Portuguese research on physical education and sport didactics-a critical discussion.

This article presents a discussion of research in Physical Education and Sport Didactics in Portugal. It starts by situating it from an historical perspective, placing the 1980s as the beginning era, mainly based on the studies provided by the two first Physical Education higher education institutes of the country. The initial research, first based on master and doctoral dissertations, progressed to ongoing projects that have been disseminated in international and national journals and books. This development is also reported from the theoretical, conceptual, and methodological perspectives, showing how it has informed the quality of Physical Education and teacher education as the two main research strands to be described, however, acknowledging that a strand on sports coaching and coach education exists. On teaching Physical Education, the article discusses the elements relative to the teacher and to the student, focusing from the immediate and short-term to the distant and long-term events that lead into young adulthood's active lifestyles. In this analysis, research on curriculum and assessment are also reported. On physical education teacher education, the article shows the prevalence of the post-primary Physical Education to argue for the need for more research on primary-level education, and discusses the diverse foci from initial teacher education to in-service education practises. In line with current trends in research, we suggest a set of four features for the future research agenda: (1) addressing short to long-term outcomes of Physical Education; (2) adopting multifactorial and multi-layered perspectives of analysis; (3) embracing inter- and multidisciplinary designs; and (4) taking comparative perspectives within and between European countries, and between Europe and other continents. We conclude that these features need to focus on four levels of integration and cooperation: (a) integration between the research initiatives and the needs of the professional field; (b) integration between research on teaching and learning, teacher education and the curriculum; (c) cooperation between the different national higher education and professional institutions; and (d) integration in the international research agenda by leading and participating in project partnerships which are needed to fully and effectively implement such agenda.

Basic Motor Competencies of 6- to 8-Year-Old Primary School Children in 10 European Countries: A Cross-Sectional Study on Associations With Age, Sex, Body Mass Index, and Physical Activity.

Basic motor competencies (BMC) are a prerequisite for children to be physically active, participate in sports and thus develop a healthy, active lifestyle. The present study provides a broad screening of BMC and associations with age, sex, body mass index (BMI) and extracurricular physical activity (PA) in 10 different European countries. The different country and regional contexts within Europe will offer a novel view on already established BMC associations. The cross-sectional study was conducted in 11 regions in 10 European countries in 2018. The motor competence areas, object movement (OM) and self-movement (SM), were assessed using the MOBAK-1-2 test instrument in 3758 first and second graders (age: M = 6.86 ± 0.60 years; 50% girls) during Physical Education classes. Children were questioned about their extracurricular PA and age. Their body weight and height were measured in order to calculate BMI. Statistical analyses included variances and correlations. The results showed significant differences in BMC levels between countries (OM: F = 18.74, p < 0.001, η2 = 0.048; SM: F = 73.10, p < 0.001, η2 = 0.163) whereas associations between BMC and correlates were similar. Boys performed significantly better in OM while girls performed better in SM. Age was consistently positively related to OM and SM with older children reaching higher levels of BMC than younger ones. While participation rates for extracurricular PA differed widely, participation in ball sports was correlated with OM and SM. Participation in individual sports showed a significant association with SM. In summary, BMC levels of children seem to depend on where they live and are strongly related to their participation in extracurricular PA. Therefore, education and health policies, in order to enhance motor competence development and PA participation, are recommended. Further research on country-specific Physical Education frameworks and their influence on BMC will provide more insights into structural factors and cultural characteristics of BMC development. On a school level, support tools and educational materials for teachers about BMC may enable children to achieve a basic level of motor competencies through Physical Education, contributing to lifelong participation in PA.

A school-based intervention for a better future: study protocol of Sintra Grows Healthy.

BACKGROUND: Preventing childhood obesity is a public health challenge of the twenty-first century and it must be a priority. Governments play a major role in creating and supporting a healthy school environment and should prioritise actions to improve children's health. Sintra Grows Healthy aims to promote healthy lifestyles to prevent childhood obesity and improve children's health-related quality of life and social and emotional skills, through the development of a school evidence-based and sustainable model. METHODS: This protocol describes a quasi-experimental design and community-based participatory research. The participants included in the study are the school community of Portuguese public primary schools from the municipality of Sintra. Data will be collected on demographic and socio-economic characterization, nutritional status, eating habits and behaviours, physical activity, sedentary behaviours and sleep, health-related quality of life, and social and emotional skills. DISCUSSION: There is evidence to support interventions in school settings as strategies for obesity prevention. Up-to-date homogeneous and community-based interventions for preventing childhood obesity are lacking, therefore Sintra Grows Healthy intends to fill this gap. Furthermore, Sintra Grows Healthy aims to contribute with relevant scientific findings that will allow the development of better strategies for policymakers and society to manage this major public health problem.

MOBAK 1 Assessment in Primary Physical Education: Exploring Basic Motor Competences of Portuguese 6-Year-Olds.

Children's motor competence is known to have a determinant role in learning and engaging later in complex motor skills and, thus, in physical activity. The development of adequate motor competence is a central aim of physical education, and assuring that pupils are learning and developing motor competence depends on accurate assessment protocols. The MOBAK 1 test battery is a recent instrument developed to assess motor competence in primary physical education. This study used the MOBAK 1 to explore motor competence levels and gender differences among 249 ( Mage = 6.3, SD = 0.5 years; 127 girls and 122 boys) Grade 1 primary school Portuguese children. On independent sample t tests, boys presented higher object movement motor competence than girls (boys: M = 5.8, SD = 1.7; girls: M = 4.0, SD = 1.7; p < .001), while girls were more proficient among self-movement skills (girls: M = 5.1, SD = 1.8; boys: M = 4.3, SD = 1.7; p < .01). On "total motor competence," boys ( M = 10.3, SD = 2.6) averaged one point ahead of girls ( M = 9.1, SD = 2.9). The percentage of girls in the first quartile of object movement was 18.9%, while, for "self movement," the percentage of boys in the first quartile was almost double that of girls (30.3% and 17.3%, respectively). The confirmatory model to test for construct validity confirmed the assumed theoretical two-factor structure of MOBAK 1 test items in this Portuguese sample. These results support the MOBAK 1 instrument for assessing motor competence and highlighted gender differences, of relevance to intervention efforts.

Skeletal mass in adolescent male athletes and nonathletes: relationships with high-impact sports.

Dias Quiterio, AL, Canero, EA, Baptista, FM, and Sardinha, LB. Skeletal mass in adolescent male athletes and nonathletes: relationships with high-impact sports. J Strength Cond Res 25(12): 3439-3447, 2011-This study examined the relationships between the practice of different categories of sports (high-impact vs. nonimpact) and bone status in adolescent male athletes and investigated differences from an age-matched control group. A total of 54 adolescent male athletes and 26 adolescent nonathletes were evaluated. Bone mineral density, bone mineral content (BMC), and bone area at the whole-body, limbs, and lumbar spine were determined by dual-energy x-ray absorptiometry, along with total and regional fat-free mass and body fat. The high-impact group included 34 athletes: 9 gymnasts, 18 basketball players, and 7 handball players (age: 15.7 ± 1.6 years; weight: 72.0 ± 15.0 kg; height: 178.5 ± 12.5 cm). The nonimpact group consisted of 20 swimmers (age: 16.4 ± 2.5 years; weight: 66.9 ± 10.4 kg; height: 173.7 ± 10.9 cm). The nonathletic control group included 26 male adolescents (age: 15.9 ± 2.8 years; weight: 64.7 ± 16.3 kg; height: 168.6 ± 15.1 cm). No differences were observed between the nonimpact and the control group in all bone variables, before and after adjustments for maturation level, body weight, and height (p > 0.05). After adjustments for these variables, the high-impact group displayed greater bone mass in most of the measured sites when compared to the other 2 groups (p < 0.001). Subjects in the nonimpact group showed lower values of BMC, particularly in the lower limbs, than both the high-impact and the nonathletic control groups (p < 0.05) after adjustments for maturation, high, and fat-free mass. This study reinforces the positive associations between high-impact physical activities and skeletal health in adolescent boys.

Are skinfold-based models accurate and suitable for assessing changes in body composition in highly trained athletes?

This study was designed to assess the usefulness of skinfold (SKF) equations developed by Jackson and Pollock (JP) and by Evans (Ev) in tracking body composition changes (relative fat mass [%FM], absolute fat mass [FM], and fat-free mass [FFM]) of elite male judo athletes before a competition using a 4-compartment (4C) model as the reference method. A total of 18 male, top-level (age: 22.6 +/- 2.9 yr) athletes were evaluated at baseline (weight: 73.4 +/- 7.9 kg; %FM4C: 7.0 +/- 3.3%; FM4C: 5.1 +/- 2.6 kg; and FFM4C: 68.3 +/- 7.3 kg) and before a competition (weight: 72.7 +/- 7.5 kg; %FM4C: 6.5 +/- 3.4%; FM4C: 4.8 +/- 2.6 kg; and FFM4C: 67.9 +/- 7.1 kg). Measures of body density assessed by air displacement plethysmography, bone mineral content by dual energy X-ray absorptiometry, and total-body water by bioelectrical impedance spectroscopy were used to estimate 4C model %FM, FM, and FFM. Seven SKF site models using both JP and Ev were used to estimate %FM, FM, and FFM along with the simplified Ev3SKF site. Changes in %FM, FM, and FFM were not significantly different from the 4C model. The regression model for the SKF in question and the reference method did not differ from the line of identity in estimating changes in %FM, FM, and FFM. The limits of agreement were similar, ranging from -3.4 to 3.6 for %FM, -2.7 to 2.5 kg for FM, and -2.5 to 2.7 kg for FFM. Considering the similar performance of both 7SKF- and 3SKF-based equations compared with the criterion method, these data indicate that either the 7- or 3-site SFK models are not valid to detect %FM, FM, and FFM changes of highly trained athletes. These results highlighted the inaccuracy of anthropometric models in tracking desired changes in body composition of elite male judo athletes before a competition.

Total body water measurements in adolescent athletes: a comparison of six field methods with deuterium dilution.

-Assessing hydration, that is, total body water (TBW) in adolescent athletes should be part of a comprehensive training program. However, there are no specific methods to assess TBW in young athletes. Moreover, the use of traditional techniques developed in healthy youths, based on a 2-compartment model, may yield inaccurate TBW estimates in young athletes. Therefore, the purpose of this study was to assess the accuracy of TBW non-reference field methods with a criterion method (i.e., deuterium dilution) in 118 adolescent athletes. Body volume was assessed by air displacement plethysmography, bone mineral was measured by dual-energy X-ray absorptiometry, and TBW by deuterium dilution. Non-reference TBW methods included 2 bioelectrical impedance analysis techniques (Tanita Body Composition Analyzer, model TBF-310) and bioelectrical impedance spectroscopy (BIS) (model 4000B); the Lohman's hydration constants of fat-free mass (FFM); and 3 derived anthropometric equations developed, respectively, by Kushner et al., Wells et al., and Morgenstern et al. The highest accuracy between TBW estimates and the reference model in both girls and boys was observed using the Lohman's constants (r2= 0.94, SEE = 1.56 kg; r2 = 0.92, SEE = 2.42 kg, respectively; p < 0.001), followed by both foot-to-foot Tanita (r2 = 0.88, SEE = 2.15 kg; r2 = 0.87, SEE = 3.01 kg, respectively; p < 0.001) and BIS (r2 = 0.92, SEE = 1.70 kg; r2 = 0.87, SEE = 3.04 kg, respectively; p < 0.001) with slopes and intercepts not significantly different from the line of identity. The regressions between anthropometric equations and the criterion method deviated from the line of identity (p < 0.05). The practical application of this study is that the specific constants of FFM hydration developed by Lohman seem to accurately estimate TBW in adolescent athletes. Foot-to-foot Tanita and BIS were also found to be valid and non-biased tools for predicting TBW. It would appear that the 3 anthropometric equations used are not appropriate for young athletes.

Anthropometric models to predict appendicular lean soft tissue in adolescent athletes.

PURPOSE: Skeletal muscle (SM), which is found mainly within the appendicular lean soft tissue (ALST) compartment, is a biological important body compartment. Simple and accurate methods to estimate both SM and ALST remain difficult to obtain. We aimed to develop and to cross-validate anthropometric models for ALST in athletes, using dual-energy x-ray absorptiometry (DXA) as the reference method. METHODS: ALST equations were developed in 176 athletic boys (15.0 +/- 2.8 yr; 64.5 +/- 15.8 kg; 1.72 +/- 0.15 m) and 92 athletic girls (14.6 +/- 2.8 yr; 53.0 +/- 13.1 kg; 1.61 +/- 0.13 m). Skinfolds were measured at the triceps, the thigh, and medial calf, and circumferences were measured at the midupper arm, the midthigh, and the midcalf. ALST was assessed using DXA (QDR-4500; Hologic, Walthman, MA; fan-beam mode). Two models were developed: a body weight model (WHt model) and a corrected muscle girth model (CMG model, which included the parameters height x CAG, height x CTG, and height x CCG, where CAG is corrected arm girth, CTG is corrected thigh girth, and CCG is the corrected calf). Simple regression analysis was used to identify the best model fit. The equations were internally cross-validated using the predicted residual sum of squares method, and performance of new equations was analyzed by regression analysis and agreement between methods. RESULTS: The new WHt model generated the following equation: ALST = -20.338 + 0.199(W) + 3.294(gender) + 14.230(height) + 0.192(age), where gender = 1 for male and 0 for female. The CMG model produced the following equation: ALST = 3.260 + 0.002(height x CTG) + 0.007(height x CAG) + 0.003(height x CCG). WHt equation had an R = 0.91 and an SEE = 2.00 kg, whereas CMG equation presented an R = 0.93 and an SEE = 1.80 kg. In both equations, slopes and intercepts did not differ from the line of identity; no mean differences between predicted and measured values and no trend line were observed (P > 0.05). CONCLUSIONS: Both models accurately predict ALST in young athletes, affording a practical means to quantify this compartment.

Objectively measured time spent sedentary is associated with insulin resistance independent of overall and central body fat in 9- to 10-year-old Portuguese children.

OBJECTIVE: We examined the independent relationships between objectively measured physical activity and insulin resistance in Portuguese children. RESEARCH DESIGN AND METHODS: This is a school-based, cross-sectional study in 147 randomly selected girls (aged 9.8 +/- 0.3 years; 27.8 +/- 9.3% body fat) and 161 boys (aged 9.8 +/- 0.3 years; 22.0 +/- 9.2% body fat). Physical activity was assessed by the Actigraph accelerometer for 4 days and summarized as time spent sedentary (accelerometer counts <500/min), in light-intensity (accelerometer counts 500-2,000/min), and in moderate- and vigorous-intensity activity (accelerometer counts >2,001/min). We measured total and central fat mass by dual-energy X-ray absorptiometry. Insulin resistance was expressed as the homeostasis model assessment score. RESULTS: Time (min/day) spent sedentary was significantly and positively associated with insulin resistance (beta-coefficient = 0.001 [95% CI 0.0002-0.002]; P = 0.013). Time spent in moderate- and vigorous-intensity physical activity (-0.002 [-0.003 to -0.001]; P = 0.0009) and overall physical activity (-0.001 [-0.008 to 0.003]; P < 0.0001) were significantly and inversely associated with insulin resistance. All associations remained statistically significant, although they were attenuated after further adjustments for sex, birth weight, sexual maturity, and total or central fat mass (P < 0.03). CONCLUSIONS: Physical activity is associated with insulin resistance independent of total and central fat mass in children. Our results emphasize the importance of decreasing sedentary behavior and increasing time spent in moderate- and vigorous-intensity activity in children, which may have beneficial effects on metabolic risk factors regardless of the degree of adiposity.