Patterns of physical performance spurts during adolescence: a cross-cultural study of Canadian, Brazilian and Portuguese boys.

BACKGROUND: Data relating physical performance to the timing of the adolescent growth spurt are limited. Aim: This study identifies: (i) age-at-peak height velocity (APHV), (ii) physical performance spurt patterns aligned to APHV; and (iii) cross-cultural and time patterns in Canadian, Brazilian and Portuguese boys. Subjects and methods: A total of 512 boys (131 Canadian, 250 Portuguese and 131 Brazilian), 8-17 years of age were followed serially using longitudinal data. APHV was identified and five physical performance measures velocities [trunk extension (TE), trunk flexion (TF), standing long jump (SLJ), curl-ups (CU) and handgrip strength (HG)] were aligned at 6-month intervals, 4 years around the attainment of PHV. Velocities were estimated using a non-smooth mathematical procedure. Results: APHV was 13.9 ± 1.0, 13.4 ± 1.6 and 13.0 ± 0.8 years for Canadian, Brazilian and Portuguese boys, respectively. Maximal velocity in SLJ was attained between 12 and 6 months prior to PHV. For HG, peaks were attained 12-24 months after PHV. Maximal velocity in TE occurred between 12 and 0 months prior to PHV, while CU peaked between PHV and 6 months after PHV. Conclusion: Patterns of spurts in physical performance have remained relatively the same and do not appear to be influenced by cross-cultural differences.

Development of Physical Performance Tasks during Rapid Growth in Brazilian Children: The Cariri Healthy Growth Study.

Growth and physical performance scores were studied around three years of attainment of peak height velocity (PHV). We aimed to estimate the age at peak velocity, or at peak rate, in physical performance tasks, and sex-differences when aligned by biological age. A total of 131 boys and 123 girls, 8 to 14 years of age were recruited from the Cariri region of Brazil. A mixed longitudinal design was used with four overlapping age cohorts: 8, 10, 12, and 14 years, followed for three years, with measurements performed at 6 month intervals. Height, 12 min run (12mR), handgrip strength (HG), standing long jump (SLJ), and shuttle run (SR) velocities were estimated using a non-smooth mathematical procedure. Age at PHV was 13.4 ± 1.6 years in boys compared with 12.2 ± 2.3 years in girls. Maximal velocity in SLJ was attained 6 and 3 months prior to PHV in boys and girls, respectively. For HG, peaks were attained 9 months after PHV in boys and 15 months after PHV in girls. Maximal velocity in 12mR was attained 6 months before PHV in boys and at PHV in girls, whereas a peak in SR occurred 12 months after PHV in both sexes. In conclusion, dynamic changes in physical performance relative to PHV appear similar in both sexes, although sex differences were evident in some motor tests.

An Allometric Modelling Approach to Identify the Optimal Body Shape Associated with, and Differences between Brazilian and Peruvian Youth Motor Performance.

Children from developed and developing countries differ in their body size and shape due to marked differences across their life history caused by social, economic and cultural differences which are also linked to their motor performance (MP). We used allometric models to identify size/shape characteristics associated with MP tests between Brazilian and Peruvian schoolchildren. A total of 4,560 subjects, 2,385 girls and 2,175 boys aged 9-15 years were studied. Height and weight were measured; biological maturation was estimated with the maturity offset technique; MP measures included the 12 minute run (12MR), handgrip strength (HG), standing long jump (SLJ) and the shuttle run speed (SR) tests; physical activity (PA) was assessed using the Baecke questionnaire. A multiplicative allometric model was adopted to adjust for body size differences across countries. Reciprocal ponderal index (RPI) was found to be the most suitable body shape indicator associated with the 12MR, SLJ, HG and SR performance. A positive maturation offset parameter was also associated with a better performance in SLJ, HG and SR tests. Sex differences were found in all motor tests. Brazilian youth showed better scores in MP than their Peruvian peers, even when controlling for their body size differences The current study identified the key body size associated with four body mass-dependent MP tests. Biological maturation and PA were associated with strength and motor performance. Sex differences were found in all motor tests, as well as across countries favoring Brazilian children even when accounting for their body size/shape differences.

Fat Mass Centile Charts for Brazilian Children and Adolescents and the Identification of the Roles of Socioeconomic Status and Physical Fitness on Fat Mass Development.

This paper presents fat mass centile charts for Brazilian youth and investigates the roles of socioeconomic status and physical fitness (PF) on fat mass (FM) development. Two northeast Brazilian samples were used: a cross-sectional sample of 3659 (1921 girls) aged 8 to 16 years and a mixed-longitudinal series of cohorts (8-10, 10-12, 12-14, 14-16 years) with 250 boys and 250 girls. A measure of somatic maturity was used as a marker of biological maturation; PF comprised agility, explosive and static strength, and aerobic capacity. Socioeconomic status was based on school attended; public or private. Slaughter's anthropometric equations were used to estimate FM. Percentile charts was constructed using the LMS method. HLM (Hierarchical Linear Model) 7 software modeled FM changes, identifying inter-individual differences and their covariates. Girls and boys had different FM percentile values at each age; FM increased nonlinearly in both girls and boys. Higher PF levels reduced FM changes across time in both sexes. Sex-specific non-linear FM references were provided representing important tools for nutritionists, pediatriciann and educators. Physical fitness levels were found to act as a protective factor in FM increases. As such, we emphasize PF importance as a putative health marker and highlight the need for its systematic development across the school years.

Estudos longitudinais sobre o crescimento somático e desempenho motor: delineamentos, desafios, necessidades / Longitudinal studies on somatic growth and motor performance: designs, challenges, and needs

O objetivo principal desta revisão é fornecer uma visão geral dos principais estudos longitudinais e longitudinais-mistos que se centraram sobre o crescimento somático, maturação biológica e, mais recentemente, também no desempenho físico. Somente foram considerados os estudos realizados na América do Norte, Europa e países de língua portuguesa. Em primeiro lugar, são apresentadas as principais considerações teóricas, características gerais, o delineamento do estudo e análise estatística multivariada dos dados. Na segunda parte, é edificado o panorama geral sobre os estudos emblemáticos de natureza longitudinal e longitudinal-mista. Finalmente, foram considerados alguns dos principais desafios que se colocam à pesquisa longitudinal.

The main objective of the present review of the literature was to provide an overview of the major longitudinal and mixed longitudinal studies focusing on somatic growth, biological maturation, and, more recently, physical performance. We selected studies conducted in the USA, Europe, and Portuguese speaking countries. First, the main theoretical considerations, general characteristics, study designs, statistical analyses, and methodological challenges of the data were presented. Next, we provided an overview of the most important longitudinal and mixed longitudinal studies. Finally, the major challenges of the ongoing studies were outlined.

Short-term tracking of performance and health-related physical fitness in girls: the Healthy Growth in Cariri Study.

The main purpose of this study was to track the performance and health-related physical fitness of girls from Brazil's Cariri region. In the "Healthy Growth in Cariri Study", 294 girls from public and private schools were divided into four age cohorts--8, 10, 12, and 14 years--and followed for three consecutive years, with an assessment every 6 months. Shuttle run, hand grip, standing long jump, trunk lift, curl-up, 12-min run, and fatness were used to rate physical fitness performance and health-related components on each of six occasions. Tracking was done in a stepwise manner, using auto-correlation, by modelling the individual history of change in performance of each girl, and using Foulkes and Davies' γ-coefficient. SPSS 18.0 and TIMEPATH were used for data analysis. Auto-correlations evidenced low-to-moderate values in almost all components of performance and health-related physical fitness. Intra-individual tracking analysis showed large variation in all fitness components as a result of a wide spread in individual history of change in fitness performance. Population estimates of γ were low in all tests. Our results show low-to-moderate tracking of physical fitness components of girls. A wide range of intra-individual and inter-variability in fitness development was observed.

Growth references for Brazilian children and adolescents: healthy growth in Cariri study.

AIM: To construct reference values for height, body mass and BMI of children and adolescents from the Cariri region, Brazil; to compare the growth of Cariri children with those from CDC (Centers for Disease Control and Prevention) and with references from other Brazilian regions; to verify the associations between socioeconomic status and height, body mass and BMI in children and youth from both sexes. SUBJECTS AND METHODS: The sample comprised 3311 girls and 3280 boys aged 7-17 years, participating in the study 'Healthy Growth in Cariri'. Socioeconomic status was defined according to school attendance: private and public. Centile curves for height, body mass and BMI were constructed using the LMS method. RESULTS: Significant differences between children and adolescents from Cariri and those from other Brazilian regions and the CDC references were found for height and body mass. In girls from private schools, average differences in height compared to the CDC references ranged from 0.79-5.9 cm and in boys from 2.9-8.6 cm. CONCLUSION: Children from Cariri show a growth pattern in height, body mass and BMI that closely resembles the patterns observed in developed countries, but the absolute values in height and body mass are markedly lower than CDC references and growth references for other regions in Brazil.

Valores normativos do desempenho motor de crianças e adolescentes: o estudo longitudinal-misto do Cariri / References values of motor development in children and adolescents: a mixed-longitudinal study of Cariri

Este estudo teve como objetivos: 1) apresentar cartas percentílicas e valores de referência para um conjunto variado de testes motores; e 2) comparar o desempenho das crianças e jovens cearenses com o de outros estudos desenvolvidos noutras regiões do país e do exterior. A amostra total é composta por 6.238 indivíduos (3.122 meninas e 3.116 meninos) com idades compreendidas entre os oito e os 17 anos. As cartas percentílicas foram construídas separadamente para cada sexo utilizando o método LMS implementado no "software" LMSchartmaker Pro versão 2.3. As cartas de referência produzidas para o Cariri apresentam um comportamento genérico semelhante ao verificado nos estudos considerados. Com exceção da prova do "trunk lift", constata-se uma nítida superioridade do desempenho dos meninos, enfatizando a presença de forte dimorfismo sexual. A comparação dos valores do P50 de crianças e jovens do Cariri relativamente às de Londrina (Brasil) e de Portugal mostraram performances consistentemente inferiores.

The aim of this study was: 1) to provide centile charts and reference values for a variety of motor tests and; 2) to compare the performance of children and adolescents from the Cariri-region with other national and international reference data. The total sample consists of 6.238 individuals (3.122 girls and 3.116 boys) between 8 and 17 years. The centile charts were constructed for each sex separately using the LMS method implemented in the LMSchartmaker Pro version 2.3. The reference charts of Cariri-region are similar to that observed in previously reported studies. Except for trunk lift boys outperform girls at most age levels, emphasizing the presence of sexual dimorphism. The P50 values of children and adolescents from Cariri were consistently lower than the P50-values of children and adolescents from Londrina (Brazil) and other samples from Portugal.

Aptidão cardiorespiratória e composição corporal em crianças e adolescentes / Cardiorespiratory fitness and body composition in children and adolescents

O presente estudo teve por objetivo avaliar o nível de aptidão cardiorrespiratória e de composição corporal em crianças e adolescentes caririenses. A amostra é constituída de 461 indivíduos (230 do sexo masculino e 231 feminino) com idades entre e 8 e 16 anos, oriundas de escolas públicas e privadas da região do cariri cearense. As crianças foram submetidas à análise da composição corporal com base na avaliação de peso e a estatura e das dobras cutâneas. A resistência cardiorrespiratória foi avaliada através do teste de corrida/caminhada por 12 minutos. Os resultados demonstraram que as meninas e os meninos começam a apresentar diferenças importantes nas variáveis de composição corporal a partir da coorte 3 para as meninas e do coorte 4 para os meninos, onde está presente o período pubertário. Em relação à aptidão cardiorespiratória, observa-se que os meninos em todas as coortes possuem uma aptidão quando comparado às meninas.

This study aimed to assess the level of cardiorespiratory fitness and body composition in children and adolescents from cariri region. The sample consists of 461 individuals (230 male and 231 female) aged between 8 and 16 years old, from public and private schools in the region of Cariri-Ceará-Brazil. The children were evaluated of body composition based on the assessment the weight and height, triceps and subscapular skinfolds. The endurance was evaluated through the test for 12 minutes. Through these results, we can conclude that girls and boys start to make important differences in body composition variables in the group 3 for girls and 4 for boys, this is where the pubertal period. For cardio respiratory fitness the boys in all cohorts have a better fitness than girls.

Maturação biológica: da sua relevância à aprendizagem do método TW3 / The relevance of training in the TW3 method for the evaluation of biological maturation

Este estudo teve os seguintes objetivos: (1) apresentar procedimentos metodológicos utilizados na estimação da idade óssea; (2) descrever o método Tanner-Whitehouse (TW3), e (3) destacar os resultados da reprodutibilidade deste método em crianças e jovens. A metodologia adotada na preparação do processo de aprendizagem e reprodutibilidade do método TW3 foi estruturada em três fases, tendo sido realizadas em duas Instituições de ensino (Portugal e Bélgica), sob a orientação e supervisão de avaliadores experientes. Após várias etapas de treinamento, os resultados alcançados na avaliação inter e intraobservador situaram-se entre 81,3 e 87,9%. Os resultados finais do estudo possibilitaram comprovar a eficácia de um rigoroso processo de treino, como elemento essencial na preparação prévia do avaliador, para a utilização da avaliação da maturação esquelética com base no método TW3.

The objectives of this study were: (1) to present methodological procedures used for the estimation of bone age; (2) describe the Tanner-Whitehouse method (TW3), and (3) to highlight the results of reproducibility of this method in children and adolescents. The method adopted for the preparation of the learning process and for evaluation of the reproducibility of the TW3 method was divided into three phases and was conducted at two teaching institutions (Portugal and Belgium) under the guidance and supervision of experienced raters. After severalstages of training in the rating of radiographs, inter- and intraobserver reliability ranged from 81.3 to 87.9%. The final results of the study demonstrate the effectiveness of a rigorous training process as an essential element in the previous preparation of raters for the assessment of skeletal maturation by the TW3 method.

Análise e interpretação dos níveis de actividade física de crianças: um tutorial baseado na modelação hierárquica ou multinível / Analysis and interpretation of physical activity levels in children: a tutorial based on hierarchical or multilevel modelling

Este tutorial pretende apresentar, de modo didáctico, uma forma alternativa de análise de dados sobre os níveisde actividade física de crianças a partir da modelação hierárquica ou multinível. São mencionadas as diferentes etapas damodelação, os resultados são interpretados com base nos output´s do software utilizado - o HLM 6.02. Em cada etapa do percurso são lançadas as hipóteses mais importantes em grau de complexidade crescente. A sua importância é referida a partir dos resultados disponíveis...

This tutorial aims at a didactical presentation of an alternative approach to analyse physical activity data of children based on hierarchical or multilevel modelling. We present the basic steps of the data analysis, interpreting all relevant outputfrom the chosen software - HLM 6.02. Each step is duly presented and explained, going from simple hypothesis to more complex ones. Their relevancy is presented in terms of the available results...

Semelhança somatotipológica entre irmãos / Sibling similarities in somatotype

O presente estudo visou averiguar a semelhança somatotipológica entre irmãos. A amostra foi constituída por 366 pares de irmãos de ambos os sexos com idades compreendidas entre os 10 e os 18 anos. Foram efectuadas medições de altura; peso; três pregas de adiposidade subcutânea (tricipital, subescapular e supraíliaca); dois perímetros (braquial e geminal) e dois diâmetros (bicôndilo-umeral e bicôndilo-fémural), sendo o somatótipo calculado de acordo com o procedimento de Heath-Carter. Os procedimentos estatísticos utilizados foram os seguintes: coeficiente de correlação de Pearson e correlação canónica, calculados no software SYSTAT 11.0. Os principais resultados foram: (1) os valores de correlação entre irmãs são superiores na endomorfia (r=0,46) e ectomorfia (r=0,40); (2) os rapazes entre si apresentam maior semelhança na componente ectomórfica (r=0,44);(3) na mesomorfia os valores de correlação são moderados tanto para pares de irmãs como para os pares de irmãos rapazes; (4) nos pares de irmãos de sexo oposto os valores de correlação são muito baixos em qualquer uma das componentes do somatótipo (0,07 a 0,27); (5) de acordo com o conceito tridimensional do somatótipo, os resultados da análise canónica (Rc=0,51) indicam uma semelhança somatotipológica superior nos irmãos dosexo masculino. De uma forma geral, os valores de correlação entre os pares de irmãos sugerem uma semelhança somatotipológica moderada.

The present study aim to analyze the similarity in somatotype. The sample comprised 366 sibling pairs of both sex, with 10 to 18 years of age. Height, weight, triceps, subscapular, upraspinale, and median calf skinfolds,biepcondylar of the humerus and femur, upper arm girth, elbow flexed and tensed, calf girth were measured andsomatotype was calculated according of the Heath-Carter method. Pearson correlation was used to analyze thesibling similarities in each somatotype component. Canonical correlation was used to analyze sibling similaritiesin somatotype as a tridimensional unity, calculated in software SYSTAT 11.0. The main results were: (1) in sistersthe correlations are higher in endomorphy (r=0,46) and ectomorphy (r=0,40); (2) in brothers the highest correlation was in ectomorphy component (r=0,44); (3) in mesomorphy the correlation values are moderate both in brothers and sisters. (4) In sibling pairs of opposite sex, the correlation values are low in all three components (0,07 to 0,27); (5) The results of canonical correlation showed a higher similarity in brothers (Rc=0,51) than in the others sibling pairs. In general the correlation between siblings suggests a moderate similarity in somatotype.

Padrão de actividade física escolares / Pattern of Physical activity of scholarly

O presente estudo teve como principal objectivo inventariar o padrão da actividade física habitual de criança sem contexto escolar. O estudo foi realizado com crianças do 4° ano do ensino básico em duas escolas do Município de Vila Nova de Gaia/Portugal, com uma amostra constituída por 49 crianças de ambos os sexos, comidade média de 10 anos. O instrumento utilizado foi o acelerómetro portátil (Tritrac-R3D), colocado na cintura das crianças durante cinco dias. Os procedimentos estatísticos utilizados foram as medidas descritivas habituais (média, desvio padrão, frequências absolutas e relativas) e o t-teste de medidas independentes. Os principais resultados foram os seguintes: (1) as crianças evidenciaram durante o período escolar um predomínio de actividade física de intensidade baixa, não realizando, no mínimo, 30 minutos de actividade física moderada a vigorosa diária; (2) os meninos apresentaram valores significativamente (p>0.05) mais elevados do que as meninas de actividade física moderada a vigorosa no recreio; (3) as crianças, mesmo em sessões organizadas de Educação Física, apresentaram um padrão de actividade física caracterizado pela sua baixa intensidade, não despendendo pelo menos 50% do tempo total da aula em actividade física moderada a vigorosa; (4) o dispêndio energético não expressou um comportamento diferente nas sessões organizadas de Educação Física e nos momentos de actividade livre de recreio...

The main purpose of the present study was to assess usual physical activity (PA) patterns of school children. The study was carried out with 49 boys and girls (mean age of 10 years) in 4th grade of two schools in Vila Nova de Gaia/Portugal. Children wore a portable accelerometer device (TritracûR3D) on the waist for 5 days. Statistical procedures included descriptives (means, standard deviation, frequency) and independent t-test. The main results were as follows: (1) during the school period, PA level was low, with children not doing the daily minimum of 30 minutes of moderate to vigorous PA; (2) boys showed a higher pattern of moderate to vigorous PAthan girls during recess period; (3) children, even in organized physical education (PE) classes, demonstrated a low PA pattern, with less of 50% of the total PE class time in moderate at vigorous PA; (4) there was no difference in energy expenditure when comparing PE class and school recess...

Classificação morfológica de volibolistas do sexo feminino em escalões de formação / Physique classification of female volleyball players in beginner's class

As características morfológicas têm sido objeto de vários estudos em Ciências Desporto, pelo fato de o fenômeno do desporto de alta competição exigir o máximo da estrutura física dos atletas e pela expectativa da função que o atleta desempenha em jogo. O presente estudo teve como objetivo: (1) descrever e comparar, do ponto de vista somático, a estrutura morfológica de 71 atletas de voleibol do sexo feminino dos escalões de formação A e B (entre os 12 e 14 anos de idade); (2) identificar os componentes da estrutura somática quemelhor diferenciam as atletas de níveis distintos. Para a avaliação da estrutura somática das atletas foram efetuadas 21 avaliações, incluindo além do peso e altura, comprimento dos membros, perímetros, diâmetros e pregas de adiposidade subcutâneas. Com o intuito de verificar o poder discriminatório das variáveis na separação dos grupos, foi utilizada a análise da função discriminante (AFD). Os resultados evidenciaram que não houve diferença quanto à estrutura morfológica entre as atletas dos níveis A e B. Quanto à classificação somatotipológica, as atletas foram classificadas na categoria meso-endomórfica (A = 4.76 - 3.78 - 1.85; B =4.37 - 4.02 - 1.88).

The physique characteristics have been subject of several studies in sport sciences, because the highcompetition sports demand the maximal of physical constitution of the players. Furthermore, the function performedby the players in a game may be related to a particular modality. The mean goals of the present study were: (1). To describe and to compare, from a somatic point of view, the physique of 71 female volleyball players by the level of initiation A and B (aged 12-14 years); and (2) To identify the components of somatic structure that better differentiate the athletics by levels of initiation. To evaluate the players' somatic structure, we perform 21 measures including: weight and height, diameters, circumferences, upper and lower limb measures and skinfolds thickness. Discriminant function analysis (DFA) was used to identify the power of variables classification. No differencewas in physique between level A and B players. They were classified by the somatotype as mesomorphicendomorphs(A = 4.76 - 3.78 - 1.85; and B = 4.37 - 4.02 - 1.88).