dessas agregações com o excesso de peso. Informações sobre consumo alimentar, tempo em frente à televisão e prática de atividade física de uma amostra composta por 14141 adolescentes, de ambos os sexos, com idade entre 11 e 17 anos, da Pesquisa Nacional de Saúde do Escolar (2015), que foram divididos em três classes: fisicamente ativo (AF), comportamento de risco (CR) e fisicamente inativo com alimentação saudável (IA). Os resultados mostraram que meninas e adolescentes mais velhos são menos propensos a desenvolver excesso de peso em comparação com crianças e adolescentes mais novos, assim como os sujeitos pertencentes à classe CR, que são menos propensos ao excesso de peso, enquanto os adolescentes da classe IA são mais propensos em relação aos AF. Pode-se concluir que a adoção de hábitos saudáveis parece ter influência importante no resultado do excesso de peso, pois, no entanto, a adoção de dietas "não saudáveis" é prevalente na classe CR, os níveis de atividade física são semelhantes aos da classe AF, o que pode atenuar os efeitos de comportamentos negativos relacionados à alimentação.

Running performance of non-professional female runners from different Brazilian states: the role of environmental characteristics

Abstract Aims: (i) to compare the running performance of non-professional female runners from different Brazilian states; (ii) to estimate the relationship between environmental state-related variables and running performance; and (iii) to analyze the mediation role of training commitment in the relationship between the environment and running performance. Methods: A total of 418 non-professional female runners were sampled from the five Brazilian regions. An online questionnaire was used for data collection and included self-reported information about age, body weight, body height, place of residence, training volume, and running pace. Environmental characteristics were based on the Census 2010 and included percentages of public illumination, asphalt, sidewalks, and green areas for state capital cities. Linear regression, Pearson correlation, and mediation analysis were performed using SPSS 26, at a 95% confidence interval. Results: The fastest women were from the Rio Grande do Sul. Significant differences were observed between Rio Grande do Sul and Rio Grande do Norte (β= 45.79; 95%CI = 16.86 − 74.73), Distrito Federal (β = 34.55; 95%CI = 1.87−67.24), and Sergipe (β = 35.34; 95%CI = 14.09−56.60). A negative relationship was observed between running pace with green areas (r = −0.206; 95%CI = −0.305 − −0.110) and training volume (r = −0.343; 95%CI = −0.427−0.167). Training volume explained 23% of the relationship between the percentage of green areas and running performance. Conclusion: The fastest runners were from the Rio Grande do Sul. Higher percentages of green areas can favor performance, which is partly mediated by increased training volume.

Onde estão os melhores corredores do Brasil? / Where are the best road runners in Brazil?

A análise do desempenho esportivo deve ser feita através de uma perspectiva que contemple a influência de diversos fatores. Neste contexto, fatores socioeconômicos e demográficos do estado apresentam-se, também, como preditores no desempenho esportivo, sobretudo em esportes que aparentemente são considerados "baratos e de fácil acesso" como é o caso da corrida de rua. Sendo assim, o propósito do trabalho é apresentar uma descrição da distribuição dos melhores corredores de rua a nível nacional, e verificar a relação entre a representatividade no ranking e variáveis relacionadas ao estado, sendo elas: índice de desenvolvimento humano, tamanho da população, rendimento mensal e produto interno bruto. Para verificação da distribuição dos corredores no país, foi verificada a frequência de atletas no ranking, conforme estado. A correlação de Sperman foi utilizada para verificar a relação existente entre as variáveis relacionadas ao estado e a presença dos corredores no ranking, sendo considerado p<0,05. Foi observada uma maior representatividade das regiões Sudeste e Sul, comparativamente às demais regiões do Brasil, para além do fato de que houve correlação positiva e significativa entre as variáveis "tamanho da população" e "produto interno bruto" com os estados representados no ranking. Deste modo, conclui-se que àquelas regiões que possuem melhores valores desses indicadores são mais propensas a obterem uma maior quantidade de atletas no ranking por fatores como: maior número de atletas praticantes da modalidade e fatores econômicos que sustentam os seus praticantes durante a dedicação ao esporte e que culminam em uma maior representatividade relativamente às demais regiões. (AU)

The analysis of sport performance should be performed through different predictors. Taking this into account, socioeconomic and demographic factors from the state where the person lives can be seeing as relevant determinants of the sport performance, especially in sports considered as "cheap and accessible", such as road running race. The purpose of the present study is to describe the distribution of the best road runners in Brazil, and to verify the relationship between the representativeness in the national ranking with variables related to the state, namely: human development index, state population size, monthly income, and gross domestic product. To determine the road runners' distribution across the country, the frequency of the runners presented in the ranking was reported according to Brazilian states. The Sperman correlation (r) was computed to verify the relationship between state predictors and the presence of runners in the ranking, with the significance level of p<0.05. It was observed a higher representativeness of the South and Southeast regions, compared with the other Brazilian geographical regions; in addition, a positive and significant correlation was observed between the variables "state population size" and "gross domestic product" with the states presented in the ranking. In conclusion, those regions with higher values in these indicators are more prone to have more runners in the ranking, given the highest number of subjects enrolled in this sport as well as socioeconomic factors that support the athletes during their practice, leading to a higher representativeness of this regions in relation to the other ones. (AU)

Deslocamento ativo em adolescentes: prevalência e preditores associados ao trajeto casa-escola / Active commuting among adolescents: prevalence and associated predictors at the home-school route

O objetivo do presente estudo é descrever a prevalência de deslocamento ativo entre adolescentes brasileiros no trajeto casa-escola considerando as unidades federativas e regiões do país, e verificar os preditores associados a esse comportamento. A amostra foi composta por 99.967 adolescentes (ambos os sexos; média de idade 14,24 anos) que participaram da Pesquisa Nacional de Saúde do Escolar em 2015. Para o estudo, foram consideradas informações relativas ao deslocamento ativo no percurso casa-escola (frequência e duração), aspecto socioeconômico e percepção de segurança no trajeto para a escola, sendo obtidas através de questionário. A análise estatística foi realizada por meio da regressão logística binária. Foi observado que 44,4% dos jovens realizam o deslocamento ativo (ir e voltar da escola através do uso de bicicleta/caminhada, pelo menos cinco dias na semana), sendo que a região Sudeste apresenta a maior porcentagem de adolescentes que aderem à tal prática (46,4%). Ser do sexo masculino (OR = 1,19), mais "novo" (OR = 0,89) e despender mais tempo por semana em deslocamento ativo (OR = 1,01) aumentam as chances de o adolescente realizar o deslocamento ativo em seu trajeto para a escola; enquanto que possuir carro em casa (OR = 0,72) e perceber o trajeto para a escola como inseguro (OR = 0,66) reduzem as chances de adoção a tal comportamento. Osresul-tados reforçam a característica multifatorial do deslocamento ativo, e a necessidade de intervenções centradas no sujeito e no ambiente

The purpose of this study is to describe the prevalence of active commuting among Brazilian adolescents in their route home-school by federal units and country regions, and to determine the predictors related to it. Sample comprised 99,967 adolescents (both sexes, mean age 14.24 years) that had taken part in the Bra-zilian National Adolescent School-based Health Survey in 2015. For the present study, it was considered information related to active commuting home-school (frequency and duration), socioeconomic status, and security perception at home-school route, which were obtained through questionnaire. Statistical analysis was performed by logistic regression. It was observed that 44.4% of adolescents reported to use the active commuting (go to and from school using bicycle or walking for, at least, five days a week), and the Southwest region showed the highest prevalence of adolescents who use the active commuting (46.4%). Boys (OR = 1.19), younger adolescents (OR = 0.89), and those who spent more weekly time in active commuting (OR = 1.01) are more prone to be adopt the active commuting in their route to and from school; on the other hand, having a car at home (OR = 0.72) and perceive the route to/from school as insecure (OR = 0.66) decrease their chances to adopt this behaviour. Results highlight that active commuting is a multifactorial trait, and the relevance to develop intervention strategies that should take into account both, subjects and the environment

Physical activity, TV viewing, and human development index in Brazilian adolescents: Results from the National School Health Survey

Abstract Aim: This study aimed to examine the association between physical activity (PA) indicators and TV viewing as a function of the Human Development Index (HDI). Method: This cross-sectional study was based on data from the National School Health Survey, which was composed of 102,072 students (14.28±1.03; 51.3% girls). Total PA, active commuting to school (ACS) and TV viewing were assessed by questionnaires and classified through a gradual scale ranging from "F" (low) to "A+" (high). The correlation between total PA, ACS, TV viewing and HDI was verified by Spearman's Correlation and presented in rs. Results: HDI was positively associated with total PA [girls: rs = 0.572 (p < 0.001); boys: rs = 0.843 (p < 0.001)] and ACS [girls: rs = 0.433 (p < 0.001); boys: rs = 0.554 (p < 0.001)]; while a negative correlation was found between HDI and TV viewing [girls: rs = -0.330 (p < 0.001); boys: rs = -0.348 (p < 0.001)]. Conclusions: Brazilian adolescents from states with higher HDI were more active and spent more time watching TV than their counterparts from states with lower HDI.

Is there any difference between "amateur" and "recreational" runners? A latent class analysis

Abstract Aims: to identify and describe the clustering of characteristics related to running amongst Brazilian runners using latent class analysis and to verify if there is a profile associated with better performance. Material and Methods: a sample of 1149 Brazilian runners answered an online questionnaire, that provided information about biological (sex, age, height, weight), training (running pace, frequency and volume/week, motivation), and socioeconomic factors, as well as a multidimensional questionnaire of fear of failure. Latent Class Analysis was used to identify subgroups of Brazilian runners, based on BMI, training volume and frequency/week, motivation, socioeconomic factors, and the fear of failure. Further, a χ2 test was computed to verify statistical differences in the frequency of the descriptive variables between classes. Finally, binary logistic regression analysis estimated factors associated with running performance, with running pace as the dependent variable. Results: It was possible to identify two different classes among Brazilian runners, which were called "amateur runners" and "recreational runners". Variables that highlighted classes' differences were: volume and frequency training/week, motivation for the practice, and BMI. Regarding the running performance, logistic regression analysis showed that men (OR=5.39; 95%CI=4.00-7.25), young runners (OR=0.38; 95%CI=0.28-0.51), and "amateur runners" (OR=4.19; 95%CI=2.95-5.94) were more prone to have higher performance. Conclusion: Two distinct classes were found among Brazilian runners that were linked to their performance, highlighting that even among non-professional runners, differences can be observed regarding their classification. Hence, future studies should consider using these classes to properly stratify or identify non-professional runners.

Who are the Brazilian adolescents most actives during commuting to school? a population-based study

Abstract Aims: 1) to identify the prevalence of active commuting to school (ACS) among Brazilian regions; and 2) to determine associated factors related to ACS in this population. Methods: Cross-sectional study comprising 16,493 adolescents (mean age 14.09±2.12 years). The data comes from the National School Health Survey (2015), and the information was collected by a self-reported questionnaire. Logistic regression models were performed to identify correlates of ACS. Results: Adolescents who live in the Southeast are more prone to have ACS compared to those who live in other regions. Do not have motor vehicles been positively associated with ACS [girls: 2.04 (1.72;2.42); boys 1.85(1.63;2.10)]. Those whom self-reported white was less prone to have ACS compared to their peers from other ethnicities. Those enrolled in private schools [girls: 0.43(0.34;0.54); boys (0.45(0.39;0.53)] and schools setting in rural area [girls: 0.38(0.25;0.57); boys: 0.51(0.37;71)] are less prone to show ACS. In addition, adolescents who accumulated less active time during physical education classes [girls: 0.80(0.66;0.97)] and extracurricular shifts [boys: 0.69(0.60;0.80)] were less prone to have an ACS, compared to their most active peers. Lastly, girls who spent ≤ 2 hours presented fewer odds to have an ACS [0.75(0.63;0.90)]. Conclusions: ACS was most prevalent among those who live in the Southeast region and seems to be negativity associated with the socioeconomic level. Moreover, less active adolescents during both school and leisure time may be more prone to have passive travel go/from school.

Birth weight, physical growth and body composition in children: A longitudinal study / Peso ao nascer, crescimento físico e composição corporal de crianças: um estudo longitudinal

ABSTRACT Objective To describe children's physical growth (body mass and height) velocity and body composition (fat percentage and Fat Free Mass); to investigate the magnitude of interindividual differences according to age, gender and birth weight categories, as well as to examine the differences in the average trajectories of children with Low Birth Weight and Normal Weight according to international references. Methods The sample consisted of 534 children (279 boys and 255 girls, 7 to 10 years old) evaluated in the first year of study and followed for 3 years with overlap between the ages of 7 and 9 years. Physical growth and body composition measurements included: height, body mass, fat percentage (%Fat) and Fat Free Mass. Multilevel Modelling was used. Results Birth weight was not associated with physical growth and body composition markers at 7 years old or with the velocity of their changes (p>0.05). There were significant interindividual differences in the trajectories of physical growth (height and body mass; p<0.001) and body composition (%Fat and Fat Free Mass; p<0.001). In plotting on international percentile charts, the trajectories of growth and body composition were within expected values for age and gender, regardless of birth weight. Conclusion There are significant differences in the dynamics of stature growth, body mass and Fat Free Mass, and Low Birth Weight has no influence on this trajectory. In addition, values are within the expected range for age and sex.

RESUMO Objetivo Este artigo teve por objetivo descrever a velocidade do crescimento físico (massa corporal e estatura) e a composição corporal (percentual de gordura e massa isenta de gordura) de crianças; investigar a magnitude das diferenças interindividuais em função da idade, gênero e categoria do peso ao nascer; e examinar a diferenciação das trajetórias médias das crianças com Baixo Peso ao Nascer e com Peso Adequado ao Nascer, relativamente às referências internacionais. Métodos A amostra foi composta por 534 crianças (279 meninos e 255 meninas, na faixa etária entre 7 e 10 anos de idade), avaliadas no primeiro ano de estudo e seguidas por três anos, com sobreposição de idade entre 7 e 9 anos. Foram medidas a estatura e a massa corporal, e estimados o percentual de gordura (%Gord) e a Massa Isenta de Gordura. As análises foram realizadas com a Modelagem Multinível. Resultados O peso ao nascer não apresentou associação com as variáveis de crescimento físico e composição corporal aos 7 anos de idade, bem como com seus incrementos dos 7 aos 10 anos (p>0,05). Há diferenças interindividuais significativas nas trajetórias de crescimento físico (estatura, massa corporal; p<0,001) e composição corporal (%Gord e Massa Isenta de Gordura; p<0,001). Na plotagem realizada em cartas percentílicas internacionais, independentemente do peso ao nascer, as trajetórias do crescimento e composição corporal encontram-se dentro dos valores esperados para idade e gênero. Conclusão O estudo concluiu que existem diferenças significativas no dinamismo do crescimento estatural, massa corporal e Massa Isenta de Gordura, e o Baixo Peso ao Nascer não exerce nenhuma influência nessa trajetória. Ademais, os seus valores estão dentro do expectável para idade e gênero.

A cross-cultural study of physical activity and sedentariness in youth from Mozambique and Portugal

Abstract Aim: The purpose of this study was to analyse the effects of age, sex, body mass index (BMI) and country of origin (Mozambique versus Portugal) on physical activity and sedentariness. Methods: Sample size was comprised of 593 adolescents from Mozambique (n=258) and Portugal (n=335), aged 10-15 years old. Height and weight were measured, and BMI was computed; furthermore, subjects were classified in two groups (normal weight and overweight/obese). The mean time (min/day) spent in moderate-to-vigorous physical activity (MVPA), light physical activity (LPA), and sedentary activity were assessed using the GT3X Actigraph accelerometer over at least 4 days (1 weekend day) with a minimum of 10 hours/day of monitoring. Multiple regression analysis was done in SPSS 20. Results: A low percentage of Mozambican (3.9%) and Portuguese (4.3%) youth complied with the MVPA recommendations (60min·day-1). However, Portuguese boys spend more time in MVPA. Girls and those with higher BMI spend more time in sedentary activities and less time in MVPA and LPA; older adolescents spend more time in sedentary activities and less time in LPA. There is a significant effect of the country of origin on MVPA, favouring Portuguese youth. Conclusions: Results suggest country differences in MVPA between Mozambican and Portuguese youth - the Mozambicans are less involved in MVPA than the Portuguese, probably reinforcing the undesirable effect of the urbanization process in developing nations.

Physical activity, BMI and metabolic risk in Portuguese adolescents / Atividade física, IMC e risco metabólico em adolescentes portugueses

Abstract It has been reported, in the last decades, a significant decrease in physical activity (PA) levels, with a consequent increase in obesity and metabolic risk factors among youth. The aims of this study were to describe PA levels, the prevalence of overweight/ obesity and metabolic risk factors, and to examine the association between PA and body mass index (BMI) with metabolic risk among Portuguese youth. The sample comprises 212 Portuguese adolescents (12-16 years old). Height and weight were measured. PA was estimated with the Bouchard questionnaire (3 days recall), as well as with the use of a pedometer (used for 5 consecutive days). Metabolic risk factors comprised fasting glucose, triglycerides, HDL-cholesterol, systolic blood pressure and waist circumference. Subjects were classified as normal weight, overweight or obese according to BMI; the maturational status was indirectly estimated with the maturity offset procedure. A continuous metabolic risk score was computed (zMR) and PA values were divided into tertiles. Quisquare test, t-test and ANOVA were used in statistical analyses. SPSS 18.0 and WinPepi softwares were used and p<0.05. A moderate to high prevalence of overweight/obesity and HDL-cholesterol was found, as well as a high prevalence of high blood pressure and low to moderate PA levels among Portuguese youth. The relationship between BMI and zMR showed that obese adolescents have higher zMR when compared to normal weight or overweight adolescents. This finding suggests that increased levels of PA and reduction in the prevalence of overweight/obesity may have a positive role against the development of metabolic risk factors.

Resumo Tem-se verificado, nas últimas décadas, uma redução substancial nos níveis de atividade física (AF), com o consequente aumento da prevalência de sobrepeso/obesidade e fatores de risco metabólico entre jovens. O presente estudo teve por objetivos identificar os níveis de AF e as prevalências de sobrepeso/obesidade e risco metabólico, e associar o índice ponderal com os níveis de AF e risco metabólico em jovens portugueses. A amostra foi composta por 212 jovens portugueses (12-16 anos). Estatura e peso foram mensurados. AF foi estimada a partir do recordatório de 3 dias de Bouchard e pelo uso do pedômetro (durante 5 dias). Os indicadores de risco metabólico considerados foram: glicose, triglicerídeos, HDL-colesterol, tensão arterial sistólica e perímetro da cintura. Os sujeitos foram classificados consoante índice ponderal a partir do índice de massa corporal, enquanto que o estatuto maturacional foi estimado a partir do offset maturacional. Score contínuo de risco metabólico (zRM) foi calculado, e a AF foi dividida em tercis. Os testes estatísticos utilizados foram o Qui-quadrado, teste t independente e ANOVA, as análises foram conduzidas no SPSS 18.0 e WinPepi (p<0,05). Observou-se uma prevalência moderada a elevada de sobrepeso/obesidade e HDL-colesterol, uma elevada prevalência de risco para tensão arterial, e níveis de AF baixos a moderados entre jovens portugueses. A relação entre índice ponderal e zRM mostrou que adolescentes obesos apresentam maior zRM comparativamente aos adolescentes normoponderais ou com sobrepeso. Incrementos nos níveis de AF e redução da prevalência de sobrepeso/obesidade podem ter um papel relevante na redução de fatores de risco metabólico.

Modelação multinível e delineamento longitudinal-misto na pesquisa em Educação Física e Ciências do Esporte / Multilevel modeling and mixed longitudinal design in the research in Physical Education and Sport Medicine

O propósito deste estudo é apresentar o uso da modelação multinível (MMN) com informação oriunda de um estudo longitudinal-misto sobre o crescimento, desenvolvimento e saúde de adolescentes portugueses. A amostra foi composta por 5155 indivíduos divididos em quatro coortes que abrangem as faixas etárias dos 10 aos 12, 12 aos 14, 14 aos 16 e 16 aos 18 anos. As variáveis de estudo foram a força de preensão manual e o percentual de gordura total (%GTotal). A análise mostrou trajetórias curvilíneas do desempenho de força de preensão, com maiores incrementos anuais nos meninos. O %GTtotal apresentou associação positiva com o desempenho da força estática; constatou-se uma forte variabilidade interindividual. O recurso ao delineamento longitudinal-misto permitiu a recolha mais célere da informação; e a metodologia MMN mostrou-se suficientemente flexível e robusta para acomodar, num modelo único, aspectos da mudança individual e das diferenças interindividuais do desempenho da força estática condicionados à ação do tempo.

The main aim of this study was to introduce the use of multilevel modeling in the data from a mixed longitudinal study concerning growth, development and health of Portuguese adolescents. The sample comprises 5155 subjects from 4 age cohorts: 10 to 12, 12 to 14, 14 to 16 and 16 to 18 years. Variables chosen for analysis were handgrip strength and percentage of total body fat. Multilevel modeling analysis showed a quadratic trajectory of adolescents' handgrip strength performance, with higher annual increasing in boys. The percentage of total body fat was positively associated with the static strength and there were marked interindividual differences. The use of a mixed longitudinal design allowed a faster data collection process; in addition, multilevel modeling analysis was sufficiently flexible and robust to accommodate, in a single model, aspects of individual and interindividual changes in static strength development over the time.

Associação entre atividade física, aptidão cardiorrespiratória e síndrome metabólica em crianças e adolescentes: estado da arte / Association between physical activity, cardiorespiratory fitness and metabolic syndrome in youth: the state of the art

O presente estudo teve como objetivo sintetizar os principais resultados da associação entre atividade física (AF) e/ou aptidão cardiorrespiratória com a síndrome metabólica (SM) em crianças e adolescentes. Efetuou-se uma busca on-line nas bases de dados Pubmed, Scopus, Web of Science e Lilacs para selecionar artigos que investigaram a relação entre AF e/ou aptidão cardiorrespiratória e SM em crianças e adolescentes, publicados entre os anos de 2004 e 2009. Foram localizados 20 estudos que atenderam aos critérios adotados, dos quais 19 compuseram a amostra. Uma associação negativa entre AF e/ou aptidão cardiorrespiratória e SM foi observada. Os valores da associação apresentaram oscilação, a qual pode ser relacionada aos métodos utilizados para recolha da informação, à inexistência de critérios unânimes para determinação da SM em crianças e adolescentes, ao tamanho e características amostrais. Os resultados sugerem que incrementos dos níveis de AF (odds ratio de 1,3 a 5,16, e b = -0.02 a -0.21) e aptidão cardiorrespiratória (odds ratio de 2,42 a 13,0, e b = -0.09 a -0,44) em jovens se apresentam como estratégias para prevenção de fatores de risco metabólico. Não obstante a representatividade dos dados, há a necessidade de estudos posteriores em populações de nações em transição, de forma a possibilitar uma melhor compreensão desta relação.

The present study aimed to summarize the main results of the association between physical activity (PA) and cardiorespiratory fitness with metabolic syndrome (MS) in children and adolescents. An on-line search was made on Pubmed, Scopus, Web of Science and Lilacs databases for published studies concerning the relationship between PA and/or cardiorespiratory fitness with MS in children and adolescents. Published studies covered a period from 2004 to 2009. Twenty studies were found showing according to inclusion criteria, but only 19 were included in the sample. In general a negative association between PA and cadiorespiratory fitness with MS was observed. The association was not equal across studies; a wide variability between them was found, and design of each study, sample size and characteristics, as well as the lack of a universal definition of MS in youth may account for such discrepancies. Improvement on PA levels (odds ratio between 1,3 to 5,16, and b = -0.02 to -0.21) and on cardiorespiratory fitness (odds ratio between 2,42 to 13,0, and b = -0.09 to -0,44) in youth is a potential strategy to overcoming the metabolic risk factors in this population. Notwithstanding data representativeness, it is necessary further studies in developing countries population for a better understanding for this relationship.