Comparison between critical speed and maximal lactate steady state in amateur distance runners

The purpose of this study was to compare maximal lactate steady state (MLSS) and the critical speed (CS) in distance runners. Six male athletes were submitted to the CS test, to linear regression of the distances (800, 1.500, 3.000 and 5.000m). The CS was determined by the angular coefficient of the linear regression (Distance x Time). The predicted workloads for the MLSS determination were: 103; 100 and 98% of the CS, randomized and in a continuous way in subsequent days. In MLSS test, the athletes run for 30 min, and it was collected blood samples (25μL) at 10th and 30th min, to determine the lactate concentration (YSI 1500 sport). It was determined MLSS the non lactate variation higher than 1.0 mmol/L between the 10th and 30th minute. The MLSS occurred for 5 athletes on the 100% intensity of CS (15.1 ± 1.5 Km/h) and for 1 athlete on the 95% (14.3 Km/h). At 100% of CS, the MLSS concentration was: rest lactate (RL)= 1.0 ± 0.3 mmol/L; 10thmin= 3.28 ± 0.64; 30th 3.92 ± 1.14. At 103% of CS, the MLSS concentration was: RL= 1.10 ± 0.41 mmol/L; 10thmin= 3.06 ± 1.44; 30th 4.12 ± 1.59. The MLSS occurred at 100% of MLSS. These results showed that the CS is a trustful test to predict the MLSS in distance runners with MLSS velocity at 15Km/h

Influence of the pedaling cadence in determining the critical power in the cycloergometer

The objective of this study was to determine the critical power (PCrit) using intensities of 230, 250, 270 and 300 Watts (W) under different speeds ranging from pedaling (60 and 80 rotations per minute - rpm). Two young adults, male, healthy and active, with an average age 22 years were selected. The test was conducted in cycle model Monark® ergomedic 894 E. The depth charges were chosen randomly, changing the relationship load and speed from the cadence. The exhaustion criterion was the voluntary withdrawal or failure to maintain the speed for 5 seconds. To determine the PCrit and anaerobic work capacity (CTA) the linear model of power 1/tempo x exhaustion was used. The results are expressed as mean ± standard deviation of the mean. The t Student test for independent samples for comparison PCrit CTA and the cadences of 60 and 80 rpm was used. During the tests the heart rate (bpm) every 15 seconds was recorded. The results of PCrit to 60 rpm (Pcrit60rpm) and PCrit at 80 rpm (Pcrit80rpm) were not statistically different (Pcrit60rpm=208.1±12.0 W and Pcrit80rpm=165.5±33.2 W). The average Pcrit60rpm was 25% higher than Pcrit80rpm. The absolute values of CTA were not different (CTA60rpm=10316.6±3766.7, CTA80rpm=15996.5±5247.4). The CTA80rpm was 55% higher compared to CTA60rpm. Thus, one can conclude that the cadence of pedaling at 60 rpm and 80 did not statistically influence the values of PCrit and CAT. However, the percentage of Pcrit80rpm was significantly below Pcrit60rpm

The effects of acute exercise on serum biomarkers in diabetics rats

INTRODUÇÃO: As respostas ao exercício agudo dos biomarcadores, como a fosfatase alcalina (FA) e a creatina quinase (CK) séricas têm sido pouco investigadas em ratos diabéticos. OBJETIVOS: Verificar os efeitos do exercício físico aeróbio agudo sobre as concentrações de CK e FA, bem como, avaliar o estado hídrico em ratos diabéticos experimentais. MATERIAIS E MÉTODOS: Foram utilizados ratos Wistar machos, adultos jovens, distribuídos em dois grupos: diabéticos (DA) e controles (CA). O diabetes foi induzido por meio da administração de aloxana monoidratado Sigma(r) (32 mg/kg de peso corporal). Duas semanas após confirmação do diabetes, ambos os grupos foram submetidos a uma sessão aguda de natação por 30 min, com carga aeróbia (4,5 % do peso corporal). Foram avaliados: glicose, hematócrito, CK, FA, albumina e a cinética de lactato durante o exercício por meio de coletas 25 µL de sangue da cauda dos animais, nos minutos 0, 10, 20 e 30 de exercício. RESULTADOS: ANOVA de dois fatores para medidas repetidas e o teste post hoc de Tukey apontaram diminuição significativa dos valores de glicemia após o exercício para o grupo DA, aumento significativo de CK pós-exercício para o grupo DA, aumento significativo de hematócrito para ambos os grupos após exercício e manutenção da FA após exercício para o grupo DA. CONCLUSÃO: O exercício agudo aeróbio foi eficiente no controle dos níveis glicêmicos de ratos diabéticos. Entretanto, deve ser aplicado com cautela, pois induziu altos valores de CK, sugerindo possíveis lesões teciduais2013235INTRODUCTION: The responses to acute exercise on biomarkers, such as alkaline phosphatase (ALP) and creatine kinase (CK) serum levels have been little investigated in diabetic rats. OBJECTIVES: To investigate the effects of acute aerobic exercise on the concentrations of CK and ALP as well as evaluating the hydration status in diabetic rats. MATERIALS AND METHODS: Were used male Wistar rats, young adults, divided into two groups: diabetic (DA) and controls (CA). The diabetes was induced in the rats by administration of alloxan monohydrate Sigma(r) (32 mg/kg body weight). Two weeks after confirmation of diabetes, both groups were subjected to an acute swim session for 30 min, with aerobic load (4.5% body weight). Glucose, hematocrit, CK, ALP, albumin and lactate kinetics during exercise were evaluated by collecting 25µL of blood from the tail of the animals in minutes 0, 10, 20 and 30 of exercise. RESULTS: Two-way ANOVA for repeated measures and post hoc Tukey test showed significant decrease of glycemia after exercise for the DA group, significant increase in CK after exercise for the DA group, significant increase in hematocrit for both groups after exercise and maintenance of ALP after exercise for the DA group. CONCLUSION: The acute aerobic exercise was effective in controlling glucose levels in diabetic rats. However, it should be applied with caution, because it induced high CK values, suggesting possible tissue damagesem informaçã

Efeitos do exercicio agudo sobre biomarcadores sericos de ratos diabeticos

INTRODUÇÃO:As respostas ao exercício agudo dos biomarcadores, como a fosfatase alcalina (FA) e a creatina quinase (CK) séricas têm sido pouco investigadas em ratos diabéticos.OBJETIVOS:Verificar os efeitos do exercício físico aeróbio agudo sobre as concentrações de CK e FA, bem como, avaliar o estado hídrico em ratos diabéticos experimentais.MATERIAIS E MÉTODOSForam utilizados ratos Wistar machos, adultos jovens, distribuídos em dois grupos: diabéticos (DA) e controles (CA). O diabetes foi induzido por meio da administração de aloxana monoidratado Sigma(r) (32 mg/kg de peso corporal). Duas semanas após confirmação do diabetes, ambos os grupos foram submetidos a uma sessão aguda de natação por 30 min, com carga aeróbia (4,5 % do peso corporal). Foram avaliados: glicose, hematócrito, CK, FA, albumina e a cinética de lactato durante o exercício por meio de coletas 25 µL de sangue da cauda dos animais, nos minutos 0, 10, 20 e 30 de exercício.RESULTADOS:ANOVA de dois fatores para medidas repetidas e o teste post hoc de Tukey apontaram diminuição significativa dos valores de glicemia após o exercício para o grupo DA, aumento significativo de CK pós-exercício para o grupo DA, aumento significativo de hematócrito para ambos os grupos após exercício e manutenção da FA após exercício para o grupo DA.CONCLUSÃO:O exercício agudo aeróbio foi eficiente no controle dos níveis glicêmicos de ratos diabéticos. Entretanto, deve ser aplicado com cautela, pois induziu altos valores de CK, sugerindo possíveis lesões teciduais.INTRODUCCIÓN:Las respuestas al ejercicio agudo de los biomarcadores, como la fosfatasa alcalina (FA) y la creatina quinasa (CK) séricas han sido poco investigadas en ratones diabéticos.OBJETIVOS:Verificar los efectos del ejercicio físico aeróbico agudo sobre las concentraciones de CK y FA, bien como evaluar el estado hídrico en ratones diabéticos experimentales.MATERIALES Y MÉTODOS:Fueron utilizados ratones Wistar machos, adultos jóvenes, distribuidos en dos grupos: diabéticos (DA) y controles (CA). La diabetes fue inducida por medio de la administración de aloxana monohidratado Sigma(r) (32 mg/kg de peso corporal). Dos semanas después de la confirmación de la diabetes, ambos grupos fueron sometidos a una sesión aguda de natación por 30 minutos, con carga aeróbica (4,5% del peso corporal). Fueron evaluados: Glucosa, hematocrito, CK, FA, albumina y La cinética de lactato durante el ejercicio por medio de colectas de 25 µL de sangre de la cola de los animales, en los minutos 0, 10, 20 y 30 de ejercicio.RESULTADOS:ANOVA de dos factores para medidas repetidas y el test post hoc de Tukey apuntaron disminución significativa de los valores de glicemia después del ejercicio para el grupo DA, aumento significativo de CK después del ejercicio para el grupo DA, aumento significativo de hematocrito para ambos grupos después del ejercicio y mantenimiento de la FA después del ejercicio para el grupo DA.CONCLUSIÓN:El ejercicio agudo aeróbico fue eficiente en el control de los niveles glicémicos de ratones diabéticos. Entretanto, debe ser aplicado con cautela, pues indujo altos valores de CK, sugiriendo posibles lesiones tisulares.INTRODUCTION:The responses to acute exercise on biomarkers, such as alkaline phosphatase (ALP) and creatine kinase (CK) serum levels have been little investigated in diabetic rats.OBJECTIVES:To investigate the effects of acute aerobic exercise on the concentrations of CK and ALP as well as evaluating the hydration status in diabetic rats.MATERIALS AND METHODS:Were used male Wistar rats, young adults, divided into two groups: diabetic (DA) and controls (CA). The diabetes was induced in the rats by administration of alloxan monohydrate Sigma(r) (32 mg/kg body weight). Two weeks after confirmation of diabetes, both groups were subjected to an acute swim session for 30 min, with aerobic load (4.5% body weight). Glucose, hematocrit, CK, ALP, albumin and lactate kinetics during exercise were evaluated by collecting 25µL of blood from the tail of the animals in minutes 0, 10, 20 and 30 of exercise.RESULTS:Two-way ANOVA for repeated measures and post hoc Tukey test showed significant decrease of glycemia after exercise for the DA group, significant increase in CK after exercise for the DA group, significant increase in hematocrit for both groups after exercise and maintenance of ALP after exercise for the DA group.CONCLUSION:The acute aerobic exercise was effective in controlling glucose levels in diabetic rats. However, it should be applied with caution, because it induced high CK values, suggesting possible tissue damage

Effects of Moderate–Intensity Physical Training on Skeletal Muscle Substrate Transporters and Metabolic Parameters of Ovariectomized Rats

A deficit of estrogen is associated with energy substrate imbalance, raising the risk of metabolic diseases. Physical training (PT) is a potent metabolic regulator through oxidation and storage of substrates transported by GLUT4 and FAT CD36 in skeletal muscle. However, little is known about the effects of PT on these carriers in an estrogen-deficit scenario. Thus, the aim of this study was to determine the influence of 12 weeks of PT on metabolic variables and GLUT4 and FAT CD36 expression in the skeletal muscle of animals energetically impaired by ovariectomy (OVX). The trained animals swam 30 min/day, 5 days/week, at 80% of the critical load intensity. Spontaneous physical activity was measured biweekly. After training, FAT CD36 and GLUT4 expressions were quantified by immunofluorescence in the soleus, as well as muscular glycogen and triglyceride of the soleus, gluteus maximus and gastrocnemius. OVX significantly reduced FAT CD36, GLUT4 and spontaneous physical activity (p p < 0.01). PT increased soleus glycogen, and OVX decreased muscular triglyceride of gluteus maximus. Therefore, OVX can cause energy disarray through reduction in GLUT4 and FAT CD36 and their muscle substrates and PT prevented these metabolic consequences, masking ovarian estrogen’s absence

Wide housing space and chronic exercise enhance physical fitness and adipose tissue morphology in rats

2011/16222-7; 2012/20501-1305650/2009-2The current cages commonly used in animal experiments can prevent rats from engaging in most forms of natural locomotion behaviors. These animals tend to exhibit sedentary habits. Here, we show that a combination of wide housing space and training exercise helps to reduce white adipose mass and to increase brown adipose mass. Thus, this combination is a useful strategy for truly enhancing the physical fitness of captive rats commonly used in exercise-related interventional studies and to maximize their welfare.The current cages commonly used in animal experiments can prevent rats from engaging in most forms of natural locomotion behaviors. These animals tend to exhibit sedentary habits. Here, we show that a combination of wide housing space and training exercis405489492FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTIFICO E TECNOLOGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTIFICO E TECNOLOGICO2011/16222-7; 2012/20501-1305650/2009-2FAPESP [2011/16222-7, 2012/20501-1]CNPq [305650/2009-2]2011/16222-7; 2012/20501-1305650/2009-2The current cages commonly used in animal experiments can prevent rats from engaging in most forms of natural locomotion behaviors. These animals tend to exhibit sedentary habits. Here, we show that a combination of wide housing space and training exerci

Núcleos de Ensino da Unesp: artigos 2008

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq