Effects of Resistance Training on Oxidative Stress Markers and Muscle Damage in Spinal Cord Injured Rats.

BACKGROUND: Spinal cord injury (SCI) is a condition that affects the central nervous system, is characterized by motor and sensory impairments, and impacts individuals' lives. The objective of this study was to evaluate the effects of resistance training on oxidative stress and muscle damage in spinal cord injured rats. METHODOLOGY: Forty Wistar rats were selected and divided equally into five groups: Healthy Control (CON), Sham (SHAM) SCI Untrained group (SCI-U), SCI Trained group (SCI- T), SCI Active Trained group (SCI- AT). Animals in the trained groups were submitted to an incomplete SCI at T9. Thereafter, they performed a protocol of resistance training for four weeks. RESULTS: Significant differences in muscle damage markers and oxidative stress in the trained groups, mainly in SCI- AT, were found. On the other hand, SCI- U group presented higher levels of oxidative stress and biomarkers of LDH and AST. CONCLUSION: The results highlight that resistance training promoted a decrease in oxidative stress and a significative response in muscle damage markers.

Dyslipidemia prevalence in adolescents in public schools.

OBJECTIVE: To evaluate the prevalence of dyslipidemia in adolescents enrolled in the state public education system of the city of Montes Claros, state of Minas Gerais, and compare to a Brazilian population-based study. METHOD: This is an epidemiological, cross-sectional, and analytical study with a population of 77,833 students from 63 schools, representing four geographic areas of the city. After a sample calculation, information on 635 adolescents from 10 to 16 years of age was assessed and blood collection was conducted for the analysis of biochemical parameters of total cholesterol, triglycerides, LDL-c, and HDL-c. RESULTS: Among the adolescents, 26.8% showed high levels of total cholesterol, 15.7% of triglycerides, and 6.5% of LDL-c, and 40.8% had low HDL-c levels. CONCLUSION: Except for HDL-c levels, dyslipidemia prevalence and means in adolescents from Montes Claros, Minas Gerais, were above the levels found in the Brazilian population-based study used as parameter.

Dyslipidemia prevalence in adolescents in public schools / Prevalencia de la dislipidemia en adolescentes de la red de enseñanza pública / Prevalência de dislipidemia em adolescentes da rede de ensino pública

ABSTRACT Objective: To evaluate the prevalence of dyslipidemia in adolescents enrolled in the state public education system of the city of Montes Claros, state of Minas Gerais, and compare to a Brazilian population-based study. Method: This is an epidemiological, cross-sectional, and analytical study with a population of 77,833 students from 63 schools, representing four geographic areas of the city. After a sample calculation, information on 635 adolescents from 10 to 16 years of age was assessed and blood collection was conducted for the analysis of biochemical parameters of total cholesterol, triglycerides, LDL-c, and HDL-c. Results: Among the adolescents, 26.8% showed high levels of total cholesterol, 15.7% of triglycerides, and 6.5% of LDL-c, and 40.8% had low HDL-c levels. Conclusion: Except for HDL-c levels, dyslipidemia prevalence and means in adolescents from Montes Claros, Minas Gerais, were above the levels found in the Brazilian population-based study used as parameter.

RESUMEN Objetivo: Evaluar la prevalencia de dislipidemia entre adolescentes matriculados en el sistema público de enseñanza estatal de Monte Claros - Minas Gerais, comparándolo con un estudio de base poblacional brasileño. Método: Estudio epidemiológico transversal y analítico, con población compuesta por 77.833 estudiantes pertenecientes a 63 escuelas correspondientes a las cuatro regiones geográficas municipales. Realizado el cálculo muestral, se analizó la información de 635 adolescentes de 10 a 16 años. Se practicó extracción sanguínea para análisis de parámetros bioquímicos de colesterol total, triglicéridos, LDL-c y HDL-c. Resultados: El 26,8% de los adolescentes mostró valores elevados de colesterol total; el 15,7% tenía los triglicéridos elevados; el 6,5% mostraba valores altos de LDL-c y el 40,8%, niveles bajos de HDL-c. Conclusión: Exceptuando el HDL-c, los promedios y la prevalencia de dislipidemia investigada en adolescentes de Monte Claros - MG fueron superiores a los valores evidenciados en el estudio de base poblacional brasileño utilizado como parámetro.

RESUMO Objetivo: avaliar a prevalência da dislipidemia entre adolescentes matriculados no sistema público de ensino estadual da cidade de Montes Claros - Minas Gerais e comparar com um estudo de base populacional brasileiro. Método: trata-se de um estudo epidemiológico, transversal e analítico, com população composta por 77.833 escolares, oriundos de 63 escolas que representaram quatro regiões geográficas do município. Após o cálculo amostral, foram analisadas informações de 635 adolescentes de 10 a 16 anos e realizada a coleta sanguínea para análise de parâmetros bioquímicos do colesterol total, triglicérides, LDL-c, e HDL-c. Resultados: Entre os adolescentes, 26,8% apresentaram valores elevados de colesterol total, 15,7% de triglicérides, 6,5% de LDL-c e 40,8% níveis baixos de HDL-c. Conclusão: Com exceção do HDL-c, as médias e a prevalência de dislipidemia investigada em adolescentes provenientes de Montes Claros - MG se encontraram acima dos valores evidenciados no estudo de base populacional brasileiro utilizado como parâmetro.

Does Croton Argyrophyllus Extract Has an Effect on Muscle Damage and Lipid Peroxidation in Rats Submitted to High Intensity Strength Exercise?

Many species of the genus Croton have been used for anti-inflammatory, antiproliferative, antidiabetic, and antitumor purposes. The objective was to evaluate the effect of a hydroethanolic extract (HEE) from the inner bark of Croton argyrophyllus (Euphorbiaceae) on muscle damage and oxidative stress in rats after high intensity exercise. The animals were divided into four groups: (i) the sedentary group (SV; n = 7), (ii) the exercise vehicle group (EV, n = 7), (iii) the sedentary group HEE (SHG; n = 7) composed of sedentary animals and treated with the hydroethanolic extract of C. argyrophyllus (200 mg/kg, v.o.), and (iv) the HEE exercise group (HEE; n = 7) composed of animals submitted to resistance exercise (RE) and treated with the hydroethanolic extract of C. argyrophyllus (200 mg/kg, v.o.). In the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) test, the HEE showed lower values of inhibition potential (IP%) at 39.79% compared to gallic acid, 87.61%, and lipoperoxidation inhibition at 27.4% (100 µg/mL) or 28.6% (200 µg/mL) (p < 0.001). There was inhibition in free radicals in vivo. The HEE of C. argyrophyllus partially reduced the biomarkers of oxidative stress in muscle tissue and muscular damage (creatine kinase (CK) and Lactate Dehydrogenase (LDH)) (p < 0.05) in rats, and in this sense it can be an aid to the recovery process after exhaustive efforts.

Insônia: o benefício do exercício físico em adolescentes com excesso de peso / Insomnia: the benefit of physical exercise in overweight teenagers

Introdução: O sono é uma necessidade vital e fisiológica que tem o poder de restauração do organismo e conservação da energia. Entre os adolescentes, notou-se que houve uma diminuição nas horas de sono tornando-os muito vulneráveis à apresentação do quadro de insônia. Objetivo: Verificar níveis de insônia entre adolescentes com excesso de peso antes e depois de um programa de exercício físico. Métodos: Trata-se de um estudo epidemiológico quase experimental e analítico. Na primeira fase do estudo, foram realizados exames laboratoriais, antropométricos, hemodinâmicos e análises nutricionais e psicológicas em 635 adolescentes com idade entre 10 a 16 anos. Destes, 63 adolescentes foram diagnosticados com exceso de peso sendo convidados a participarem de um programa de exercício fisico. Resultados: O grupo-controle evidenciou maior percentual (acima da média) de insônia, tanto no pré (72,7%), quanto no pós teste (90%), e na comparação das médias dos dois grupos, houve uma diferença significativa (p = 0,006). Conclusão: Ressalta-se a significativa diminuição nos níveis de insônia entre os adolescentes que participaram do programa de exercício, propiciando maior bem-estar e disposição para o dia a dia. (AU)

Introduction: Sleep is a vital and physiological necessity that has the power to restore one's organism and to conserve one's energy. Among teenagers, it was noticed that there was a decrease in sleep hours, making them become vulnerable to the insomnia state. Objective: To verify the levels of insomnia among teenagers before and after the participation in a physical exercise program. Methods: This research is an epidemiological study, almost experimental and analytical. In the first stage, there were promoted laboratory exams, anthropometric, hemodynamic, and nutritional and psychological analysis for 635 teenagers aged between 10 to 16 years. Among them, 63 teenagers were diagnosed with overweight and obesity, so they were invited to participate in a physical exercise program. Results: The control group showed a bigger percentage of insomnia (above average), in both the pre-test (72.7%) and in the post-test (90%), and in the average comparison of the two groups there was a significant difference (p = 0.006). Conclusion: A significant decrease of the levels of insomnia among teenagers that participated in the exercise program was noted, providing greater well-being and mood for their daily activities.(AU)

Inclusão do equivalente energético do lactato na regressão VO2-intensidade em corrida horizontal e inclinada (10, 5%) / Inclusion of blood lactate O2 equivalent in the VO2-intensity regression at level and 10.5% grade running

Resumo O estudo teve por objetivo analisar o efeito da adição do equivalente energético do lactato sanguíneo com a medida de VO2 durante a corrida em esteira horizontal (0%) e inclinada (10,5%), como forma de estimativa do custo energético da corrida. Treze corredores de meia e longa distância (idade 28,1 ± 4,2 anos; estatura 1,75 ± 0,07 m; massa corporal 65,2 ± 4,9 kg; VO2max 70,3 ± 4,9 ml·kg-1·min-1) cumpriram dois testes em esteira rolante (0% e 10,5%) que incluíram vários estágios em intensidade constante. Foram calculadas para cada atleta as regressões VO2-velocidade, bem como regressões alternativas com a adição de um equivalente energético de 3 ml O2 Eq·kg-1·mM [La-] às medições de VO2. Não se verificou interação significativa entre a adição do equivalente do lactato e a inclinação da esteira. A ANOVA indicou um efeito significativo da adição do equivalente do lactato na inclinação da reta de regressão e na estimativa do custo energético. Os tamanhos do efeito obtidos indicam que este efeito é mais forte na corrida horizontal. Estes resultados sugerem que em testes laboratoriais com corredores treinados se deverá considerar a adição dos valores de VO2 com os equivalentes energéticos do lactato.(AU)

Abstract This study aimed to analyze the influence of adding blood lactate ([La-]) energy equivalent (Eq) to the VO2 measurements during running exercise at different grades (0% and 10.5%) in order to estimate energy cost of running. Thirteen male highly-trained middle- and long-distance runners (age 28.1 ± 4.2 years; stature 1.75 ± 0.07 m; body mass 65.2 ± 4.9 kg; and maximal oxygen uptake 70.3 ± 4.9 ml·kg-1·min-1) volunteered after medical approval and performed two treadmill tests (0% and 10.5% grade) which included several bouts at a constant speed. Individual VO2-speed regressions were determined for each subject and alternative regressions were established by adding an energy equivalent of 3 ml O2 Eq·kg-1·mM [La-] to the mean VO2 values. No significant interaction between [La-] O2 equivalent inclusion and grade running was found. Results of within-subjects ANOVAs indicated a significant effect of [La-] inclusion in the regression slope and in the estimated energy cost of running at both level and grade running. However, the obtained effect sizes suggest that this effect is considerably higher at level compared with grade running. These findings indicate that the inclusion of [La-] measurements in VO2-intensity regression estimates at sub maximal running should be considered when testing highly trained runners on the treadmill.(AU)

Prevalence of cardiovascular risk factors, the association with socioeconomic variables in adolescents from low-income region / Prevalencia de factores de riesgo cardiovascular, la asociación con las variables socioeconómicas en los adolescentes en región de baja renta

Objectives: To estimate the prevalence of obesity, overweight, abdominal obesity and high blood pressure in a sample of adolescents from a low-income city in Brazil and to estimate the relationship with the socioeconomic status of the family, the education level of the family provider and the type of school. Methods: This cross-sectional study randomly sampled 1,014 adolescents (54.8% girls), between 14-19 years of age, attending high school from Imperatriz (MA). The outcomes of this study were: obesity and overweight, abdominal obesity and high blood pressure (systolic and/ or diastolic). The independent variables were: socioeconomic status (SES) of the family, education level of the family provider (ELFP) and type of school. The confounding variables were: gender, age and physical activity level. Prevalence was estimated, and the association between the endpoints and the independent variables was analyzed using a prevalence ratio (PR), with a 95% confidence interval, estimated by Poisson regression. Results: The overall prevalence of obesity was 3.8%, overweight, 13.1%, abdominal obesity, 22.7% and high blood pressure, 21.3%. The adjusted analysis indicated that girls with high SES showed an increased likelihood to be overweight (PR=1.71 [95% IC: 1.13-2.87]), while private school boys had an increased likelihood of obesity (PR=1.79 [95% CI: 1.04-3.08]) and abdominal obesity (PR =1.64 [95% CI: 1.06-2.54]). Conclusion: The prevalence of CVDR is high in adolescents from this low-income region. Boys from private schools are more likely to have obesity and abdominal obesity, and girls with high SES are more likely to be overweight (AU)

Objetivos: Estimar la prevalencia de obesidad y sobrepeso, obesidad abdominal y hipertensión arterial en una muestra de adolescentes pertenecientes a una ciudad de baja renta en Brasil y su relación con el nivel socioeconómico, nivel educativo de lo responsable de la familia y tipo de escuela. Métodos: Estudio transversal con una muestra de 1014 adolescentes (54,8% chicas), con edades entre 14-19 años, estudiantes de las escuelas de la ciudad de Imperatriz (Brasil), seleccionadas por un muestreo aleatorio. Las variables dependientes evaluadas son: obesidad general y sobrepeso, obesidad abdominal, y tensión arterial alta (sistólica y/o diastólica). Las variables independientes son: nivel socioeconómico de la familia (NSO), el nivel de educación de lo responsable de la familia (NERF) y tipo de escuela. Las variables de confusión son: sexo, edad y nivel de actividad física. La prevalencia fue estimada, y la asociación entre las variables dependientes y las variables independientes se analizaron mediante razón de prevalencia (RP), con intervalo de confianza (IC) del 95%, estimado por la regresión de Poisson. Resultados: La prevalencia de la obesidad general fue de 3,8%, sobrepeso 13,1%, obesidad abdominal 22,7% y la tesión arterial alta 21,3%. Las análisis ajustadas indicaron que las chicas con NSO alto tienen mayor probabilidad de tener sobrepeso (RP=1,71 [IC95%: 1,13 a 2,87]), y chicos de las escuelas privadas tienen más probabilidad de tener obesidad (RP=1,79 [IC95%: 1.04- 3,08]) y obesidad abdominal (RP=1,64 [IC95%: 1,06 a 2,54]). Conclusión: La prevalencia de los FRC es alta en adolescentes de una región de baja renta. Los chicos de las escuelas privadas son más propensos a tener obesidad y obesidad abdominal, y las chicas con NSO alto son más propensas a tener sobrepeso (AU)

Síndrome metabólica e associação com nível socioeconômico em escolares / Metabolic syndrome and its association with socio-economic level in students

Objetivo verificar a associação entre o nível socioeconômico e a presença de síndrome metabólica (SM) em escolares da rede pública da cidade de Montes Claros-MG. Métodos trata-se de estudo transversal, analítico. Foram avaliados 382 escolares entre 10 e 16 anos, a partir da amostragem por conglomerados. A condição socioeconômica foi dividida em alta e baixa e a SM foi diagnosticada utilizando os critérios da International Diabetes Federation. Para análise dos dados, utilizou-se o teste qui-quadrado (p < 0,05)e oddsratio (com intervalo de 95% de confiança). Resultados os escolares da classe socioeconômica baixa apresentaram alterações no estado nutricional e nos exames laboratoriais, o que contribuiu para presença da SM em 8,7% escolares. Conclusão a condição socioeconômica baixa contribui de forma significante para o diagnótico da SM e atua também na incidência dessa patologia, devido os seus pertencentes estarem mais expostos aos fatores de risco. .

Purpose to investigate the association between socioeconomic status and the presence of metabolic syndrome (MS) in public schools in the city of Montes Claros-MG. Methods this is a cross-sectional study, analytical. We evaluated 382 children between 10 and 16 years from the cluster sampling. Socioeconomic status was divided into high and low and MS was diagnosed using the criteria of the International Diabetes Federation. For data analysis, we used the chi-square test (p <0.05) and odds ratios (with 95% confidence). Results the students of lower socioeconomic class showed changes in nutritional status and laboratory tests, which contributed to the presence of MS in 8.7% school. Conclusion the low socioeconomic status contributes significantly to opportune diagnosis of MS and also operates in the incidence of this disease, because their belong ingare more exposed to risk factors. .

Prevalence of cardiovascular risk factors, the association with socioeconomic variables in adolescents from low-income region.

OBJECTIVES: To estimate the prevalence of obesity, overweight, abdominal obesity and high blood pressure in a sample of adolescents from a low-income city in Brazil and to estimate the relationship with the socioeconomic status of the family, the education level of the family provider and the type of school. METHODS: This cross-sectional study randomly sampled 1,014 adolescents (54.8% girls), between 14-19 years of age, attending high school from Imperatriz (MA). The outcomes of this study were: obesity and overweight, abdominal obesity and high blood pressure (systolic and/ or diastolic). The independent variables were: socioeconomic status (SES) of the family, education level of the family provider (ELFP) and type of school. The confounding variables were: gender, age and physical activity level. Prevalence was estimated, and the association between the endpoints and the independent variables was analyzed using a prevalence ratio (PR), with a 95% confidence interval, estimated by Poisson regression. RESULTS: The overall prevalence of obesity was 3.8%, overweight, 13.1%, abdominal obesity, 22.7% and high blood pressure, 21.3%. The adjusted analysis indicated that girls with high SES showed an increased likelihood to be overweight (PR=1.71 [95% IC: 1.13-2.87]), while private school boys had an increased likelihood of obesity (PR=1.79 [95% CI: 1.04-3.08]) and abdominal obesity (PR =1.64 [95% CI: 1.06-2.54]). CONCLUSION: The prevalence of CVDR is high in adolescents from this low-income region. Boys from private schools are more likely to have obesity and abdominal obesity, and girls with high SES are more likely to be overweight.

Objetivos: Estimar la prevalencia de obesidad y sobrepeso, obesidad abdominal y hipertensión arterial en una muestra de adolescentes pertenecientes a una ciudad de baja renta en Brasil y su relación con el nivel socioeconómico, nivel educativo de lo responsable de la familia y tipo de escuela. Métodos: Estudio transversal con una muestra de 1014 adolescentes (54,8% chicas), con edades entre 14-19 años, estudiantes de las escuelas de la ciudad de Imperatriz (Brasil), seleccionadas por un muestreo aleatorio. Las variables dependientes evaluadas son: obesidad general y sobrepeso, obesidad abdominal, y tensión arterial alta (sistólica y/o diastólica). Las variables independientes son: nivel socioeconómico de la familia (NSO), el nivel de educación de lo responsable de la familia (NERF) y tipo de escuela. Las variables de confusión son: sexo, edad y nivel de actividad física. La prevalencia fue estimada, y la asociación entre las variables dependientes y las variables independientes se analizaron mediante razón de prevalencia (RP), con intervalo de confianza (IC) del 95%, estimado por la regresión de Poisson. Resultados: La prevalencia de la obesidad general fue de 3,8%, sobrepeso 13,1%, obesidad abdominal 22,7% y la tesión arterial alta 21,3%. Las análisis ajustadas indicaron que las chicas con NSO alto tienen mayor probabilidad de tener sobrepeso (RP=1,71 [IC95%: 1,13 a 2,87]), y chicos de las escuelas privadas tienen más probabilidad de tener obesidad (RP=1,79 [IC95%: 1.04- 3,08]) y obesidad abdominal (RP=1,64 [IC95%: 1,06 a 2,54]). Conclusión: La prevalencia de los FRC es alta en adolescentes de una región de baja renta. Los chicos de las escuelas privadas son más propensos a tener obesi dad y obesidad abdominal, y las chicas con NSO alto son más propensas a tener sobrepeso.

Relationship between Depression and Strength Training in Survivors of the Ischemic Stroke.

The Cerebral Vascular Accident is responsible for a significant increase in the mortality rate in individuals who have suffered this condition, regardless of the level of subsequent disability. This study aimed to analyze the influence of a strength training program on indicators of depression in survivors of the ischemic stroke. The study sample included subjects from both genders who were divided into two groups: an experimental group (EG) consisting of 11 subjects aged 51.7 8.0 years, and a control group (CG) consisting of 13 subjects aged 52.5 7.7 years. The EG underwent 12 weeks of strength training. Assessment was made in the pre-test before training and at the re-test after 12 weeks of training. We used the Beck Depression Inventory and evaluated 1RM. Significant differences in depression were found between post-test and pretest measurements (Δ% = -21.47%, p = 0,021) in the EG; furthermore, there were significant differences in all indicators of depression between the EG and CG after completing 12 weeks of training. There were significant gains in strength of the EG in relation to the CG. There was a negative correlation between the strength gains as determined with the 1RM test and the levels of depression, especially in lower-limb exercises. The results of this study suggest that improvements in strength are negatively correlated with levels of depression. Improvements in strength are therefore associated with a reduction in levels of depression.

Nutritional Status Associated with Metabolic Syndrome in Middle-School Children in the City of Montes Claros - MG, Brazil.

The aim of this study was to investigate the association between nutritional status and prevalence of metabolic syndrome (MS) in middle-school students in the city of Montes Claros - MG. The sample consisted of 382 students, aged 10-16 years. Nutritional status was evaluated using the Body Mass Index (BMI). Metabolic syndrome (MS) was defined as the presence of two or more criteria in accordance with definition of the International Diabetes Federation. The overall prevalence of MS was 7.9%. 9.7% of students with MS were overweight and 72.4% were obese. Therefore, it can be inferred that carrying excess weight considerably increases the chances for a child to develop MS, and concomitantly increases the child's risk for developing cardiovascular disease.

Inclusão do equivalente do lactato sanguíneo O2 na regressão de intensidade de exercício VO2 aumenta o gasto energético de corrida e diminui sua precisão / Inclusion of blood lactate O2 equivalent in the VO2 exercise intensity regression increases the energy cost of running and lowers its precision / La inclusión del equivalente del lactato sanguíneo O2 en la regresión de intensidad de ejercicio VO2 aumenta el gasto energético de la carrera y disminuye su precisión

INTRODUÇÃO E OBJETIVOS: Investigar se a inclusão do equivalente energético de lactato sanguíneo (LS) em intensidades submáximas alteraria o gasto energético de corrida (Gc) estimado para corrida supramáxima de alta intensidade assim como sua precisão MÉTODOS: O Gc foi determinado a partir da curva de regressão de velocidade do VO2. Para cada sujeito, uma regressão alternativa foi estabelecida em que energia equivalente a 3 ml de O2 kg-1∙mM-1 de LS foi adicionada ao VO2. Testes t pareados, correlações pareadas e plotagem de Bland-Altman foram utilizados para investigar se os dois métodos representam os mesmos fenômenos. RESULTADOS: Os principais achados foram que o Gc previsto para intensidades supramáximas incluídos entre 110 e 160% ao correspondente ao pico de VO2 dos indivíduos aumentou significativamente quando as medidas de LS foram incluídas nas regressões. A inclusão das medidas de LS também aumentaram a imprecisão do Gc a 110, 120, 130, 150 e 160%. CONCLUSÃO: Nossos resultados indicam que a inclusão do equivalente do lactato de O2 na regressão de intensidade de VO2-exercício aumenta o gasto energético e diminui sua precisão.

INTRODUCTION AND OBJECTIVES: Investigate whether the inclusion of the blood lactate (BL) energy equivalent at submaximal intensities would change the energy cost of running (CR) predicted to supramaximal high-intensity running as well as its precision. METHODS: The CR was determined from the slope of the VO2-speed regression. For each subject an alternative regression was established where an energy equivalent of 3 ml O2 kg-1∙mM-1 BL was added to the VO2. Paired t-tests, pairwise correlations and Bland-Altman plots were used to investigate whether the two methods represent the same phenomena. RESULTS: The main findings were that CR predicted to supramaximal intensities comprised between 110% and 160% of that corresponding to the individuals' peak VO2, increased significantly when the BL measurements were included in the regressions. The inclusion of BL measurements also increased the imprecision of the CR at 110%, 120%, 130%, 150% and 160%. CONCLUSIONS: Our results indicate that inclusion of lactate O2 equivalent in the VO2-exercise intensity regression increases the energy cost of running and lowers its precision.

INTRODUCCIÓN Y OBJETIVOS: Investigar si la inclusión del equivalente energético de lactato sanguíneo (LS), en intensidades submáximas, modificaría el gasto energético de la carrera (Gc), estimado para carrera supramáxima de alta intensidad, así como su precisión. MÉTODOS: El Gc fue determinado a partir de la curva de regresión de velocidad del VO2. Para cada individuo, se estableció una regresión alternativa en la cual energía equivalente a 3 ml de O2 kg-1∙mM-1 de LS fue adicionada al VO2. Pruebas t por pares, correlaciones por pares y plotaje de Bland-Altman fueron utilizados para investigar si los dos métodos representan los mismos fenómenos. RESULTADOS: Los hallazgos principales fueron que el Gc previsto para intensidades supramáximas, incluidos 110% y 160% de lo que corresponde al pico de VO2 de los individuos, aumentó significativamente cuando las medidas de LS fueron incluidas en las regresiones. La inclusión de las medidas de LS también aumentó la imprecisión del Gc a 110%, 120%, 130%, 150% y 160%. CONCLUSIÓN: Nuestros resultados indican que la inclusión del equivalente del lactato de O2, en la regresión de intensidad de VO2-ejercicio, aumenta el gasto energético y disminuye su precisión.

Economia de nado: factores determinantes e avaliação / Swimming economy: determinant factors and assessment issues

Economia de nado é um parâmetro importante no controle do processo de treinamento, desde que foi demonstrado que este conceito é relacionado ao desempenho de nado. Economia de nado é afetada por aspectos fisiológicos e biomecânicos, sendo então um conceito que reflete a adaptação de nadadores ao ambiente líquido nesses dois domínios. Uma revisão da literatura sobre economia de nado é apresentada, focalizando alguns dos estudos mais pertinentes que foram publicados sobre este assunto. Diferente dos aspectos biomecânicos e fisiológicos, a economia de nado é influenciada através de outros fatores como: velocidade de nado, habilidade técnica, estado de treinamento, gênero, idade e características antropométricas. Então uma multidão de aspectos estão relacionados com a avaliação da economia de nado e na aplicação deste conceito no controle do processo de treinamento dos nadadores. Uma avaliação apropriada da economia de nado requer a medida direta da captaçãode oxigênio. A escolha do protocolo para avaliar a economia de nado deve ser feita cuidadosamente. Deve ser prestada atenção particular à cinética de captação de oxigênio pelos diferentes níveis de intensidade de exercício. Logo, a intensidade de exercício e duração devem ser consideradas. Em conseqüência a velocidade de nadares tá relacionado intimamente com a velocidade de competição que também é um assunto importante. Embora poucos estudos medissem diretamente a captação de oxigênio de nadadores de alto nível durante a natação, a literatura tem demonstrado que um protocolo descontínuo, com turnos de exercício crescentes de duração entre três e seis minutos parecem apropriados para avaliar a economia de nado.

Swimming economy is an important parameter in the control of the training process, since it has been demonstrated that this concept is related to the swimming performance. Swimming economy is affected by physiological and biomechanical constraints, therefore being a concept that reflects the swimmers´ adaptation to the liquid environment in those two domains. A review of the literature about swimming economy is presented, focusing some of the most relevant studies that have been conducted on this issue. Other than the biomechanical and physiological constraints, the swimming economy is influenced by other factors such as: swimming velocity, technical ability, training status, gender, age and anthropometric characteristics. Therefore a multitude of aspects are pertinent in the assessment of swimming economy and in the application of this concept in the control of the swimmers' training process. A proper assessment of the swimming economy requires the direct measurement of the oxygen uptake. The choice of the protocol to assess the swimming economy must be carefully done. Particular attention must be paid to the oxygen uptake kinetics across the different levels of exercise intensity. Therefore, both exercise intensity and duration are to be considered. The attainment of swimming velocities as close as possible to the competition velocity is also an important issue. Although few studies have measured directly the oxygen uptake of top-level performers during swimming, the literature shows that a discontinuous protocol, with increasing exercise bouts of duration between three and six minutes seem appropriate to assess the swimming economy.

Relação entre a prestação no salto em comprimento e no triplo salto e o desempenho em testes de corrida, impulsão e força isométrica / Relationship between long jump and triple jump distance and the performance in running, jumping and strength tests

A aplicação de baterias de testes é o meio mais usual para avaliar o estado de forma de atletas de diversas especialidades. Assim sucede com os especialistas de saltos horizontais (salto em comprimento e triplo salto). O objectivo do presente estudo foi investigar a relação entre a prestação no Salto em Comprimento e no Triplo Salto e o desempenho em testes de corrida, impulsão e força isométrica. Quarenta e cinco estudantes de educação física do sexo masculino realizaram duas competições, uma de salto em comprimento e outra de triplo salto. Na semana seguinte foram submetidos aos seguintes testes: 1) 20 m de corrida com balanço prévio (20m);2) impulsão horizontal a pés juntos; 3) triplo salto com apoios alternados e partida parada (TS); 4) teste de força máxima isométrica e de força média isométrica; 5) Squat Jump; 6) Counter Movement Jump; 7) Drop Jump. Os testes de 20m e de TS foram os que demonstraram maior grau de associação com a prestação competitiva nos saltos horizontais e permitiram, em conjunto, explicar cerca de 50% da variância do resultado no triplo salto e nos alto em comprimento. Concluímos que os testes de 20m e de TS podem ser usados para predizer a prestação de iniciantes no salto em comprimento e no triplo salto com um erro de predição da prestação aceitável (¼6% e¼4%, respectivamente). Os resultados também sugerem que testes de terreno de corrida e de impulsão horizontal são preferíveis aos testes de laboratório para avaliar a aptidão de saltadores...

The use of test batteries is the most common procedure to assess the specific preparation status of athletes. This procedure is also observed in the case of horizontal jumpers (long and triple jump). The aim of the present study was to investigate the associations between the performance in the long jump and in the triple jump and the performance in running, jumping and strength tests. Forty-five male physical education students performed competitions in long jump and triple jump after a month of technique learning. A week later, they were submitted to the following tests: 1) 20 m maximum-speed running (20m); 2) standing long jump; 3) standing triple jump with alternate legs (TS); 4) maximum and mean isometric strength; 5) Squat Jump; 6) Counter Movement Jump; 7)Drop Jump. The 20m and the TS were the tests that showed a larger association with the competitive performance in the horizontal jumps and, altogether, they were able to explain about 50% of the variance of the results in the long jump and in the triple jump. We conclude that the 20m and the TS can be used to predict the performance of novices in the long jump and in the triple jump with an acceptable error (¼6% e ¼4%, respectively). The results also suggest that running and horizontal jumping field tests are preferable than laboratory tests to assess the jumpers fitness...