Cardiovascular effects of 16 weeks of martial arts training in adolescents / Efeitos cardiovasculares de 16 semanas de treinamento de artes marciais em adolescentes / Efectos cardiovasculares de 16 semanas de entrenamiento de artes marciales en adolescentes

ABSTRACT Introduction: Sedentary habits increase the chances of developing cardiovascular disease. Physical activity is one of the means of prevention and treatment of these diseases, thus martial arts represent a dynamic option in promoting physical activity. Objective: The objective of the study is analyze the effects of 16 weeks of Martial Arts (Muay Thai or judo) training on cardiovascular variables in adolescents. Methods: The sample consisted of 40 adolescents, aged 11 to 14 years, divided into two groups: Martial Arts (n=28) and control (n=12). Weight and height measurements were taken to calculate body mass index. Systolic and diastolic blood pressure (BP), heart rate (HR) at rest, pulse pressure (PP) and rate-pressure product (RPP), were also measured. The intervention was carried out through Martial Arts (Muay Thai and judo) training held twice a week for 90 minutes, over 16 weeks. The control group did not undergo any training. The statistical analysis was performed using the following tests: Shapiro-Wilks, Levene's, analysis of covariance (ANCOVA), eta-squared effect size and the net-effect, using SPSS 15.0 software and a significance level of 5%. Results: There was no statistical difference between the control and Martial Arts groups for the sample characterization. There was a significant difference in systolic BP in the Martial Arts group when compared with the control group (p-value=0.049). The effect size can be considered moderate (effect size=0.163), with a good net-effect (3.4 mmHg). Conclusion: This study showed that 16 weeks of Martial Arts decreased systolic BP in normotensive adolescents. Level of Evidence II; Therapeutic studies - Investigating the results of treatment.

RESUMO Introdução: Os hábitos sedentários aumentam as chances de desenvolvimento de doenças cardiovasculares. A atividade física é um dos meios de prevenção e tratamento dessas doenças, sendo assim, as artes marciais aparecem como uma opção de caráter dinâmico no incentivo à prática de atividades físicas. Objetivos: O objetivo do estudo consiste em analisar os efeitos de 16 semanas de treinamento de artes marciais (Muay Thai ou Judô) sobre as variáveis cardiovasculares nos adolescentes. Métodos: A amostra foi constituída por 40 adolescentes de 11 a 14 anos, divididos em dois grupos: artes marciais (n=28) e controle (n=12). As medições de peso e altura foram realizadas para o cálculo do índice de massa corporal. Foram medidas também a pressão arterial sistólica e diastólica (PA), a frequência cardíaca (FC) em repouso, a pressão de pulso (PP) e o duplo produto (DP). A intervenção foi realizada através da prática de artes marciais (Muay Thai e Judô), realizada duas vezes por semana, durante 90 minutos, por 16 semanas. O grupo controle não realizou nenhum tipo de treinamento. A análise estatística foi feita utilizando os seguintes testes: Shapiro-Wilks, Levene, análise de covariância (ANCOVA), tamanho do efeito eta-squared e efeito líquido, utilizando o software SPSS 15.0 e nível de significância de 5%. Resultados: Não houve diferença estatística entre o grupo controle e o grupo de artes marciais para a caracterização da amostra. Houve diferença significativa na PA sistólica no grupo de artes marciais quando comparado com o grupo controle (valor p=0,049). A dimensão do efeito pode ser considerada moderada (dimensão do efeito=0,163), com um bom efeito líquido (3,4 mmHg). Conclusão: Este estudo demonstrou que 16 semanas de artes marciais diminuíram a PA sistólica em adolescentes normotensos. Nível de Evidência II; Estudos terapêuticos - Investigação dos resultados do tratamento.

RESUMEN Introducción: Los hábitos sedentarios aumentan las posibilidades de desarrollo de enfermedades cardiovasculares. La actividad física es uno de los medios de prevención y tratamiento de esas enfermedades, siendo así, las artes marciales aparecen como una opción de carácter dinámico en el incentivo a la práctica de actividades físicas. Objetivos: El objetivo del estudio es analizar los efectos de 16 semanas de entrenamiento de artes marciales (Muay Thai o Judo) sobre las variables cardiovasculares en adolescentes. Métodos: La muestra fue constituida de 40 adolescentes de 11 a 14 años, divididos en dos grupos: artes marciales (n=28) y control (n=12). Fueron realizadas mediciones de peso y altura para calcular el índice de masa corporal. Fueron medidas también la presión arterial sistólica y diastólica (PA), frecuencia cardíaca (FC) en reposo, la presión de pulso (PP) y el doble producto (DB). La intervención fue realizada a través de la práctica de artes marciales (Judo y Muay Thai), realizada dos veces por semana durante 90 minutos, por 16 semanas. El grupo control no realizó ningún tipo de entrenamiento. El análisis estadístico fue hecho usando los siguientes tests; Shapiro-Wilk, Levene, análisis de covarianza (ANCOVA), tamaño de efecto eta-squared y efecto neto, usando el software SPSS 15.0 y el nivel de significación de 5%. Resultados: No hubo diferencia estadística significativa entre el grupo control y el grupo de artes marciales para la caracterización de la muestra. Hubo diferencia significativa en la PA sistólica en el grupo de artes marciales, cuando comparado con el grupo control ( valor p=0,049). La dimensión del efecto puede ser considerada moderada (dimensión del efecto=0,163) con un buen efecto neto (3,4 mmHg). Conclusión: Este estudio demostró que 16 semanas de artes marciales disminuyeron la PA sistólica en adolescentes normotensos. Nivel de Evidencia II; Estudios terapéuticos - Investigación de los resultados del tratamiento.

Adolescents' physical activity is associated with previous and current physical activity practice by their parents / A atividade física de adolescentes está associada à prática de atividade física anterior e atual por seus pais

Abstract Objective: The purpose of this study was to determine whether parents' current and previous physical activity practice is associated with adolescents' physical activity. Methods: The sample was composed of 1231 adolescents (14-17 years), and 1202 mothers and 871 fathers were interviewed. Weight and height of the adolescents were measured. Self-reported parents' weight and height were obtained. The current and previous physical activity levels (Baecke's questionnaire) of parents (during childhood and adolescence) and adolescents' physical activity levels were obtained using a questionnaire. The magnitude of the associations between parent and adolescent physical activity levels was determined by binary logistic regression (adjusted by sex, age, and socioeconomic level of adolescents and education level of parents). Results: The current physical activity practice by parents was associated with adolescents' physical activity (p < 0.001). The physical activities reported by parents in their childhood and adolescence were also associated with higher physical activity levels among adolescents. Adolescents whose parents were both physically active in the past and present were six times (OR = 6.67 [CI = 1.94-22.79]) more likely to be physically active compared to adolescents with no parents who were physically active in the past. Conclusions: The current and previous physical activities of parents were associated with higher levels of physical activity in adolescents, even after controlling for confounding factors.

Resumo Objetivo: A finalidade deste estudo foi determinar se a prática de atividade física atual e anterior dos pais está associada à atividade física dos adolescentes. Métodos: A mostra foi composta por 1.231 adolescentes (14-17 anos) e foram entrevistados 1.202 mães e 871 pais. Foram medidos o peso e a altura dos adolescentes. Foram obtidos o peso e a altura autorrelatados dos pais. Os níveis de atividade física atual e anterior (questionário de Baecke) dos pais (durante a infância e adolescência) e os níveis de atividade física dos adolescentes foram obtidos com um questionário. A magnitude das associações entre os níveis de atividade física dos pais e adolescentes foi determinada por regressão logística binária (ajustada por sexo, idade e nível socioeconômico dos adolescentes e nível de escolaridade dos pais). Resultados: A prática atual de atividade física pelos pais foi associada à prática de atividade dos adolescentes (p < 0,001). As atividades físicas relatadas pelos pais em sua infância e adolescência também foram associadas aos maiores níveis de atividade física entre os adolescentes. Os adolescentes cujos pais eram fisicamente ativos no passado e atualmente foram seis vezes (RC = 6,67 [IC = 1,94-22,79]) mais propensos a ser fisicamente ativos em comparação com os adolescentes cujos pais não eram fisicamente ativos no passado. Conclusões: As atividades físicas atuais e anteriores dos pais foram associadas aos maiores níveis de atividade física nos adolescentes, mesmo após o controle de fatores de confusão.

Smoking among adolescents is associated with their own characteristics and with parental smoking: cross-sectional study

ABSTRACT BACKGROUND: This study aimed to analyze the association between smoking during adolescence and the characteristics of smoking and alcohol consumption among their parents. DESIGN AND SETTING: Cross-sectional study in Londrina (PR), Brazil. METHODS: The subjects comprised 1,231 adolescents aged 14-17 years. The adolescents and their parents answered a self-report questionnaire that asked for sociodemographic information and data on smoking and alcohol consumption. Multiple logistic regression models were used to analyze associations between smoking among adolescents and their characteristics (age, sex, period of the day for attending school, alcohol consumption and socioeconomic level) and their parents' characteristics (smoking, alcohol consumption, age and education level), adjusted according to the adolescents' characteristics (sex, age and socioeconomic level). RESULTS: The prevalence of smoking among adolescents was 3.4% (95% confidence interval, CI: 2.4-4.4). Adolescents whose mothers or fathers were smokers were 2.0 and 2.5 times more likely to be smokers, respectively. The prevalence of smoking among adolescents with a smoking mother was 7.1% (95% CI: 2.6-10.7) and a smoking father, 5.4% (95% CI: 1.6-8.5). There were significant associations between smoking adolescents and age [5.2% (95% CI: 3.3-6.6)], studying at night [9.6% (95% CI: 4.0-15.5)] and alcohol consumption [69.0% (95% CI: 55.0-83.0)]. It was observed that the number of alcoholic beverage doses consumed was higher among smoking adolescents (P = 0.001). CONCLUSION: Adolescent smoking was associated with smoking by their parents, regardless of the gender of the parents or adolescents. Age, alcohol consumption and studying at night are characteristics of adolescents that can contribute towards smoking.

Relationship between total and segmental bone mineral density and different domains of physical activity among children and adolescents: cross-sectional study

ABSTRACT BACKGROUND: This study aimed to investigate the relationship between total and segmental bone mineral density (BDM) and physical activity (PA) in different domains (school, leisure and sports) among adolescents and children. DESIGN AND SETTING: Cross-sectional study in the Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP). METHODS: The study sample consisted of 173 children and adolescents (10.31 ± 1.87 years). The BMDs for the whole body (WB) and the regions of the trunk and legs were measured using dual energy X-ray absorptiometry (DXA). PA was measured using the Baecke questionnaire. A regression model was used to analyze the relationship between all the BMDs and the different domains of PA. RESULTS: 41.5% of the adolescents had high percentages of body fat. Regarding the comparison between physically active and insufficiently active adolescents, there were no statistically significant differences in any BMD variables (P > 0.05). The BMD of the legs showed positive relationships with the total PA (β = 0.009; P = 0.013) and sports PA (β = 0.010; P = 0.049) after insertion of the confounders. Similarly, the WB BMD showed the same relationships (total PA: β = 0.005; P = 0.045; and sports PA: β = 0.008; P = 0.049). No relationship was found between leisure and school PA and any of the BMDs (P > 0.05). CONCLUSION: The results indicated that practice of sport was related to higher BMD values, independent of sex, age and body fatness.

Can hepatic steatosis compromise the effect of physical exercise on body composition in obese children and adolescents? / Esteatose hepática pode comprometer o efeito do exercício físico sobre a composição corporal em crianças e adolescentes obesos?

Abstract Physical exercise is one of the forms of prevention and treatment of obesity and associated diseases such as hepatic steatosis. The aim of this study was to analyze whether hepatic steatosis interferes in the effect of physical exercise on the body composition of obese children and adolescents. The sample consists of 40 obese individuals, 13 children (8.17±1.33 years) and 27 adolescents (12.28±1.36 years). Total and segmental body composition was estimated by DEXA. Anthropometric measurements were performed, as well as ultrasound examination of the liver to measure intra-abdominal and subcutaneous fat, and to diagnose hepatic steatosis (HS). The intervention consisted of 20 weeks, with recreational/competitive activities being applied to children and, for adolescents, concurrent training (aerobic and resistance). The Levene's, repeated-measures ANOVA and effect size tests (ES) by Eta-Squared were performed. It was observed that, although not statistically significant, analyzing the effect size, physical activity in both children (body fat ES effect time= 0.210 and ES effect group= 0.208; fat mass ES effect group= 0.338; fat android ES effect Interaction= 0.267), and adolescents (intra-abdominal fat ES effect group= 0.230) regardless of whether or not HS was effective in reducing body fat. Therefore, exercise was effective in improving the body composition of obese children and adolescents, regardless of HS.

Resumo O exercício físico é uma das formas de prevenção e tratamento da obesidade e doenças associadas como a esteatose hepática. Objetivou-se analisar se a esteatose hepática interfere no efeito do exercício físico sobre a composição corporal de crianças e adolescentes obesos. A amostra consiste em 40 indivíduos obesos, sendo 13 crianças (8,17±1,33 anos) e 27 adolescentes (12,28±1,36 anos). A composição corporal total e por segmento foi estimada pelo DEXA. Realizou-se medidas antropométricas, bem como, o exame de ultrassom do fígado para mensurar a gordura intra-abdominal e subcutânea, assim, diagnosticar a esteatose hepática (EH). A intervenção foi composta por 20 semanas, sendo aplicadas nas crianças, atividades lúdico-recreativas/competitivas e para os adolescentes, treinamento concorrente (aeróbio e resistido). Foram realizados os testes de Levene, ANOVA de medidas repetidas e o tamanho do efeito (TE) pelo Eta-Squared. Observou-se que, apesar de não obter significância estatística, analisando o tamanho do efeito, o exercício físico tanto nas crianças (gordura corporal TE efeito tempo= 0,210 e TE efeito grupo= 0,208; massa gorda TE efeito grupo= 0,338; gordura andróide TE efeito interação= 0,267), quanto nos adolescentes (gordura intra-abdominal TE efeito grupo=0,230), independentemente se tinham ou não a EH foi eficaz para reduzir a gordura corporal. Observa-se que o exercício físico foi eficaz na melhora da composição corporal de crianças e adolescentes obesos independente da EH.