João Otacilio Libardoni dos Santos

Obesity and Overweight Among Brazilian Early Adolescents: Variability Across Region, Socioeconomic Status, and Gender

Introduction As with most emerging nations, Brazil lacks up-to-date data on the prevalence of obesity and overweight among its children. Of particular concern is the lack of data on children in early adolescence, considered by many to be the crucial stage for weight-related healthcare. Objective To assess regional, socioeconomic, and gender differences in the prevalence of obesity and overweight among Brazilian early adolescents. Methods A cross-sectional study was conducted on a racially diverse sample of students aged 10–13 years, from schools in three geographic regions (north, northeast, south) (N = 1,738). Data on gender, age, race, socioeconomic status (SES), weight, and height were obtained. Weight class was calculated from age- and gender-adjusted body mass index, based on children’s weight and height. Bivariate and multivariable analyses, with post hoc tests, were conducted to estimate differences between groups and were corrected for multiple comparisons. Procedures were approved by institutional review boards at study sites. Results Analyses revealed a higher prevalence of obesity and/or overweight among: (1) children of higher SES; (2) children in southern Brazil; (3) males; and (4) Black females. Conclusion The most salient predictor of weight risk among Brazilian early adolescents is higher SES. This finding is consistent with previous findings of an inverse social gradient, in weight risk, among emerging-nation population groups.

Functional resistance training can increase strength, knee torque ratio, and functional performance in elderly women

Functional resistance training can increase strength, knee torque ratio, and functional performance in elderly women. The aim of the present study was to understand the effects of closed kinetic chain exercises with constant load on muscular strength, the knee torque conventional ratio (hamstring:quadriceps – H:Q), and functional capacity in the elderly. Nine untrained healthy elderly women participated in experimental resistance training. Ten-repetition maximum (10RM) for the deadlift, isokinetic maximum voluntary concentric contraction, and functional capacity were assessed before and after the 7-week resistance-training program. Magnitude based inference analysis was used to examine the differences in muscle strength and functional performance. Therefore, the smallest worthwhile change was calculated and 90% confidence intervals were also determined to characterize muscle strength and functional performance. The analysis demonstrated an increase in the deadlift and knee flexor torque (60o/sec) after the experimental intervention. Furthermore, stair ascent, knee extensor torque (120o/sec), knee flexor torque (120o/sec), and knee ratio (60o/sec) also presented a positive effect in the same training period. Conversely, knee extensor torque (60o/sec), and knee ratio (120o/sec) did not show conclusive responses. In conclusion, resistance training with functional closed kinetic chain exercises and constant volume load (i.e., 65% of 1-repetition maximum) can increase deadlift 10RM, isokinetic concentric torque, the conventional H:Q ratio, and stair ascent performance in elderly women.

Factorial Structure Validation of the Movement Assessment Battery for Children in School-Age Children Between 8 and 10 Years Old

espanolResumen: La adaptacion de instrumentos para otros contextos culturales es una tarea compleja que requiere rigor para mantener el contenido y las caracteristicas psicometricas. Una de las herramientas de evaluacion motora mas utilizada en el mundo es el Movement Assessment Battery for Children 2ed. En este estudio se evaluo, desde el punto de vista de la teoria de la psicometrica clasica y moderna, la organizacion factor del MABC-2 para el grupo de edad de 8-10 anos. Para eso, fueron evaluados 350 estudiantes de la ciudad de Manaus (AM, Brazil). La estructura factorial original del MABC-2 con tres factores y tambien nueva estructura factorial del MABC-2(4 factores) se pusieron a prueba. Para el analisis de datos se utilizo la estadistica descriptiva e inferencial. El analisis factorial confirmo el modelo original de tres factores. Con base en estos resultados se pudo identificar buenas evidencias de validez basada en la estructura interna del MABC-2 propuesta por los autores originales, que confirman su capacidad para identificar trastornos en el desarrollo de la coordinacion. EnglishAbstract: The adaptation of instruments to other cultural contexts is a complex task that requires careful planning to maintain the content and psychometric properties. One of the most used motor assessment tools in the world is the Movement Assessment Battery for Children 2ed. In this study, we evaluated the factorial organization of the MABC-2 for the age group 8-10 years from the perspective of classical and modern psychometric theory. For this purpose, a group of 350 school children in the city of Manaus (AM, Brazil) was evaluated. The factorial structure of the MABC-2 and a new factorial structure with four factors were tested. For data analysis, descriptive and inferential statistics were used. Factor analysis confirmed the original three-factor model. Based on these results, good evidences of validity were produced, based on the internal structure of the MABC-2 proposed by the original authors, confirming its ability to identify disorders in the development of coordination. portuguesResumo A adaptacao de instrumentos para outros contextos culturais e uma tarefa complexa, que exige rigor quanto a manutencao do conteudo e das caracteristicas psicometricas. Um dos instrumentos de avaliacao motora mais utilizados no mundo trata-se do Movement Assessment Battery for Children 2ed. Neste estudo avaliou-se a partir da perspectiva da teoria da psicometrica classica e moderna, a organizacao fatorial do MABC-2 para a faixa etaria de 8 a 10 anos. Para isso foram avaliados 350 escolares da cidade de Manaus (AM, Brazil) Foram testadas a estrutura fatorial original do MABC-2 composta por tres fatores e ainda uma nova estrutura fatorial do MABC-2 (4 fatores). Para analise dos dados foi utilizada a estatistica descritiva e inferencial. A analise fatorial confirmou o modelo original de tres fatores. Com base nestes resultados foi possivel identificar boas evidencias de validade baseada na estrutura interna do MABC-2 proposto pelos autores originais confirmando a sua capacidade de identificar desordens no desenvolvimento da coordenacao.

The influence of gender on the practice of physical activity in high school adolescents in the city of Manaus

A obesidade é um problema de saúde pública que cresce especialmente em países em desenvolvimento, estando associado tanto a fatores genéticos quanto a fatores culturais como o excesso de alimentação associados a elevados níveis de sedentarismo. O objetivo deste estudo foi comparar os comportamentos sedentários e níveis de atividade física, em função do gênero, nos adolescentes do ensino médio na rede pública estadual da cidade de Manaus, Brasil. Participaram do estudo 864 adolescentes de ambos os gêneros com idade entre 15 e 19 anos. As informações foram coletadas por meio de questionário formulado e adaptado com base no COMPAC2. Os resultados foram apresentados utilizando a estatística descritiva e a comparação entre os grupos (masculino e feminino) foi realizada por meio do teste Qui-quadrado. O grupo de alunos do sexo masculino (M) apresentou maior participação nas práticas físicas e mostrou maior tempo de dedicação nessas atividades do que o grupo feminino (F), já que este último declarou preferência ao uso do computador e à participação em atividades culturais. Além disso, 64,3% dos rapazes e 35,5% das moças declararam dedicar entre 30 e 60 minutos ou mais por dia para a prática de atividade física. A forma mais usada de deslocamento até a escola foi a pé (M: 62,3%; F: 57,8%). Em relação aos comportamentos sedentários 60% dos avaliados afirmaram passar mais de 2 horas assistindo programas de televisão e 52% dos rapazes e 42,8% das moças declararam usar o computador por mais de 2 horas diárias. Os resultados revelaram que as estudantes do sexo feminino praticam menos atividades físicas que os estudantes do sexo masculino.