Testing Seefeldt's Proficiency Barrier: A Longitudinal Study.

The idea that proficiency in the fundamental movement skills (FMS) is necessary for the development of more complex motor skills (i.e., the proficiency barrier) and to promote health-enhancing physical activity and health-related physical fitness levels is widespread in the literature of motor development. Nonetheless, to the best of our knowledge, there is no study assessing whether children presenting proficiency below a specified proficiency barrier would demonstrate difficulty in improving performance in more complex skills-even when subjected to a period of practice in these complex skills. The present study tested this. Eighty-five normal children (44 boys) aged 7 to 10 years participated in the study. The intervention took place during 10 consecutive classes, once a week, lasting 40 min each. Six FMS (running, hopping, leaping, kicking, catching and stationary dribbling) and one transitional motor skill (TMS) (speed dribbling skill) were assessed. The results showed that only those who showed sufficient proficiency in running and stationary dribbling before the intervention were able to show high performance values in the TMS after intervention. In addition, in line with recent propositions, the results show that the basis for development of the TMS was specific critical components of the FMS and that the barrier can be captured through a logistic function. These results corroborate the proficiency barrier hypothesis and highlight that mastering the critical components of the FMS is a necessary condition for motor development.

Genetic and environmental influences on human height from infancy through adulthood at different levels of parental education.

Genetic factors explain a major proportion of human height variation, but differences in mean stature have also been found between socio-economic categories suggesting a possible effect of environment. By utilizing a classical twin design which allows decomposing the variation of height into genetic and environmental components, we tested the hypothesis that environmental variation in height is greater in offspring of lower educated parents. Twin data from 29 cohorts including 65,978 complete twin pairs with information on height at ages 1 to 69 years and on parental education were pooled allowing the analyses at different ages and in three geographic-cultural regions (Europe, North America and Australia, and East Asia). Parental education mostly showed a positive association with offspring height, with significant associations in mid-childhood and from adolescence onwards. In variance decomposition modeling, the genetic and environmental variance components of height did not show a consistent relation to parental education. A random-effects meta-regression analysis of the aggregate-level data showed a trend towards greater shared environmental variation of height in low parental education families. In conclusion, in our very large dataset from twin cohorts around the globe, these results provide only weak evidence for the study hypothesis.

Familial aggregation and heritability of markers of metabolic risk, physical activity, and physical fitness in nuclear families from Muzambinho (Minas Gerais, Brazil)

ABSTRACT Objective This study investigated the familial aggregation and heritability of markers of metabolic risk, physical activity, and physical fitness in nuclear families from Muzambinho (Minas Gerais, Brazil). Subjects and methods The study included members of 139 families, comprising 97 fathers (aged 40 ± 7 years), 129 mothers (35 ± 6 years), 136 sons (12 ± 4 years), and 121 daughters (12 ± 5 years). Evaluated markers included (A) body mass index, waist circumference, glycemia, and cholesterolemia, as metabolic risk markers; (B) total weekly volume of physical activity, as a physical activity marker; and (C) relative muscle strength, as a physical fitness marker. Correlations between family members and heritability (h2) were estimated using the software S.A.G.E. Results Significant familial correlations were obtained between parents-offspring for glycemia and cholesterolemia (both ρ = 0.21, p < 0.05) and relative muscle strength (ρ = 0.23, p < 0.05), and between siblings for waist circumference, glycemia, total weekly volume of physical activity, and relative muscle strength (ρ variation 0.25 to 0.36, p < 0.05). Heritability values were significant for almost all variables (h2 variations: 20% to 57% for metabolic risk markers, 22% for the total weekly volume of physical activity, and 50% for relative muscle strength), except for waist circumference (h2 = 15%, p = 0.059). Conclusion The presence of significant correlations between family members and/or significant heritability strengthens the possible genetic and/or common familial environment influence on metabolic risk markers, total weekly volume of physical activity, and relative muscle strength.

Familial aggregation and heritability of markers of metabolic risk, physical activity, and physical fitness in nuclear families from Muzambinho (Minas Gerais, Brazil).

OBJECTIVE: This study investigated the familial aggregation and heritability of markers of metabolic risk, physical activity, and physical fitness in nuclear families from Muzambinho (Minas Gerais, Brazil). SUBJECTS AND METHODS: The study included members of 139 families, comprising 97 fathers (aged 40 ± 7 years), 129 mothers (35 ± 6 years), 136 sons (12 ± 4 years), and 121 daughters (12 ± 5 years). Evaluated markers included (A) body mass index, waist circumference, glycemia, and cholesterolemia, as metabolic risk markers; (B) total weekly volume of physical activity, as a physical activity marker; and (C) relative muscle strength, as a physical fitness marker. Correlations between family members and heritability (h2) were estimated using the software S.A.G.E. RESULTS: Significant familial correlations were obtained between parents-offspring for glycemia and cholesterolemia (both ρ = 0.21, p < 0.05) and relative muscle strength (ρ = 0.23, p < 0.05), and between siblings for waist circumference, glycemia, total weekly volume of physical activity, and relative muscle strength (ρ variation 0.25 to 0.36, p < 0.05). Heritability values were significant for almost all variables (h2 variations: 20% to 57% for metabolic risk markers, 22% for the total weekly volume of physical activity, and 50% for relative muscle strength), except for waist circumference (h2 = 15%, p = 0.059). CONCLUSION: The presence of significant correlations between family members and/or significant heritability strengthens the possible genetic and/or common familial environment influence on metabolic risk markers, total weekly volume of physical activity, and relative muscle strength.

Adaptação transcultural do Empowering Disempowering Motivational Climate Questionnaire para a língua portuguesa e análise da invariância em atletas masculinos brasileiros e portugueses / Adaptación transcultural del Empowering Disempowering Motivational Climate Questionnaire para el portugués y el análisis de la invarianza en los atletas masculinos brasileños y portugués / Cross-cultural adaptation of Empowering Disempowering Motivational Climate Questionnaire for Portuguese language and analysis of invariance in Brazilian and Portuguese male athletes

O objetivo do presente estudo foi o de proceder à tradução e adaptação transcultural do "Empowering and Disempowering Motivational Climate Questionnaire-Coach" (EDMCQ-C) para a língua portuguesa e analisar a invariância da sua estrutura fatorial, quando aplicado a atletas brasileiros e portugueses. A amostra foi constituída por 963 atletas do sexo masculino, praticantes de diferentes desportos (andebol, basquetebol, futebol, futsal e voleibol), com idades compreendidas entre os 11 e os 24 anos (M = 15.04 ± 1.88), sendo 553 brasileiros (M = 15.81 ± 1.91) e 410 portugueses (M = 13.94 ± 1.30). Através do recurso à Análise Fatorial Confirmatória, foi possível verificar a existência de bons índices de ajustamento ao modelo teórico examinado, com uma solução reduzida constituída por 15 itens, distribuídos pelos cinco fatores do instrumento original (χ2/df = 2.38; CFI = 0.97; TLI = 0.96; SRMR = 0.03; RMSEA = 0.04). Complementarmente, a invariância do modelo de medida, quando aplicado a atletas brasileiros e portugueses, foi avaliada através da comparação do modelo com pesos fatoriais fixos e o modelo com coeficientes estruturais livres, tendo o resultado sido de DELTACFI = 0.01. Em conformidade, os resultados encontrados suportam a sugestão de que a versão adaptada para a língua portuguesa do EDMCQ-C evidencia boas propriedades psicométricas, podendo, portanto, constituir-se como uma ferramenta útil para avaliar as perceções de atletas brasileiros e portugueses sobre o clima motivacional que lhes é proporcionado pelos seus treinadores

El objetivo de este estudio fue la adaptación transcultural de la versión en portugués del "Empowering and Disempowering Motivational Climate Questionnaire-Coach" (EDMCQ-C), que evalúa la percepción de los atletas en el clima motivacional proporcionada por el entrenador, e investigar la invariancia factorial entre brasileños y portugueses. La muestra consistía en 963 atletas hombres, practicantes de diferentes deportes (balonmano, baloncesto, fútbol, fustal y voleibol) con edades entre 11 y 24 años (M = 14,15 ± 1.88), de los cuales 553 eran brasileños (M = 15,81 ± 1,91) y 410 atletas portugueses (M = 13,94 ± 1,30). Mediante el análisis factorial confirmatorio fue posible verificar índices de ajuste aceptables al modelo teórico tanto para portugueses (χ2 / df = 1,67, CFI = 0,92, TLI = 0,91; SRMR = 0.06; RMSEA = 0:04) cuanto para brasileños (χ2 / df = 1.92, CFI = 0.90, TLI = 0.89, SRMR = 0.05, RMSEA = 0.04). Los resultados también mostraron que el modelo de medición es invariante entre atletas portuguesas y brasileñas (DELTACFI <0,01). En conclusión, el instrumento puede ser una herramienta útil para analizar la percepción de los atletas brasileños y portugueses al clima motivacional proporcionado por el entrenador

The aim of the present study was to carry out the cross-cultural adaptation of the Portuguese version of "Empowering and Disempowering Motivational Climate" (EDMCQ-C), which evaluates the athletes' perception the motivational climate provided by the coach and to examine the factorial invariance between Brazilians and Portuguese. The sample was composed by 963 male athletes from different sports (handball, basketball, soccer, futsal and volleyball), aged between 11 and 24 (M = 15.04 ± 1.88), of whom 553 were Brazilian (M = 15.81 ± 1.91) and 410 Portuguese athletes (M = 13.94 ± 1.30). The results of the confirmatory factorial analysis found satisfactory adjustment indices of the model for both portuguese (χ2/df = 1.67; CFI = 0.92; TLI = 0.91; SRMR = 0.06; RMSEA = 0.04) and brazilian (χ2/df = 1.92; CFI = 0.90; TLI = 0.89; SRMR = 0.05; RMSEA = 0.04). The results also showed that the model of measurement was invariant between Brazilian and Portuguese athletes (DELTACFI <0.01). In conclusion, the instrument used can be a useful to analyze the perception of Brazilian and Portuguese athletes for the motivational climate provided by the coach

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.

Relação entre atividade física, aptidão física e risco cardiovascular: estudo em muzambinho, minas gerais / Relationship between physical activity, physical fitness and cardiovascular risk: study in muzambinho, minas gerais / Relación entre actividad física, aptitud física y riesgo cardiovascular: estudio en muzambinho, minas gerais

RESUMO Introdução: A relação negativa entre atividade física, aptidão física e risco cardiovascular está bem estabelecida em populações com baixos níveis de atividade física. Objetivo: O presente estudo investigou essa relação em adultos de Muzambinho, Minas Gerais, uma população com alta taxa de indivíduos fisicamente ativos. Métodos: Participaram 237 indivíduos (132 mulheres), na maioria jovens (44,3% entre 20 e 39 anos). Foram avaliados indicadores de risco cardiovascular (índice de massa corporal, circunferência da cintura, glicemia de jejum, colesterolemia de jejum e pressão arterial sistólica e diastólica), atividade física (volume semanal de atividade física total) e aptidão física (aptidão aeróbica e força manual relativa). Resultados: Mais de 90% dos indivíduos foram classificados como ativos (praticavam atividade física por mais de 150 min/semana). A regressão linear identificou associação negativa da força manual relativa e da aptidão aeróbica ao índice de massa corporal e a circunferência da cintura, bem como associação positiva da força manual relativa à pressão arterial diastólica. Os indicadores de atividade física e aptidão física não se associaram ao risco cardiovascular global. Conclusão: Nessa população, a relação inversa entre atividade física, aptidão física e risco cardiovascular limitou-se aos indicadores de aptidão física e aos de obesidade, sugerindo que em populações com alta taxa de indivíduos fisicamente ativos, o aumento da aptidão física, mas não da atividade física, pode ajudar a reduzir a obesidade. Nível de Evidência II; ECRC de menor qualidade.

ABSTRACT Introduction: The negative relationship between physical activity, physical fitness, and cardiovascular risk is well established in populations with low levels of physical activity. Objective: The present study investigated this relationship in adults from Muzambinho, Minas Gerais, a population with a high rate of physically active individuals. Methods: Two hundred and thirty-seven individuals (132 women), mostly young adults (44.3% between 20 and 39 years) were assessed. Cardiovascular risk predictors (body mass index, waist circumference, fasting blood glucose, fasting cholesterol, and systolic and diastolic blood pressure), physical activity (total weekly volume of total physical activity) and physical fitness (aerobic fitness and relative hand strength) were measured. Results: More than 90% of the individuals were classified as active (they practiced physical activity for more than 150 min/week). Linear regression identified a negative association of relative hand strength and aerobic fitness to body mass index and waist circumference, as well as a positive association of relative hand strength with diastolic blood pressure. The indicators of physical activity and physical fitness showed no association with global cardiovascular risk. Conclusion: In this population, the inverse relationship between physical activity, physical fitness and cardiovascular risk was limited to physical fitness and obesity indicators, suggesting that in populations with high rates of physically active individuals, the increase in physical fitness, but not in physical activity, can help reduce obesity. Level of Evidence II; Lesser quality RCT.

RESUMEN Introducción: La relación negativa entre actividad física, aptitud física y riesgo cardiovascular está bien establecida en poblaciones con bajos niveles de actividad física. Objetivo: Este estudio investigó esta relación en adultos de Muzambinho, Minas Gerais, una población con una alta tasa de individuos físicamente activos. Métodos: Participaron 237 individuos (132 mujeres), en su mayoría jóvenes (44,3% entre los 20 y 39 años). Se evaluaron indicadores de riesgo cardiovascular (índice de masa corporal, circunferencia de la cintura, glucosa en ayunas, colesterol en ayunas y presión arterial sistólica y diastólica), actividad física (volumen semanal de actividad física total) y aptitud física (capacidad aeróbica y fuerza relativa de la mano). Resultados: Más del 90% de los individuos fueron clasificados como activos (practicaban actividad física por más de 150 min/semana). La regresión lineal identificó asociación negativa de la fuerza relativa de la mano y la capacidad aeróbica al índice de masa corporal y la circunferencia de la cintura, así como la asociación positiva de la fuerza relativa de la mano a la presión arterial diastólica. Los indicadores de actividad física y aptitud física no se asociaron al riesgo cardiovascular global. Conclusión: En esta población, la relación inversa entre actividad física, aptitud física y riesgo cardiovascular se limitó a los indicadores de aptitud física y obesidad, lo que sugiere que en poblaciones con alta tasa de individuos físicamente activos, el aumento de la aptitud física, pero no de la actividad física, puede ayudar a reducir la obesidad. Nivel de Evidencia II; ECRC de menor calidad.

The Oporto mixed-longitudinal growth, health and performance study. Design, methods and baseline results.

BACKGROUND: Studies concerning child and adolescent growth, development, performance and health aimed at the multiple interactions amongst this complex set of variables are not common in the Portuguese speaking countries. AIM: The aim of this paper is to address the key ideas, methodology and design of the Oporto Growth, Health and Performance Study (OGHPS). SUBJECTS AND METHODS: The OGHPS is a multidisciplinary mixed-longitudinal study whose main purpose is to examine the multiple interactions among biological, environmental and lifestyle indicators that affect growth, development, health and performance of Portuguese adolescents aged 10-18 years old. RESULTS: This study briefly presents baseline results for growth, physical fitness and lifestyle behaviours for those participating in the cross-sectional sample (n ≈ 8000). Approximately 30% were over-fat or obese. On average, boys were more physically fit and active than girls. Few adolescents meet the guidelines for sleep duration (≈10%) and eating habits (16.2-24.8%), while 76-85% meet the recommended levels of moderate-to-vigorous physical activity. CONCLUSIONS: The OGHPS has an innovative approach due to its mixed-longitudinal design and the broad array of variables. Furthermore, subsequent analyses of the longitudinal data will enable a detailed exploration of important factors affecting the growth trajectories of health and performance variables and will also help to identify some of the most opportune times for interventions in terms of health behaviours.

The game variants in Europe. Trends and perspectives during youth competitive stages

AIMS: The aim of this study was to verify how European countries manage the type of game variants and their frequency during different age groups of youth competition. METHODS: Data were collected from the official rules of youth football championships. To identify countries homogenous groups according to their game variants, Two Step Cluster Analysis procedure was used while a nonparametric Kruskal-Wallis test was used to compare the game variants distribution in each Cluster. In order to correlate the game variants with age groups, a Chi-Square independence test and a Spearman ordinal correlation coefficient were used. The results showed there were five clusters with significant differences in their game variants distribution (X2 kw (4) = 22.149; p<0.001; n = 30) and a significant correlation between age group and game variant (χ2(63) = 477.724; p<0.001; n = 30). Specifically, the most used game variants in each age group were the five-a-side (F5) in Under-8; the nine-a-side (F9) in Under-12; the seven-a-side (F7) in Under-9 and Under10; and the eleven-a-side (F11) in and above Under-13. CONCLUSION: These results may contribute to understand the different country perspectives about the competitive game variants of youth football within the European space and its relation with diverse learning philosophies and pathways.(AU)

Genetic and environmental influences on height from infancy to early adulthood: An individual-based pooled analysis of 45 twin cohorts.

Height variation is known to be determined by both genetic and environmental factors, but a systematic description of how their influences differ by sex, age and global regions is lacking. We conducted an individual-based pooled analysis of 45 twin cohorts from 20 countries, including 180,520 paired measurements at ages 1-19 years. The proportion of height variation explained by shared environmental factors was greatest in early childhood, but these effects remained present until early adulthood. Accordingly, the relative genetic contribution increased with age and was greatest in adolescence (up to 0.83 in boys and 0.76 in girls). Comparing geographic-cultural regions (Europe, North-America and Australia, and East-Asia), genetic variance was greatest in North-America and Australia and lowest in East-Asia, but the relative proportion of genetic variation was roughly similar across these regions. Our findings provide further insights into height variation during childhood and adolescence in populations representing different ethnicities and exposed to different environments.

Developmental and physical-fitness associations with gross motor coordination problems in Peruvian children.

The aims of this cross-sectional study were to examine the developmental characteristics (biological maturation and body size) associated with gross motor coordination problems in 5193 Peruvian children (2787 girls) aged 6-14 years from different geographical locations, and to investigate how the probability that children suffer with gross motor coordination problems varies with physical fitness. Children with gross motor coordination problems were more likely to have lower flexibility and explosive strength levels, having adjusted for age, sex, maturation and study site. Older children were more likely to suffer from gross motor coordination problems, as were those with greater body mass index. However, more mature children were less likely to have gross motor coordination problems, although children who live at sea level or at high altitude were more likely to suffer from gross motor coordination problems than children living in the jungle. Our results provide evidence that children and adolescents with lower physical fitness are more likely to have gross motor coordination difficulties. The identification of youths with gross motor coordination problems and providing them with effective intervention programs is an important priority in order to overcome such developmental problems, and help to improve their general health status.

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.

Skeletal Maturation, Body Size, and Motor Coordination in Youth 11-14 Years.

PURPOSE: The objective of this study is to estimate the relative contribution of biological maturation to variance in the motor coordination (MC) among youth and to explore gender differences in the associations. METHODS: Skeletal maturation (Tanner-Whitehouse 3), stature, body mass, and MC (Körperkoordinationstest für Kinder) were assessed in 613 youths, 284 boys and 329 girls 11-14 yr of age. Standardized residuals of skeletal age on chronological age were used as the estimate of skeletal maturity status independent of chronological age. Hierarchical multiple regression analyses were used to analyse associations between skeletal maturity status and MC. RESULTS: Skeletal maturity status by itself, i.e., standardized residuals of skeletal age on chronological age (step 3) explained a maximum of 8.1% of the variance in MC in boys (ΔR3 in the range of 0.0%-8.1%) and 2.8% of the variance in girls (ΔR3 in the range of 0.0%-2.8%), after controlling for stature, body mass and interactions of the standardized residuals of skeletal age on chronological age with stature and body mass. Corresponding percentages for the interactions of the standardized residuals of skeletal age and stature and body mass, after adjusting for stature and body mass (step 2) were 8.7% in boys (ΔR2 in the range of 0.3%-8.7%) and 7.1% in girls (ΔR2 in the range of 0.1%-7.1%). Chow tests suggested structural changes in ß-coefficients in the four MC tests among boys and girls, 12-13 yr. CONCLUSION: The percentage of variance in the four MC tests explained by skeletal maturation was relatively small, but the relationships differed between boys and girls. By inference, other factors, e.g., neuromuscular maturation, specific instruction and practice, sport participation, and others may influence MC at these ages.

An evaluation of a nurse-led rehabilitation programme (the ProBalance Programme) to improve balance and reduce fall risk of community-dwelling older people: A randomised controlled trial.

OBJECTIVE: This study aims to assess the effect of a nurse-led rehabilitation programme (the ProBalance Programme) on balance and fall risk of community-dwelling older people from Madeira Island, Portugal. DESIGN: Single-blind, randomised controlled trial. SETTING: University laboratory. PARTICIPANTS: Community-dwelling older people, aged 65-85, with balance impairments. Participants were randomly allocated to an intervention group (IG; n=27) or a wait-list control group (CG; n=25). INTERVENTION: A rehabilitation nursing programme included gait, balance, functional training, strengthening, flexibility, and 3D training. One trained rehabilitation nurse administered the group-based intervention over a period of 12 weeks (90min sessions, 2 days per week). A wait-list control group was instructed to maintain their usual activities during the same time period. OUTCOME: Balance was assessed using the Fullerton Advanced Balance (FAB) scale. The time points for assessment were at zero (pre-test), 12 (post-test), and 24 weeks (follow up). RESULTS: Changes in the mean (SD) FAB scale scores immediately following the 12-week intervention were 5.15 (2.81) for the IG and -1.45 (2.80) for the CG. At follow-up, the mean (SD) change scores were -1.88 (1.84) and 0.75 (2.99) for the IG and CG, respectively. The results of a mixed between-within subjects analysis of variance, controlling for physical activity levels at baseline, revealed a significant interaction between group and time (F (2, 42)=27.89, p<0.001, Partial Eta Squared=0.57) and a main effect for time (F (2, 43)=3.76, p=0.03, Partial Eta Squared=0.15), with both groups showing changes in the mean FAB scale scores across the three time periods. A significant main effect comparing the two groups (F (1, 43)=21.90, p<0.001, Partial Eta Squared=0.34) confirmed a clear positive effect of the intervention when compared to the control. CONCLUSION: This study demonstrated that the rehabilitation nursing programme was effective in improving balance and reducing fall risk in a group of older people with balance impairment, immediately after the intervention. A decline in balance was observed for the IG after a period of no intervention. CLINICAL TRIAL REGISTRATION NUMBER: ACTRN12612000301864.

Relationship between physical activity, physical fitness and multiple metabolic risk in youths from Muzambinho's study.

Negative associations between physical activity (PA), physical fitness and multiple metabolic risk factors (MMRF) in youths from populations with low PA are reported. The persistence of this association in moderately-to highly active populations is not, however, well established. The aim of the present study was to investigate this association in a Brazilian city with high frequency of active youths. We assessed 122 subjects (9.9 ± 1.3 years) from Muzambinho city. Body mass index, waist circumference, glycaemia, cholesterolaemia, systolic and diastolic blood pressures were measured. Maximal handgrip strength and one-mile walk/run test were used. Leisure time PA was assessed by interview. Poisson regression was used in the analysis. The model explained 11% of the total variance. Only relative muscular strength and one-mile walk/run were statistically significant (p < .05). Those who needed more time to cover the one-mile walk/run test had an increased in metabolic risk of 11%, and those with greater strength reduced the risk by about 82%. In conclusion, children and youths from an active population who need less time to cover the one-mile walk/run test or who had greater muscular strength showed a reduced metabolic risk. These results suggest that even in children and youths with high leisure time PA, a greater aerobic fitness and strength might help to further reduce their MMRF.

Zygosity Differences in Height and Body Mass Index of Twins From Infancy to Old Age: A Study of the CODATwins Project.

A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m2 in childhood and adolescence and up to 0.2 kg/m2 in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes.

Tracking and its applicability to Physical Education and Sport / A noção de tracking e sua aplicação à Educação Física e ao Esporte

Abstract Tracking refers to the idea of maintaining a relative position within a given group of individuals as they change in time. This paper presents several approaches to study and analyze tracking (i.e., stability and predictability) and its application in physical education and sport. We will use data from a mixed-longitudinal study conducted in the city of Porto, Portugal, comprising 486 girls that were divided into two age cohorts: 12-14 years and 14-16 years. Body mass index (BMI) was the chosen variable in all statistical analyses of tracking. Statistical techniques to describe tracking included: autocorrelations, Foulkes & Davis gamma and Goldstein constancy index. Regardless of statistical procedure used, tracking BMI was moderate to high in each cohort, which could be due to the short follow-up period. However, each tracking statistics showed different aspects of inter-individual differences in intra-individual changes of girls' BMI. The use of any of the suggested procedures to study aspects of stability and predictability (i.e., tracking) in longitudinal studies requires a careful scrutiny of main goals and hypotheses to be tested.

Resumo O termo Tracking refere-se à noção de manutenção de posição relativa de valores de um dado grupo de sujeitos em função do tempo. O presente artigo apresenta diversas técnicas de estudo e análise do tracking (i.e., estabilidade e previsibilidade). Os dados utilizados provêm de um estudo longitudinal-misto da Região do Grande Porto, Portugal, compreendendo 486 meninas, divididas em duas coortes que abrangem as faixas etárias dos 12 aos 14 e dos 14 aos 16 anos. A variável eleita para as análises foi o índice de massa corporal (IMC). Os procedimentos estatísticos utilizados para descrever o tracking foram: autocorrelações, gama de Foulkes & Davis e índice de constância de Goldstein. Independentemente da estatística utilizada e face à curta duração do estudo, o tracking do IMC foi moderado a elevado em cada coorte. Contudo, cada procedimento de análise mostrou aspetos distintos das diferenças interindividuais nas mudanças intraindividuais do IMC das meninas. O uso parcimonioso de qualquer um dos procedimentos sugeridos para estudar aspetos da estabilidade e previsibilidade (i.e., do tracking) em estudos longitudinais exige o estabelecimento muito criterioso dos objetivos e hipóteses a serem testados.

The CODATwins Project: The Cohort Description of Collaborative Project of Development of Anthropometrical Measures in Twins to Study Macro-Environmental Variation in Genetic and Environmental Effects on Anthropometric Traits.

For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes.

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.

Skeletal maturation, fundamental motor skills and motor coordination in children 7-10 years.

Relationships between skeletal maturation and fundamental motor skills and gross motor coordination were evaluated in 429 children (213 boys and 216 girls) 7-10 years. Skeletal age was assessed (Tanner-Whitehouse 2 method), and stature, body mass, motor coordination (Körperkoordinations Test für Kinder, KTK) and fundamental motor skills (Test of Gross Motor Development, TGMD-2) were measured. Relationships among chronological age, skeletal age (expressed as the standardised residual of skeletal age on chronological age) and body size and fundamental motor skills and motor coordination were analysed with hierarchical multiple regression. Standardised residual of skeletal age on chronological age interacting with stature and body mass explained a maximum of 7.0% of the variance in fundamental motor skills and motor coordination over that attributed to body size per se. Standardised residual of skeletal age on chronological age alone accounted for a maximum of 9.0% of variance in fundamental motor skills, and motor coordination over that attributed to body size per se and interactions between standardised residual of skeletal age on chronological age and body size. In conclusion, skeletal age alone or interacting with body size has a negligible influence on fundamental motor skills and motor coordination in children 7-10 years.