Katiuce Borges Sapata

Effect of biological maturation on maximal oxygen uptake and ventilatory thresholds in soccer players: An allometric approach

Abstract In this study, we investigated the effect of biological maturation on maximal oxygen uptake ([Vdot]O2max) and ventilatory thresholds (VT1 and VT2) in 110 young soccer players separated into pubescent and post-pubescent groups.. Maximal oxygen uptake and [Vdot]O2 corresponding to VT1 and VT2 were expressed as absolute values, ratio standards, theoretical exponents, and experimentally observed exponents. Absolute [Vdot]O2 (ml · min−1) was different between groups for VT1, VT2, and [Vdot]O2max. Ratio standards (ml · kg−1 · min−1) were not significantly different between groups for VT1, VT2, and [Vdot]O2max. Theoretical exponents (ml · kg−0.67 · min−1 and ml · kg−0.75 · min−1) were not properly adjusted for the body mass effects on VT1, VT2, and [Vdot]O2max. When the data were correctly adjusted using experimentally observed exponents, VT1 (ml · kg−0.94 · min−1) and VT2 (ml · kg−0.95 · min−1) were not different between groups. The experimentally observed exponent for [Vdot]O2max (ml · kg−0.90 · min−1) was different between groups (P = 0.048); however, this difference could not be attributed to biological maturation. In conclusion, biological maturation had no effect on VT1, VT2 or [Vdot]O2max when the effect of body mass was adjusted by experimentally observed exponents. Thus, when evaluating the physiological performance of young soccer players, allometric scaling needs to be taken into account instead of using theoretical approaches.

Efeitos do consumo prévio de carboidratos sobre a resposta glicêmica e desempenho

Bases and Objective: Nutrition is an important tool for the sport practice. Among the nutrients, the carbohydrates are one of the most important. In that way the aim of this study was analyze the influence of glycaemic response on performance of healthy subjects, after intake of different carbohydrate solutions. Methods: Ten healthy male subjects, 23 ± 2.1 years old, were asked to answer a three days nutritional and physical activity recordatory. Anthropometric data were collected and a progressive test in cycle ergometer was performed to measure the maximal oxygen uptake and ventilatory thresholds. Each subject performed three submaximal tests at the intensity of second ventilatory threshold. Thirty minutes before each submaximal test, 250 ml of each drink: maltodextrin (Malto), glucose (Glicose) plus sport drink or dietetic juice (Placebo) was ingested. Venous blood was collected to determine the glycaemic index and lactate. Results and Conclusion: There was a significant increase after 30 minutes when the subjects ingested maltodextrin solution (87.4 ± 11.2 to 116.9 ± 19.6 ml.dl -1). After 15 minutes of exercise, there was a decrease in the glycaemia after the consumption of Malto (116.9 ± 19.6 to 77.6 ± 14.5 ml.dl -1) and Glicose (113.2 ± 23.5 to 81.8 ± 13.1 ml.dl -1) plus sport drink solutions when compared with Placebo solution. The glucose plus sport drink solution induced a significant increase in the heart rate during exercise (167.7 ± 14.2 and 177.1 ± 10.4 bpm). The consumption of different carbohydrate solutions with high glycaemic index before exercise was not capable to change the performance of the volunteers. However it induced changes in the glycaemia and heart rate during exercise. Thus the oscillations on glycaemia during exercise may affect negatively the long distance performance, this fact was not verified in our study.INTRODUCAO E OBJETIVO: A nutricao e uma importante ferramenta dentro da pratica desportiva. Dentre os nutrientes, os carboidratos destacam-se como uma fonte energetica importante. Dessa forma, o objetivo deste trabalho foi verificar a influencia da resposta glicemica no desempenho de individuos saudaveis, apos a ingestao de bebidas com diferentes tipos de carboidratos. METODOS: Foram avaliados 10 voluntarios, do sexo masculino, com idade de 23 ± 2,1 anos. Os voluntarios preencheram recordatorio alimentar de tres dias e de atividade fisica. Foram realizadas avaliacoes antropometricas e teste de cargas progressivas em cicloergometro para determinacao do consumo maximo de oxigenio e limiares ventilatorios. Cada voluntario realizou tres testes submaximos na intensidade do 2o limiar ventilatorio. Trinta minutos antes de cada teste submaximo, foram ingeridos 250ml de uma das bebidas compostas por: maltodextrina (malto), glicose (glicose), ou suco dietetico (placebo). Foram realizadas puncoes de sangue capilar para determinacao dos niveis glicemicos e lactato sanguineo. RESULTADOS E CONCLUSAO: Houve aumento significativo na glicemia apos 30 minutos do consumo da bebida malto (87,4 ± 11,2 para 116,9 ± 19,6ml.dl1). Aos 15 minutos do exercicio, houve diminuicao nos niveis glicemicos apos o consumo das bebidas malto (116,9 ± 19,6 para 77,6 ± 14,5ml.dl1) e glicose (113,2 ± 23,5 para 81,8 ± 13,1ml.dl1) em comparacao com o placebo. A ingestao da bebida glicose provocou aumento significativo na frequencia cardiaca durante o exercicio (167,7 ± 14,2 e 177,1 ± 10,4bpm). O consumo de bebidas com diferentes tipos de carboidratos e de alto indice glicemico antes do exercicio nao foi capaz de alterar o desempenho dos voluntarios; entretanto, ocasionou alteracoes na glicemia e na frequencia cardiaca durante o exercicio. Embora se especule que oscilacoes na glicemia durante o exercicio possam prejudicar o desempenho em exercicios de longa duracao, esse fato nao foi verificado em nosso estudo.

Efeito da suplementação de L-arginina sobre a secreção de hormônio do crescimento e fator de crescimento semelhante à insulina em adultos

Based on presumptions that the infusion of amino acids can augment the release of human growth hormone (hGH) and that this metabolism is related with secretion of insulin-like growth factor I (IGF-I), the purpose of this study was to verify the effect of L-arginine supplementation on GH and IGF-I in adults. Seventeen male individuals participated on the study and were randomized to receive L-arginine (n= 10) or placebo (n= 7), seven grams per day for seven days. Before and after the supplementation period, the volunteers realized blood collection in fasting to verify both GH and IGF-I levels, as well as urine collection to verify urea excretion. At the end of the experimental period, it was verified that the group that received L-arginine augmented the urea in urine excretion (to 2684.1 ± 475.2 mg/dl from 2967.2 ± 409.7 mg/dl, p= 0.002), therefore it did not alter significantly the release of hormones evaluated. The group which received placebo did not alter significantly any evaluated parameters. The L-arginine supplementation during seven days was ineffective to augment both GH and IGF-I release in individual male adults.

Efeitos da ingestão prévia de carboidrato de alto índice glicêmico sobre a resposta glicêmica e desempenho durante um treino de força

The aim of this study was to examine the effects of pre-exercise carbohydrate ingestion on performance and glycemic response during a strength training session. Eight male volunteers performed 2 strength exercise sessions with the ingestion of a carbohydrate (maltodextrin) or placebo drink 15 minutes before each session (7 exercises with 3 sets at 70% of 1 maximum repetition). The trials were performed 7 days apart from each other and their order was randomized. Glycemia was measured at 4 times: before the drink ingestion, 15 minutes after the drink ingestion, halfway through the training and at the end of the exercise session. The total performance was affected by variation on achieved repetitions in the different days, which were inserted in the total load rate analysis performed in the respective sessions (repetitions · sets · load). Heart rate was continuously monitored and lactate concentration was measured at the end of session. Glycemia increased only at 15 minutes after the carbohydrate drink ingestion (from 98.25 ± 17.77mg/dL to 133.12±22.76 mg/dL, p= 0.015) , while on the placebo drink day no significant changes were observed (from 98.25 ± 13.69 mg/dL to 94.38 ± 12.21 mg/dL, p=1.000). The total load rate, heart rate and final lactate concentration were not different in the two strength exercise sessions. Although pre-exercise glycemia was increased after the carbohydrate drink ingestion, the results do not indicate that carbohydrate ingestion before strength exercise session can be an efficient supplementation in order to improve physical performance.

Effect of prior consumption of carbohydrate on the glycaemia and performance

Bases and Objective: Nutrition is an important tool for the sport practice. Among the nutrients, the carbohydrates are one of the most important. In that way the aim of this study was analyze the influence of glycaemic response on performance of healthy subjects, after intake of different carbohydrate solutions. Methods: Ten healthy male subjects, 23 ± 2.1 years old, were asked to answer a three days nutritional and physical activity recordatory. Anthropometric data were collected and a progressive test in cycle ergometer was performed to measure the maximal oxygen uptake and ventilatory thresholds. Each subject performed three submaximal tests at the intensity of second ventilatory threshold. Thirty minutes before each submaximal test, 250 ml of each drink: maltodextrin (Malto), glucose (Glicose) plus sport drink or dietetic juice (Placebo) was ingested. Venous blood was collected to determine the glycaemic index and lactate. Results and Conclusion: There was a significant increase after 30 minutes when the subjects ingested maltodextrin solution (87.4 ± 11.2 to 116.9 ± 19.6 ml.dl -1). After 15 minutes of exercise, there was a decrease in the glycaemia after the consumption of Malto (116.9 ± 19.6 to 77.6 ± 14.5 ml.dl -1) and Glicose (113.2 ± 23.5 to 81.8 ± 13.1 ml.dl -1) plus sport drink solutions when compared with Placebo solution. The glucose plus sport drink solution induced a significant increase in the heart rate during exercise (167.7 ± 14.2 and 177.1 ± 10.4 bpm). The consumption of different carbohydrate solutions with high glycaemic index before exercise was not capable to change the performance of the volunteers. However it induced changes in the glycaemia and heart rate during exercise. Thus the oscillations on glycaemia during exercise may affect negatively the long distance performance, this fact was not verified in our study.INTRODUCAO E OBJETIVO: A nutricao e uma importante ferramenta dentro da pratica desportiva. Dentre os nutrientes, os carboidratos destacam-se como uma fonte energetica importante. Dessa forma, o objetivo deste trabalho foi verificar a influencia da resposta glicemica no desempenho de individuos saudaveis, apos a ingestao de bebidas com diferentes tipos de carboidratos. METODOS: Foram avaliados 10 voluntarios, do sexo masculino, com idade de 23 ± 2,1 anos. Os voluntarios preencheram recordatorio alimentar de tres dias e de atividade fisica. Foram realizadas avaliacoes antropometricas e teste de cargas progressivas em cicloergometro para determinacao do consumo maximo de oxigenio e limiares ventilatorios. Cada voluntario realizou tres testes submaximos na intensidade do 2o limiar ventilatorio. Trinta minutos antes de cada teste submaximo, foram ingeridos 250ml de uma das bebidas compostas por: maltodextrina (malto), glicose (glicose), ou suco dietetico (placebo). Foram realizadas puncoes de sangue capilar para determinacao dos niveis glicemicos e lactato sanguineo. RESULTADOS E CONCLUSAO: Houve aumento significativo na glicemia apos 30 minutos do consumo da bebida malto (87,4 ± 11,2 para 116,9 ± 19,6ml.dl1). Aos 15 minutos do exercicio, houve diminuicao nos niveis glicemicos apos o consumo das bebidas malto (116,9 ± 19,6 para 77,6 ± 14,5ml.dl1) e glicose (113,2 ± 23,5 para 81,8 ± 13,1ml.dl1) em comparacao com o placebo. A ingestao da bebida glicose provocou aumento significativo na frequencia cardiaca durante o exercicio (167,7 ± 14,2 e 177,1 ± 10,4bpm). O consumo de bebidas com diferentes tipos de carboidratos e de alto indice glicemico antes do exercicio nao foi capaz de alterar o desempenho dos voluntarios; entretanto, ocasionou alteracoes na glicemia e na frequencia cardiaca durante o exercicio. Embora se especule que oscilacoes na glicemia durante o exercicio possam prejudicar o desempenho em exercicios de longa duracao, esse fato nao foi verificado em nosso estudo.

Efectos del consumo previo de carbohidratos sobre la respuesta de glicemia y desempeño

Bases and Objective: Nutrition is an important tool for the sport practice. Among the nutrients, the carbohydrates are one of the most important. In that way the aim of this study was analyze the influence of glycaemic response on performance of healthy subjects, after intake of different carbohydrate solutions. Methods: Ten healthy male subjects, 23 ± 2.1 years old, were asked to answer a three days nutritional and physical activity recordatory. Anthropometric data were collected and a progressive test in cycle ergometer was performed to measure the maximal oxygen uptake and ventilatory thresholds. Each subject performed three submaximal tests at the intensity of second ventilatory threshold. Thirty minutes before each submaximal test, 250 ml of each drink: maltodextrin (Malto), glucose (Glicose) plus sport drink or dietetic juice (Placebo) was ingested. Venous blood was collected to determine the glycaemic index and lactate. Results and Conclusion: There was a significant increase after 30 minutes when the subjects ingested maltodextrin solution (87.4 ± 11.2 to 116.9 ± 19.6 ml.dl -1). After 15 minutes of exercise, there was a decrease in the glycaemia after the consumption of Malto (116.9 ± 19.6 to 77.6 ± 14.5 ml.dl -1) and Glicose (113.2 ± 23.5 to 81.8 ± 13.1 ml.dl -1) plus sport drink solutions when compared with Placebo solution. The glucose plus sport drink solution induced a significant increase in the heart rate during exercise (167.7 ± 14.2 and 177.1 ± 10.4 bpm). The consumption of different carbohydrate solutions with high glycaemic index before exercise was not capable to change the performance of the volunteers. However it induced changes in the glycaemia and heart rate during exercise. Thus the oscillations on glycaemia during exercise may affect negatively the long distance performance, this fact was not verified in our study.INTRODUCAO E OBJETIVO: A nutricao e uma importante ferramenta dentro da pratica desportiva. Dentre os nutrientes, os carboidratos destacam-se como uma fonte energetica importante. Dessa forma, o objetivo deste trabalho foi verificar a influencia da resposta glicemica no desempenho de individuos saudaveis, apos a ingestao de bebidas com diferentes tipos de carboidratos. METODOS: Foram avaliados 10 voluntarios, do sexo masculino, com idade de 23 ± 2,1 anos. Os voluntarios preencheram recordatorio alimentar de tres dias e de atividade fisica. Foram realizadas avaliacoes antropometricas e teste de cargas progressivas em cicloergometro para determinacao do consumo maximo de oxigenio e limiares ventilatorios. Cada voluntario realizou tres testes submaximos na intensidade do 2o limiar ventilatorio. Trinta minutos antes de cada teste submaximo, foram ingeridos 250ml de uma das bebidas compostas por: maltodextrina (malto), glicose (glicose), ou suco dietetico (placebo). Foram realizadas puncoes de sangue capilar para determinacao dos niveis glicemicos e lactato sanguineo. RESULTADOS E CONCLUSAO: Houve aumento significativo na glicemia apos 30 minutos do consumo da bebida malto (87,4 ± 11,2 para 116,9 ± 19,6ml.dl1). Aos 15 minutos do exercicio, houve diminuicao nos niveis glicemicos apos o consumo das bebidas malto (116,9 ± 19,6 para 77,6 ± 14,5ml.dl1) e glicose (113,2 ± 23,5 para 81,8 ± 13,1ml.dl1) em comparacao com o placebo. A ingestao da bebida glicose provocou aumento significativo na frequencia cardiaca durante o exercicio (167,7 ± 14,2 e 177,1 ± 10,4bpm). O consumo de bebidas com diferentes tipos de carboidratos e de alto indice glicemico antes do exercicio nao foi capaz de alterar o desempenho dos voluntarios; entretanto, ocasionou alteracoes na glicemia e na frequencia cardiaca durante o exercicio. Embora se especule que oscilacoes na glicemia durante o exercicio possam prejudicar o desempenho em exercicios de longa duracao, esse fato nao foi verificado em nosso estudo.