Association of parents' physical activity and weight status with obesity and metabolic risk of their offspring.

Our aim was to analyze the joint association of parental characteristics and offspring obesity indicators with metabolic risk in adolescents. A cross-sectional study was carried out with 972 adolescents and their parents. We observed that overweight adolescents who have a normal weight mother show lower metabolic risk in comparison with their counterparts with overweight mothers. In conclusion, mother's weight status moderates the relationship between offspring' obesity indicators and metabolic risk in adolescents.

Reference Percentiles for Bioelectrical Phase Angle in Athletes.

The present study aimed to develop reference values for bioelectrical phase angle in male and female athletes from different sports. Overall, 2224 subjects participated in this study [1658 males (age 26.2 ± 8.9 y) and 566 females (age 26.9 ± 6.6 y)]. Participants were categorized by their sport discipline and sorted into three different sport modalities: endurance, velocity/power, and team sports. Phase angle was directly measured using a foot-to-hand bioimpedance technology at a 50 kHz frequency during the in-season period. Reference percentiles (5th, 15th, 50th, 85th, and 95th) were calculated and stratified by sex, sport discipline and modality using an empirical Bayesian analysis. This method allows for the sharing of information between different groups, creating reference percentiles, even for sports disciplines with few observations. Phase angle differed (men: p < 0.001; women: p = 0.003) among the three sport modalities, where endurance athletes showed a lower value than the other groups (men: vs. velocity/power: p = 0.010, 95% CI = -0.43 to -0.04; vs. team sports: p < 0.001, 95% CI = -0.48 to -0.02; women: vs. velocity/power: p = 0.002, 95% CI = -0.59 to -0.10; vs. team sports: p = 0.015, 95% CI = -0.52 to -0.04). Male athletes showed a higher phase angle than female athletes within each sport modality (endurance: p < 0.01, 95% CI = 0.63 to 1.14; velocity/power: p < 0.01, 95% CI = 0.68 to 1.07; team sports: p < 0.01, 95% CI = 0.98 to 1.23). We derived phase angle reference percentiles for endurance, velocity/power, and team sports athletes. Additionally, we calculated sex-specific references for a total of 22 and 19 sport disciplines for male and female athletes, respectively. This study provides sex- and sport-specific percentiles for phase angle that can track body composition and performance-related parameters in athletes.

Association of parents' physical activity and weight status with obesity and metabolic risk of their offspring / Associação do status de atividade física e peso dos pais com os indicadores de obesidade e risco metabólico dos filhos

Abstract Our aim was to analyze the joint association of parental characteristics and offspring obesity indicators with metabolic risk in adolescents. A cross-sectional study was carried out with 972 adolescents and their parents. We observed that overweight adolescents who have a normal weight mother show lower metabolic risk in comparison with their counterparts with overweight mothers. In conclusion, mother's weight status moderates the relationship between offspring' obesity indicators and metabolic risk in adolescents.

Resumo Nosso objetivo foi analisar a associação combinada entre características dos pais e indicadores de adiposidade dos filhos com o risco metabólico em adolescentes. Foi realizado estudo transversal com 972 adolescentes e seus pais. Observamos que adolescentes com sobrepeso que possuem mãe com peso normal apresentaram menor risco metabólico em comparação com seus pares com mães que apresentam sobrepeso. Concluímos que o status de peso da mãe modera a relação entre indicadores de obesidade e risco metabólico dos adolescentes.

Identifying children who are susceptible to dropping out from physical activity and sport: a cross-sectional study.

BACKGROUND: Although the benefits of physical activity are clear, adherence to physical activity programs is a challenge, especially during transitional phases of life. OBJECTIVE: We aimed to identify adolescents who were more likely to drop out from physical activity and sports participation, from childhood to adolescence. DESIGN AND SETTING: This was a cross-sectional study on retrospective data regarding childhood activity among 803 Brazilian adolescents. The study was conducted at public schools in Londrina, Paraná, in 2011. METHODS: Habitual physical activity, sports participation during childhood, parental physical activity, socioeconomic status and perception of social relationships were self-reported. Cardiorespiratory fitness was estimated via a 20-m shuttle-run test and somatic maturation was estimated from the age at peak height velocity. RESULTS: Our results provided evidence that girls (physical activity: odds ratio, OR: 4.37 [95% confidence interval, CI: 1.86-10.3]; sports: OR: 2.65 [95% CI: 1.39-5.05]) and adolescents with low cardiorespiratory fitness (physical activity: OR: 1.77 [95% CI: 1.13-2.78]; sports: OR: 1.62 [95% CI: 1.15-2.26]) were more likely to drop out from active behaviors. Children with inactive mothers and inactive fathers (OR: 3.55 [95% CI: 1.12-11.3]) also showed a higher dropout rate from physical activity. Adolescents with negative perceptions of friendships (OR: 2.33 [95% CI: 1.21-4.47]) were more likely to drop out from sports. CONCLUSIONS: Higher dropout rates from active lifestyles during childhood were observed among girls and adolescents with low cardiorespiratory fitness. Parental inactivity and negative perceptions of friendships were also potential risk factors for discontinuation of childhood physical activity and sports.

The usefulness of Tanita TBF-310 for body composition assessment in Judo athletes using a four-compartment molecular model as the reference method.

Body composition assessment at the molecular level is relevant for the athletic population and its association with high performance is well recognized. The four-compartment molecular model (4C) is the reference method for fat mass (FM) and fat-free mass (FFM) estimation. However, its implementation in a real context is not feasible. Coaches and athletes need practical body composition methods for body composition assessment, and the bioelectrical impedance analysis method (BIA) is usually seen as a useful alternative. The aim of this study was to test the validity of BIA (Tanita, TBF-310) to determine the FM and FFM of elite judo athletes. A total of 29 males were evaluated in a period of weight stability using the reference method (4C) and the alternative method (Tanita, TBF-310). Regarding the 4C method, total-body water was assessed by deuterium dilution, bone mineral by DXA, and body volume by air displacement plethysmography. The slops and intercepts differed from 1 (0.39 and 1.11) and 0 (4.24 and -6.41) for FM and FFM, respectively. FM from Tanita TBF-310 overestimated the 4C method by 0.2 kg although no differences were found for FFM. Tanita TBF-310 explained 21% and 72% respectively in the estimation of absolute values of FM and FFM from the 4C method. Limits of agreement were significant, varying from -6.7 kg to 7.0 kg for FM and from -8.9 kg to 7.5 kg for FFM. In conclusion, TBF-310 Tanita is not a valid alternative method for estimating body composition in highly trained judo athletes.

The usefulness of Tanita TBF-310 for body composition assessment in Judo athletes using a four-compartment molecular model as the reference method

SUMMARY Body composition assessment at the molecular level is relevant for the athletic population and its association with high performance is well recognized. The four-compartment molecular model (4C) is the reference method for fat mass (FM) and fat-free mass (FFM) estimation. However, its implementation in a real context is not feasible. Coaches and athletes need practical body composition methods for body composition assessment, and the bioelectrical impedance analysis method (BIA) is usually seen as a useful alternative. The aim of this study was to test the validity of BIA (Tanita, TBF-310) to determine the FM and FFM of elite judo athletes. A total of 29 males were evaluated in a period of weight stability using the reference method (4C) and the alternative method (Tanita, TBF-310). Regarding the 4C method, total-body water was assessed by deuterium dilution, bone mineral by DXA, and body volume by air displacement plethysmography. The slops and intercepts differed from 1 (0.39 and 1.11) and 0 (4.24 and -6.41) for FM and FFM, respectively. FM from Tanita TBF-310 overestimated the 4C method by 0.2 kg although no differences were found for FFM. Tanita TBF-310 explained 21% and 72% respectively in the estimation of absolute values of FM and FFM from the 4C method. Limits of agreement were significant, varying from -6.7 kg to 7.0 kg for FM and from -8.9 kg to 7.5 kg for FFM. In conclusion, TBF-310 Tanita is not a valid alternative method for estimating body composition in highly trained judo athletes.

RESUMO A avaliação da composição corporal ao nível molecular é relevante para a população esportiva e sua associação com o alto rendimento é bem reconhecida. O modelo molecular a quatro compartimentos (4C) é o método de referência para as estimativas de massa gorda (MG) e massa livre de gordura (MLG). No entanto, sua implementação no contexto real não é viável. Técnicos e atletas precisam de métodos práticos de composição corporal para a avaliação da composição corporal e o método de análise de impedância bioelétrica (BIA) é geralmente visto como uma alternativa útil. O objetivo deste estudo foi testar a validade da BIA (Tanita, TBF-310) na determinação de MG e MLG em atletas de elite de judô. Um total de 29 atletas masculinos foi avaliado em um período de estabilidade de peso usando o método de referência (4C) e o método alternativo (Tanita, TBF-310). Em relação ao método a 4C, a água corporal total foi avaliada pela diluição de deutério, mineral ósseo por DXA e volume corporal por pletismografia por deslocamento de ar. Os declives e interceções diferiram de 1 (0,39 e 1,11) e 0 (4,24 e -6,41) para MG e MLG, respectivamente. A MG da Tanita TBF-310 superestimou o método 4C em 0,2 kg, embora não tenham sido encontradas diferenças para MLG. A Tanita TBF-310 explicou 21% e 72%, respectivamente, na estimativa dos valores absolutos de MG e MLG do método a 4C. Os limites de concordância foram grandes, variando de -6,7 kg a 7,0 kg para MG e de -8,9 kg a 7,5 kg para MLG. Em conclusão, a TBF-310 Tanita não é um método alternativo válido para estimar a composição corporal em judocas altamente treinados.

Identifying children who are susceptible to dropping out from physical activity and sport: a cross-sectional study

ABSTRACT BACKGROUND: Although the benefits of physical activity are clear, adherence to physical activity programs is a challenge, especially during transitional phases of life. OBJECTIVE: We aimed to identify adolescents who were more likely to drop out from physical activity and sports participation, from childhood to adolescence. DESIGN AND SETTING: This was a cross-sectional study on retrospective data regarding childhood activity among 803 Brazilian adolescents. The study was conducted at public schools in Londrina, Paraná, in 2011. METHODS: Habitual physical activity, sports participation during childhood, parental physical activity, socioeconomic status and perception of social relationships were self-reported. Cardiorespiratory fitness was estimated via a 20-m shuttle-run test and somatic maturation was estimated from the age at peak height velocity. RESULTS: Our results provided evidence that girls (physical activity: odds ratio, OR: 4.37 [95% confidence interval, CI: 1.86-10.3]; sports: OR: 2.65 [95% CI: 1.39-5.05]) and adolescents with low cardiorespiratory fitness (physical activity: OR: 1.77 [95% CI: 1.13-2.78]; sports: OR: 1.62 [95% CI: 1.15-2.26]) were more likely to drop out from active behaviors. Children with inactive mothers and inactive fathers (OR: 3.55 [95% CI: 1.12-11.3]) also showed a higher dropout rate from physical activity. Adolescents with negative perceptions of friendships (OR: 2.33 [95% CI: 1.21-4.47]) were more likely to drop out from sports. CONCLUSIONS: Higher dropout rates from active lifestyles during childhood were observed among girls and adolescents with low cardiorespiratory fitness. Parental inactivity and negative perceptions of friendships were also potential risk factors for discontinuation of childhood physical activity and sports.

Prenatal, biological and environmental factors associated with physical activity maintenance from childhood to adolescence.

Our aim was to identify prenatal, biological and environmental correlates of child to adolescence physical activity maintenance in 1,186 Brazilian youth (525 boys) aged between 10 and 16 years. Current and former physical activity levels were obtained cross-sectionally through questionnaires. As potential correlates, parent's activity levels, socioeconomic status and offspring's birth weight were self-reported by parents. Somatic maturation was estimated by the peak of height velocity. Logistic regression analyses revealed that, regardless of chronological age, males were more likely to be active in childhood (OR = 1.73 [CI 95% = 1.33 to 2.27]) and to maintain physical activity (adjusted by chronological age, sex, birth weight and mother's physical activity) (OR = 3.58 [CI 95% = 2.32 to 5.54]), as well as late maturing adolescents (OR = 2.52 [CI 95% = 1.02 to 6.22]). Adolescents whose mother was inactive (OR = 0.31 [CI 95% = 0.11 to 0.86]) also had a lower probability of maintaining physical activity. Thus, girls, adolescents born with low weight and those with inactive mother are less likely to maintain physical activity levels from childhood to adolescence.

Prenatal, biological and environmental factors associated with physical activity maintenance from childhood to adolescence / Fatores pré-natais, biológicos e ambientais associados à manutenção da atividade física da infância à adolescência

Abstract Our aim was to identify prenatal, biological and environmental correlates of child to adolescence physical activity maintenance in 1,186 Brazilian youth (525 boys) aged between 10 and 16 years. Current and former physical activity levels were obtained cross-sectionally through questionnaires. As potential correlates, parent's activity levels, socioeconomic status and offspring's birth weight were self-reported by parents. Somatic maturation was estimated by the peak of height velocity. Logistic regression analyses revealed that, regardless of chronological age, males were more likely to be active in childhood (OR = 1.73 [CI 95% = 1.33 to 2.27]) and to maintain physical activity (adjusted by chronological age, sex, birth weight and mother's physical activity) (OR = 3.58 [CI 95% = 2.32 to 5.54]), as well as late maturing adolescents (OR = 2.52 [CI 95% = 1.02 to 6.22]). Adolescents whose mother was inactive (OR = 0.31 [CI 95% = 0.11 to 0.86]) also had a lower probability of maintaining physical activity. Thus, girls, adolescents born with low weight and those with inactive mother are less likely to maintain physical activity levels from childhood to adolescence.

Resumo O nosso objetivo foi identificar correlatos pré-natais, biológicos e ambientais da manutenção da prática de atividade física da infância à adolescência em 1.186 adolescentes (525 meninos), com idade entre 10 e 16 anos. Prática de atividade física na infância (retrospectiva) e adolescência (atual) foi obtida através de questionários. O nível de atividade física dos pais, nível socioeconômico e peso ao nascer dos filhos foram relatados pelos pais. Maturação somática foi estimada por meio do pico de velocidade de crescimento. Regressões logísticas revelam que independentemente da idade cronológica, meninos apresentaram maior probabilidade de ser ativos na infância (OR = 1.73 [CI 95% = 1.33 - 2.27]) e manter a prática de atividade física (ajustado por idade cronológica, sexo, peso ao nascer e atividade física da mãe) (OR = 3.58 [CI 95% = 2.32 - 5.54]), bem como adolescentes com maturação tardia (OR = 2.52 [CI 95% = 1.02 - 6.22]), adolescentes com a mãe inativa (OR = 2.52 [CI 95% = 1.02 - 6.22]), também apresentaram menor probabilidade de manter o nível de atividade física. Portanto, meninas, adolescentes nascidos com baixo peso e aqueles cuja mãe é inativa possuem menor probabilidade de manter o nível de atividade física da infância à adolescência.

Prevalence of physical activity through the practice of sports among adolescents from Portuguese speaking countries.

This study evaluated the prevalence of physical activity through the practice of sports in adolescents from schools in two Brazilian cities and a Portuguese school, and its association with independent variables, such as gender and age. A cross-sectional study was conducted of schoolchildren from two cities in Brazil and one in Portugal. The total study sample was 3694 subjects (1622 males and 1872 females). Physical activity levels were assessed using Baecke's questionnaire. Body weight was measured on electronic scales and stature was measured with a portable wooden stadiometer. Numerical variables were expressed as mean, categorical variables were expressed as percentages and the chi-square test analyzed associations. The prevalence of no sport was high (39.7%), being higher in the Portuguese school than in the Brazilian schools (p < 0.001). Irrespective of being an adolescent in a Brazilian or Portuguese school, boys showed higher engagement in sports practice than girls (p < 0.001). In both, differences were identified between adolescents aged 13 to 15 (P = 0.001) and 16 to 17 (P = 0.001). The prevalence of physical inactivity among schoolchildren from two cities in Brazil and a school in Portugal was high, with the girls practicing less sport than the boys and with this imbalance likely to be higher in adolescents.

Prevalence of physical activity through the practice of sports among adolescents from Portuguese speaking countries / Prevalência de atividade física através da prática esportiva em adolescentes de países de língua Portuguesa

This study evaluated the prevalence of physical activity through the practice of sports in adolescents from schools in two Brazilian cities and a Portuguese school, and its association with independent variables, such as gender and age. A cross-sectional study was conducted of schoolchildren from two cities in Brazil and one in Portugal. The total study sample was 3694 subjects (1622 males and 1872 females). Physical activity levels were assessed using Baecke's questionnaire. Body weight was measured on electronic scales and stature was measured with a portable wooden stadiometer. Numerical variables were expressed as mean, categorical variables were expressed as percentages and the chi-square test analyzed associations. The prevalence of no sport was high (39.7%), being higher in the Portuguese school than in the Brazilian schools (p < 0.001). Irrespective of being an adolescent in a Brazilian or Portuguese school, boys showed higher engagement in sports practice than girls (p < 0.001). In both, differences were identified between adolescents aged 13 to 15 (P = 0.001) and 16 to 17 (P = 0.001). The prevalence of physical inactivity among schoolchildren from two cities in Brazil and a school in Portugal was high, with the girls practicing less sport than the boys and with this imbalance likely to be higher in adolescents.

Objetivos: Avaliar a prevalência de atividade física por meio da prática de esportes em adolescentes de escolas de duas cidades brasileiras e jovens de uma escola portuguesa e sua associação com variáveis independentes, como sexo e idade. Métodos: Estudo transversal realizado em escolares de duas cidades do Brasil e em adolescentes de uma escola duma cidade de Portugal. A amostra total do estudo foi de 3.694 indivíduos (1.622 meninos e 1.872 meninas). O nível de atividade física foi avaliado usando o questionário Baecke. O peso corporal foi medido por meio de uma balança eletrônica e a estatura foi medida com um estadiômetro portátil. As variáveis numéricas foram expressas em média, as variáveis categóricas foram expressas em porcentagens e o teste do qui-quadrado analisou as associações. Resultados: A prevalência de nenhuma prática esportiva foi elevada (39,7%), sendo mais elevada em adolescentes de uma escola portuguesa do que adolescentes das escolas brasileiras (p<0,001). Independente de ser adolescente de escola brasileira ou portuguesa, os meninos apresentaram maior adesão à prática esportiva do que meninas (p<0,001). Em ambos, foram identificadas diferenças entre adolescentes de 13-15 anos (p = 0,001) e 16-17 anos (p = 0,001). Conclusões: A prevalência de inatividade física em escolares de duas cidades do Brasil e em uma escola de uma cidade de Portugal foi elevada. .

[Success in maintaining weight loss in Portugal: the Portuguese Weight Control Registry]. / Sucesso na manutenção do peso perdido em Portugal: o Registo Nacional de Controlo do Peso.

The scope of this article is to describe the Portuguese Weight Control Registry (PWCR) methodology and the participants currently enrolled specifically with respect to their individual and family weight history, previous weight loss attempts, and psychosocial characteristics. One hundred and ninety-eight adults (age: 39.7±11.1 years; BMI: 26.0±3.9 kg/m2), 59% women, filled out a questionnaire about demographics, health-related behaviors and motivation, and methods and strategies used to lose and/or maintain weight loss. Participants reported an average weight loss of 17.4 kg for an average of 29 months. Concerning the number of weight loss attempts, 73% of participants reported a maximum of three attempts of going on a diet, and 34% indicated only one attempt to lose weight in the past. The PWCR now features a considerable number of successful long-term weight loss maintainers in Portugal. Participants will be followed over the next years to learn about their characteristics and weight loss strategies in further detail, as well as to identify predictors of continued weight loss maintenance.

Sucesso na manutencao do peso perdido em Portugal: o Registo Nacional de Controlo do Peso / Success in maintaining weight loss in Portugal: The Portuguese Weight Control Registry

O objetivo deste trabalho é descrever a metodologia do Registo Nacional de Controlo do Peso e descrever os participantes quanto à sua história individual e familiar relacionada com o peso, tentativas anteriores de redução deste e caraterização psicossocial. A amostra inclui 198 adultos (idade: 39,7 ± 11,1anos; IMC: 26,0 ± 3,9kg/m2), 59% mulheres, que completaram um questionário abordando questões demográficas, motivações e atitudes, e estratégias de perda e de manutenção do peso. Os participantes reportaram uma perda do peso média de 17,4kg e uma duração média de manutenção do peso perdido de 29 meses. Relativamente ao número de tentativas de redução do peso reportadas, 73% indicou ter iniciado uma dieta no máximo por três vezes e 34% reportou ter tentado perder peso apenas uma vez no passado. Este estudo irá permitir conhecer com mais detalhe e representatividade as caraterísticas e as estratégias adoptadas por estas pessoas bem sucedidas na manutenção do peso perdido no longo prazo e contribuir para identificar variáveis preditoras da gestão bem sucedida do peso a longo prazo. .

The scope of this article is to describe the Portuguese Weight Control Registry (PWCR) methodology and the participants currently enrolled specifically with respect to their individual and family weight history, previous weight loss attempts, and psychosocial characteristics. One hundred and ninety-eight adults (age: 39.7±11.1 years; BMI: 26.0±3.9 kg/m2), 59% women, filled out a questionnaire about demographics, health-related behaviors and motivation, and methods and strategies used to lose and/or maintain weight loss. Participants reported an average weight loss of 17.4 kg for an average of 29 months. Concerning the number of weight loss attempts, 73% of participants reported a maximum of three attempts of going on a diet, and 34% indicated only one attempt to lose weight in the past. The PWCR now features a considerable number of successful long-term weight loss maintainers in Portugal. Participants will be followed over the next years to learn about their characteristics and weight loss strategies in further detail, as well as to identify predictors of continued weight loss maintenance. .

Determinant factors of cardiorespiratory fitness in Portuguese adolescents of different ethnicities / Fatores Determinantes na aptidão cardiorrespiratória em Portugueses de diferentes etnias

Cardiorespiratory fitness is an important health indicator in young people. The aim of this study was to investigate the effects of age, gender, body adiposity, and ethnicity on cardiorespiratory fitness in a sample of Portuguese adolescents. The sample consisted of 266 adolescents aged 12-18 years [112 boys (80 Caucasians and 32 African-Portuguese, AP) and 154 girls (109 Caucasians and 45 AP)]. Percent body fat was estimated with a hand-to-hand bioelectrical impedance device (BF300, OMROM). Cardiorespiratory fitness was assessed by a shuttle run test (Fitnessgram battery). Multiple regression models were used for statistical analysis. The results showed that girls presented lower maximal oxygen consumption and higher percent body fat than boys. Cardiorespiratory fitness was lower in Caucasian than in AP girls. Multiple regression analysis showed that percent body fat, age and the interaction of age with being Caucasian and age with female gender were significant determinants that were negatively associated with cardiorespiratory fitness. The results suggest that maximal oxygen consumption is lower in adolescents with higher adiposity and in older adolescents. The findings highlight the importance of promoting physical fitness in schools across ages, especially in older adolescents, adjusting for determinant factors such as gender and ethnicity.

A aptidão cardiorrespiratória é um importante indicador de saúde em jovens. O objetivo do presente estudo foi analisar a influência da idade, sexo, adiposidade corporal e etnia na aptidão cardiorrespiratória em uma amostra de adolescentes portugueses. A amostra foi composta por 266 adolescentes, 112 rapazes (80 caucasianos e 32 Afro-Portugueses) e 154 moças (109 caucasianas e 45 Afro-Portuguesas) com idades entre os 12 e 18 anos. Para avaliação da aptidão cardiorrespiratória, foi utilizado o Teste de vai e vem de 20 metros, para a determinação do consumo máximo de oxigénio (VO2max). A impedância bioelétrica (BF300, OMROM) foi utilizada para a estimativa do percentual da massa gorda ( por centoMG). Na análise estatística, foram utilizados modelos de regressão linear múltipla. As adolescentes do sexo feminino apresentaram valores inferiores de VO2max e superiores de por centoMG em comparação aos do sexo masculino. Em relação a etnia, as moças caucasianas apresentaram valores inferiores de VO2max quando comparadas com as afro-portuguesas. O modelo de regressão múltipla demonstrou que o por centoMG, a idade e a interação da idade com ser caucasiano e da idade com ser do sexo feminino foram determinantes significativos, apresentando uma associação negativa com a aptidão cardiorrespiratória. Os resultados sugerem que os adolescentes com maior adiposidade e os mais velhos apresentam um menor consumo máximo de oxigênio. Os dados parecem salientar a importância da promoção da aptidão física nas escolas ao longo da idade, especialmente, os adolescentes mais velhos e adequando a fatores determinantes, como o sexo e a etnia.

Comparing several equations that predict peak VO2 using the 20-m multistage-shuttle run-test in 8-10-year-old children.

This study compared the validity of reported equations as predictors of peak VO(2) in 8-10-year-old children. Participants (90 boys and girls aged 8-10 years) performed the multistage-shuttle-run-test (MSRT) and peak VO(2) was measured in field using a portable gas analyser. The equations that estimated peak VO(2) from the MSRT performance were chosen according to the age range of this study. As follows, the FITNESSGRAM reports and the equations of Leger et al. (Can J Appl Sport Sci 5: 77-84, 1988), Barnett et al. (Pediatr Exerc Sci 5:42-50, 1993), Matsuzaka et al. (Pediatr Exerc Sci 16:113-125, 2004) and Fernhall et al. (Am J Ment Retard 102:602-612, 1998) were used to estimate the peak VO(2) and compared with the directly measured value. The equation of Leger et al. (Can J Appl Sport Sci 5: 77-84, 1988) provided a mean difference (d) of 4.7 ml kg(-1) min(-1) and a 1.0 slope. The equation of Matsuzaka et al. (Pediatr Exerc Sci 16:113-125, 2004)(a) using maximal speed (MS) showed a higher d (5.4) than the remaining using total laps d (4.2). The equation of Barnett et al. (Pediatr Exerc Sci 5:42-50, 1993)(a) that includes triceps skinfold and MS showed the highest d (6.1) but the smallest range (24.1) and slope (0.6). Data from the FITNESSGRAM had the smallest d (1.8 ml kg(-1) min(-1)), but also had the highest range between limits of agreement (28.6 ml kg(-1) min(-1)) and a 1.2 slope. The lowest slope (0.4) and range (22.2 ml kg(-1) min(-1)) were observed using the equation of Fernhall et al. (Am J Ment Retard 102:602-612, 1998). Log transformation of the data revealed that the equations of Matsuzaka et al. (Pediatr Exerc Sci 16:113-125, 2004)(a) (1.1*/÷1.25) and Fernhall et al. (Am J Ment Retard 102:602-612, 1998) (1.17*/÷1.25) showed the closest agreement among all, but they still yield unsatisfactory accuracy.

Magnesium and strength in elite judo athletes according to intracellular water changes.

Magnesium (Mg) deficiency strongly affects muscle performance. In judo, many athletes often undergo impressive weight changes associated with severe dehydration. Common practices used by athletes to achieve a target weight can lead to Mg deficit. This study aimed to understand the impact of Mg changes on strength from periods of weight stability to prior to competition in a sample of elite judo athletes who differentially changed their intracellular water (ICW). The sample consisted of 20 elite male judo athletes. Subjects were divided according to ICW changes: losses below 2% and losses equal to or above 2%. Mg was measured in serum, red blood cells and urine by atomic absorption spectrophotometry. ICW was calculated as the difference between total-body water and extracellular water using dilution techniques. Maximal handgrip strength was evaluated using Jamar Hydraulic Hand Dynamometer. Upper-body power was determined in a bench press. Higher ICW decreases were associated with higher strength reductions, though our results suggest that an increase in red blood cell Mg might attenuate those strength reductions in athletes who decrease the ICW compartment. As Mg losses can be considerable and intake is frequently insufficient, athletes should consider supplementation, especially during periods of weight reduction.

Effect of a 1 year combined aerobic- and weight-training exercise programme on aerobic capacity and ventilatory threshold in patients suffering from coronary artery disease.

Weight-training is recommended as a complement to conventional aerobic-training for most low to moderate risk patients suffering from coronary artery disease (CAD). The purpose of this study was to evaluate the effect of a 1 year exercise programme combining weight- and aerobic-training on peak oxygen uptake (V*O2,peak) and ventilatory threshold (VT). We studied 40 men suffering CAD who were divided into three groups: 14 subjects to weight-training plus aerobic-training [mean (SD] [combined exercise group, age 55 (10) years], 14 to aerobic-training only [aerobic-training group, age 57 (11) years], and 12 to a control group [standard care, age 57 (11) years]. A symptom-limited graded exercise test using the standard Bruce protocol was performed using a 12-lead electrocardiogram, and gas analysis techniques. Muscle strength was determined only in the combined exercise group using the one-repetition maximum method on each of eight weight exercises. Arm and leg strength increased by 21.9% and 27.8% respectively ( P<0.0001) from pre to post-tests. The V*O2,peak did not differ between the combined and aerobic-training groups but their adjusted means were greater than those of the control group [39 (1.8) and 35.3 (1.8) compared to 26.2 (2.7) ml.kg(-1).min(-1) ( P<0.001)]. The oxygen uptake at VT was higher in the combined group [24.7 (1.4) ml.kg(-1).min(-1)] compared to aerobic [18.7 (1.4) ml.kg(-1).min(-1)] and control [13.6 (1.7) ml.kg(-1)min(-1)] groups ( P<0.001). Similar results were found for exercise tolerance (treadmill time to peak and at VT). Combined exercise training increased the VT more than aerobic-training alone. Combined exercise training did not improve the V*O2,peak or the functional capacity more than aerobic-training alone.