ABSTRACT
ABSTRACT Objective: Our objective was to perform a systematic review and meta-analysis of the research literature assessing the effect of caffeine on athletic performance. Methods: A total of 13 studies published between 2010 and 2015 were included in the meta-analysis of the effects of caffeine on maximum running distance (2 studies), time trial performance (7 studies), and muscle power (4 studies). The effect sizes were calculated as standardized differences in means (std in means). Meta-analysis was completed using a random effects model. Results: Caffeine supplementation did not increase maximum running distance (effect size= 0.37, p= 0.14) and muscle power (effect size= 0.17, p= 0.36). However, improvements were observed in the time trial performance (effect size= −0.40, p< 0.01). Subgroup analyses revealed that the improvement in time trial results may be related to the use of the 6 mg/kg of body weight of caffeine dose (effect size= −0.45, p= 0.01). Conclusion: Our meta-analysis showed that caffeine intake does not improve performance in maximum running distance and muscle power, but it seems to improve time trial performance. The effect of caffeine on time trial performance related to dose.
RESUMEN Objetivo: Realizar una revisión sistemática y meta-análisis de la literatura de investigación que evalúa el efecto de la cafeína en el rendimiento atlético. Método: Un total de 13 estudios publicados entre 2010 y 2015 fueron incluidos en el meta-análisis de los efectos de la cafeína sobre la distancia máxima de carrera (2 estudios), el tiempo de prueba (7 estudios) y la potencia muscular (4 estudios). Los tamaños del efecto se calcularon como diferencias estandarizadas en las medias (std en los medias), y el meta-análisis se completó utilizando un modelo de efectos aleatorios. Resultados: La suplementación con cafeína no aumentó la distancia máxima de funcionamiento (tamaño del efecto= 0.37, p= 0.14) ni la potencia muscular (tamaño del efecto= 0.17, p= 0.36). Sin embargo, se observaron mejoras en el rendimiento del ensayo con tiempo (tamaño del efecto= −0.40, p< 0,01). Los análisis de subgrupos revelaron que la mejora en los resultados de los ensayos a tiempo podía estar relacionada con el uso de la dosis de 6 mg/kg de peso corporal de cafeína (tamaño del efecto= −0.45, p = 0.01). Conclusiones: El meta-análisis demostró que la ingesta de cafeína no mejora el rendimiento en la distancia máxima de carrera ni la potencia muscular, pero parece mejorar el rendimiento de la prueba de tiempo. Este efecto potencial de la cafeína en el rendimiento de la prueba de tiempo estuvo relacionado con la dosis.
Subject(s)
Humans , Caffeine , Exercise Test , Athletic Performance , Drinking , Energy-Generating Resources/adverse effectsABSTRACT
Introdução: As doenças cardiovasculares representam a maior causa de morte no Brasil e no mundo, sendo a hipertensão arterial sistêmica, um importante fator de risco para seu desenvolvimento. É sugerido que a hipertensão arterial primária inicia-se na infância, podendo agravar com o avançar da idade. Objetivo: Revisar a literatura acerca da prevalência de hipertensão arterial, entre crianças brasileiras em idade escolar. Métodos: Revisão sistemática de trabalhos científicos publicados entre janeiro de 2004 e julho de 2014. A busca foi realizada nas bases de dados Scielo e PubMed, além de pesquisa manual nos artigos presentes nas referências. Os descritores foram: 'hipertensão arterial', pressão arterial alta, 'crianças', 'escolares' e 'Brasil.' Resultados: Foram selecionados 8 artigos pertinentes. A faixa etária dos voluntários dos estudos selecionados variou de 6 a 10 anos de idade. Todos foram realizados em escolas públicas ou privadas e em municípios distintos. A prevalência de hipertensão arterial variou de 2,3% a 13,8%, dependendo do estado nutricional da amostra e da metodologia empregada. Entre os artigos em que a pré-hipertensão foi também avaliada a variação foi de 3,8% a 40,6%. Maiores prevalências foram observadas em crianças com excesso de peso. Conclusão: Os dados apresentados indicaram que a presença de níveis altos de pressão arterial na infância não é rara com prevalências distintas, influenciadas, principalmente, pelo estado nutricional. Novos estudos para avaliar a pressão arterial na infância são necessários a fim de fomentar subsídios para programas de prevenção (AU)
Introduction: Cardiovascular diseases are the leading cause of death in Brazil and in the world, and high blood pressure is an important risk factor for its development. It is suggested that primary hypertension starts in childhood, and it may worse with advancing age. Objective: Review the literature about the prevalence of hypertension among Brazilian school-age children. Methods: Systematic review of cientific studies published from January 2004 to July 2014. The search was conducted in Scielo and PubMed databases, and manual research of articles presented in the references. The used key words were: 'arterial hypertension', 'high blood pressure', 'children', 'school' and 'Brazil.' Results: 8 articles were selected. The volunteers age range was from 6 to 10 years old. All studies were carried out in public or private schools and in different cities. The prevalence of hypertension ranged from 2.3% to 13.8% varying according to nutritional status of the sample and methodology used. In articles that pre-hypertension was also evaluated the range was from 3.8% to 40.6%. Highest prevalence rates were found in children with overweight. Conclusion: The presented data indicate that the presence of high levels of blood pressure in childhood is not rare, with distinct prevalence, influenced mainly by the lifestyle and nutritional status. New studies to evaluate blood pressure in childhood are necessary in order to promote grants for prevention programs (AU)
Subject(s)
Humans , Male , Female , Child , Hypertension/epidemiology , Feeding Behavior , Nutrition Assessment , Nutritional Status , Risk Factors , Brazil/epidemiology , Cross-Sectional StudiesABSTRACT
OBJECTIVE: The purpose of this study was to determine the dietary and anthropometric profiles of the Brazilian amputee soccer players during the training period before the world soccer amputee championship, according to their positional roles in the game. METHODS: Fifteen male athletes participated in the study. Data on height, weight, skinfold thickness, and circumferences were collected to assess nutritional status. Dietary intake was obtained by using 6-d dietary records, analyzed by a Nutrition Support Program for total energy intake, carbohydrates, proteins, lipids, vitamins, and minerals. One-way analysis of variance was used to identify differences in groups (P < 0.05). RESULTS: Midfield players were heavier than the others, and this difference may have been caused by a large quantity of subcutaneous fat. Dietary data showed a low carbohydrate intake and high protein and fat intakes. No athlete met the recommendations for vitamin E, and forward players did not meet recommendations for calcium. CONCLUSION: Amputee athletes need an individualized nutritional orientation and the lack of information about disabled sports and athletes highlights the need for more studies in this area.
