Acute changes in glucose induced by continuous or intermittent exercise in children and adolescents with type 1 diabetes

ABSTRACT Objective: To estimate the rate of change during exercise and during recovery in moderate-continuous exercise (MCE) and high-intensity intermittent exercise (HIIE) in children and adolescents with type 1 diabetes (T1D). Subjects and methods: Participants performed 2 sessions of exercise: thirty minutes of continuous activity on a cycle ergometer (60% of VO2max) and thirty minutes (60% VO2max) interspersed with five bouts of maximum intensity lasting ten seconds every five minutes. Capillary blood glucose was measured before and after each test. The glucose rate of change in exercise (RoCE) was calculated (final blood glucose - onset blood glucose/exercise time), and the glucose rate of change in recovery (RoCR) (blood glucose 30 minutes after exercise - end of exercise blood glucose/recovery time). Results: The study included thirty-one participants (aged 13 ± 1.88 years). A lower blood glucose reduction was observed in the HIIE group, as well as better recovery values before, after, and thirty minutes after the test, respectively (333.14 ± 69.53, 226.19 ± 68.05 and 201.77 ± 66.84 versus 211.36 ± 91.03, 155.98 ± 82,68 and 165.76 ± 72.94). Covariance analyses showed a significant difference in glycemic variation between continuous and intermittent protocols immediately after exercise (−2.90 versus −2.08) and during the recovery period (−0.677 versus −0.389). Conclusions: HIIE led to a lower glucose reduction rate per minute during exercise and better recovery in the first 30 minutes after exercise compared to MCE in children and adolescents with T1D.

Acute exercise inhibits gastric emptying of liquids in rats: influence of the NO-cGMP pathway

We previously found that acute exercise inhibited the gastric emptying of liquid in awake rats by causing an acid-base imbalance. In the present study, we investigated the involvement of the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway, vasoactive intestinal peptide (VIP), and corticotropin-releasing factor (CRF) peptide in this phenomenon. Male rats were divided into exercise or sedentary group and were subjected to a 15-min swim session against a load (2.5 or 5% b.w.). The rate of gastric emptying was evaluated after 5, 10, or 20 min postprandially. Separate groups of rats were treated with vehicle (0.9% NaCl, 0.1 mL/100 g, ip) or one of the following agents: atropine (1.0 mg/kg, ip), the NO non-selective inhibitor Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME; 10.0 mg/kg, ip), or the selective cGMP inhibitor 1H-(1,2,4)oxadiazole[4,3-a]quinoxalin-1-one (ODQ; 5.0 mg/kg, ip), the i-NOS non-specific inhibitor (aminoguanidine; 10.0 mg/kg, ip), the corticotropin-releasing factor receptor antagonist (astressin; 100 µg/kg, ip), or the vasoactive intestinal peptide (VIP) receptor antagonist Lys1, Pro2,5, Arg3,4, Tyr6 (100 µg/kg, ip). Compared to sedentary rats, both the 2.5 and 5% exercise groups exhibited higher (P<0.05) values of blood lactate and fractional gastric dye recovery. Corticosterone and NO levels increased (P<0.05) in the 5% exercised rats. Pretreatment with astressin, VIP antagonist, atropine, L-NAME, and ODQ prevented the increase in gastric retention caused by exercise in rats. Acute exercise increased gastric retention, a phenomenon that appears to be mediated by the NO-cGMP pathway, CRF, and VIP receptors.

High-CHO diet increases post-exercise oxygen consumption after a supramaximal exercise bout

We investigated if carbohydrate (CHO) availability could affect the excess post-exercise oxygen consumption (EPOC) after a single supramaximal exercise bout. Five physically active men cycled at 115% of peak oxygen uptake (V̇O2 peak) until exhaustion with low or high pre-exercise CHO availability. The endogenous CHO stores were manipulated by performing a glycogen-depletion exercise protocol 48 h before the trial, followed by 48 h consuming either a low- (10% CHO) or a high-CHO (80% CHO) diet regime. Compared to the low-CHO diet, the high-CHO diet increased time to exhaustion (3.0±0.6 min vs 4.4±0.6, respectively, P=0.01) and the total O2 consumption during the exercise (6.9±0.9 L and 11.3±2.1, respectively, P=0.01). This was accompanied by a higher EPOC magnitude (4.6±1.8 L vs 6.2±2.8, respectively, P=0.03) and a greater total O2 consumption throughout the session (exercise+recovery: 11.5±2.5 L vs 17.5±4.2, respectively, P=0.01). These results suggest that a single bout of supramaximal exercise performed with high CHO availability increases both exercise and post-exercise energy expenditure.

Cytokine Pattern is Affected by Training Intensity in Women Futsal Players

To find the relation between exercise and cytokines, we examined the effect of the training intensity on the levels of cytokines, including interferon-gamma (IFN-γ), interlukine-4 (IL-4) and interlukine-4/interferon-gamma ratio (IL-4/IFN-γ ratio) in female Futsal players. Twelve well-trained female college Futsal players aged 19~22 participated in this study. The athletes completed 30-min of running at 60~65% maximal heart rate [moderate-intensity exercise], and 30-min of running at 75~80% maximal heart rate [high-intensity exercise]. peripheral blood samples were collected 24 h before and 24 h and 48 h after each of the exercise bouts. finding showed that The 30-min bout of moderate-intensity exercise induced a significant increase in IFN-γ (p=0.01) and significant decreases in IL-4 (p=0.001) and IL-4/IFN-γ ratio (p=0.003). And also, 30-min of running at 75~80% maximal heart rate induced increase in IFN-γ (p=0.07) and decreased in IL-4 (p=0.01) and IL-4/IFN-γ ratio (p=0.06) that these changes not significantly. In summary, exercise intensity can effect on the magnitude of changes in cytokines. It seems that moderate intensity exercise enhances cytokine pattern in female college Futsal players.

Association between anaerobic components of the maximal accumulated oxygen deficit and 30-second Wingate test

The purpose of this study was to analyze the relationship between the anaerobic components of the maximal accumulated oxygen deficit (MAOD) and of the 30-second Wingate anaerobic test (30-WAnT). Nine male physical education students performed: a) a maximal incremental exercise test; b) a supramaximal constant workload test to determine the anaerobic components of the MAOD; and c) a 30-WAnT to measure the peak power (PP) and mean power (MP). The fast component of the excess post-exercise oxygen consumption and blood lactate accumulation were measured after the supramaximal constant workload test in order to determine the contributions made by alactic (ALMET) and lactic (LAMET) metabolism. Significant correlations were found between PP and ALMET (r=0.71; P=0.033) and between MP and LAMET (r=0.72; P=0.030). The study results suggested that the anaerobic components of the MAOD and of the 30-WAnT are similarly applicable in the assessment of ALMET and LAMET during high-intensity exercise.

Molecular and metabolic insights of creatine supplementation on resistance training / Perspectivas moleculares y metabólicas de la suplementación con creatina en el entrenamiento de fuerza / Perspectivas moleculares e metabólicas da suplementação de creatina no treinamento de força

In recent years the research problem in the field of sports supplementation has changed to explain the metabolic mechanisms by which creatine (Cr) administration enhances the performance of certain sports or simply benefits the muscular adaptation. In this review for first time the biochemical mechanisms of Cr ingestion in a cell signaling insight were analyzed, focusing on energetic bioavailability enhancement and optimization of the temporal and spatial buffering of Cr/PCr/CK system. Moreover, intensification in proliferation and differentiation processes of muscle cells (IGF-I/PI3K/Akt-PKB, SPHK1/MAPK/p38/MRFs, mTOR, cellular swelling, mitotic activity of satellite cells, actin polymerization, and myoblast fusion) and inactivation and/or reduction in the expression of ergolitic metabolites (GSK3β, myostatin and AMPK regulation) were examined. In this way, we explained from a metabolic point of view the increase in muscle mass, strength, fatigue resistance, and performance of high intensity sports after Cr monohydrate supplementation.

En los últimos años el problema de investigación en el campo de la suplementación deportiva ha cambiado al punto de explicar los mecanismos metabólicos por los cuales la administración de creatina (Cr) incrementa el rendimiento en ciertos deportes o simplemente beneficia la adaptación muscular. Esta revisión analiza por primera vez los mecanismos bioquímicos de la ingesta de Cr desde la perspectiva de señalización celular, enfocándose en la mayor biodisponibilidad energética de Cr y optimización de la acción buffer espacial/temporal que ofrece el sistema Cr/PCr/CK. Además, se examinan aspectos relacionados con el incremento en los procesos de proliferación y diferenciación de células musculares (IGF-I/PI3K/Akt-PKB, SPHK1/MAPK/p38/MRFs, mTOR, hinchamiento celular, actividad mitótica de células satélite, polimerización de actina y fusión de mioblastos) y la inactivación y/o reducción en la expresión de proteínas con funciones ergolíticas (GSK3β, miostatina y regulación de AMPK). De esta manera, se explican el aumento de la masa muscular, la fuerza, la resistencia a la fatiga y el rendimiento en ejercicios de alta intensidad, producidos por la suplementación con monohidrato de Cr, desde un punto de vista metabólico.

Nos últimos anos, o problema de pesquisa no campo da suplementação de esportes mudou ao ponto de explicar os mecanismos metabólicos pelos quais a administração de creatina (Cr) aumenta o desempenho em alguns esportes ou benefícios de adaptação musculares. Neste artigo, vamos analisar primeiro os mecanismos bioquímicos de ingestão da Cr a partir da perspectiva de sinalização celular, com foco em maior biodisponibilidade de energia de Cr e otimização de tampão temporais/espacial ação oferecida pelo sistema Cr/PCr/CK. Além disso, são considerados aspectos relacionados com o aumento da os processos de proliferação e diferenciação de células musculares (IGF-I/PI3K/Akt-PKB, SPHK1/MAPK/p38/MRFs, mTOR, inchaço celular, atividade mitótica da célula satélite, a polimerização de actina e de fusão de mioblastos) e inativação e/ou a redução na expressão de proteínas com funções ergolíticas (GSK3, miostatina e regulação da AMPK). Desta maneira, é explicado o aumento da massa muscular, força, resistência à fadiga e desempenho em exercícios de alta intensidade, produzidos pela suplementação com Cr monohidratada, a partir de um ponto de vista metabólico.

Ciclismo arriba del umbral de lactato es más efectivo que abajo para la liberación de óxido nítrico y reducción de la presión arterial después del ejercicio en individuos con diabetes tipo 2 / Ciclismo acima do limiar de lactato é mais efetivo que abaixo para liberação de óxido nítrico e redução da pressão arterial pós-exercício em indivíduos com diabetes tipo 2 / Cycling above rather than below lactate threshold is more effective for nitric oxide release and post-exercise blood pressure reduction in individuals with type-2 diabetes

The purposes of this study were to analyze and compare the effects of exercise performed in different intensities, above and below lactate threshold (LT) on post-exercise blood pressure (BP) and nitric oxide (NO) responses in individuals with type 2 diabetes (T2D). For this, 11 T2D underwent the following sessions: 1) control session; 2) 20-min of moderate cycling (80% LT); and 3) 20-min of high intensity cycling (120%LT) on a cycle ergometer. Plasma NO and BP measurements were carried out at rest and at 15 and 45 min of post-sessions. When compared to rest, only the exercise session performed at 120%LT elicited an increase of NO (from 7.2 to 9.5 µM, p<0.05), as well as a decrease in systolic BP (from 126.6±7.9 to 118.7±3.9 mmHg, p<0.05) during the post-exercise period. In conclusion, the results suggest that NO release and post-exercise BP decrease are intensity-dependent for individuals with T2D.

Os objetivos do presente estudo foram analisar e comparar os efeitos do exercício realizado em diferentes intensidades, acima e abaixo do limiar de lactato (LL), sobre a resposta da pressão arterial (PA) e óxido nítrico (NO) em indivíduos com diabetes tipo 2 (DM2). Para tanto, 11 DM2 foram submetidos às seguintes sessões: 1) sessão controle; 2) 20 min de exercício em cicloergômetro em intensidade moderada (80%LL); e 3) 20 min de exercício em cicloergômetro em alta intensidade (120%LL). O NO plasmático e as medidas de PA foram realizadas no repouso, bem como aos 15 e 45 min do período de recuperação de todas as sessões. Quando comparado ao período de repouso, somente a sessão de exercício realizado a 120%LL promoveu aumento do NO (de 7,2 para 9,5 µM, p<0,05) e, por conseguinte, uma diminuição na pressão arterial sistólica (de 126,6±7,9 para 118,7±3,9 mmHg, p<0,05) durante o período de recuperação pós-exercício. Em conclusão, os resultados sugerem que a liberação de NO e a diminuição da PA parecem ser intensidade-dependente para indivíduos com DM2.

Los objetivos del presente estudio fueron examinar y comparar los efectos del ejercicio realizado en diferentes intensidades, arriba y abajo del umbral de lactato (UL), sobre la respuesta de la presión arterial (PA) y el óxido nítrico (NO) en individuos con diabetes tipo 2 (DM2). Por lo tanto, 11 DM2 se sometieron las siguientes sesiones: 1) sesión control; 2) 20 min de ejercicio en cicloergómetro a una intensidad moderada (80%UL); y 3) 20 min de ejercicio en cicloergómetro a una intensidad alta (120%UL). El NO plasmático y las mediciones de la PA fueron realizados en reposo y en 15 y 45 min del período de recuperación para todas las sesiones. En comparación con el período de reposo, sólo la sesión de ejercicio realizado a 120%UL promovió aumento de NO (7,2 para 9,5 µM, p<0,05) y, por lo tanto, una disminución de la presión arterial sistólica (de 126,6±7,9 para 118,7±3,9 mmHg, p<0,05) durante el período de recuperación después del ejercicio. En conclusión, los resultados sugieren que la liberación de NO y la disminución de PA parece ser intensidad-dependiente para individuos con DM2.

Análise da cinética de remoção de lactato em atletas de canoagem slalom / Analysis of the kinetics of lactate removal in slalom kayak athletes / Análisis de la cinética de la eliminación de lactato de atletas de piragüismo slalom

O objetivo do presente estudo foi verificar a cinética de produção e remoção de lactato em atletas de canoagem slalom da categoria K1, durante competição oficial. Participaram do estudo oito atletas do sexo masculino (22,6 ± 4,3 anos). Foram realizadas coletas de 25µL de sangue capilar para análise do lactato. A cinética de remoção do lactato foi realizada antes do aquecimento (Pré), logo após a saída dos competidores do rio (Pós 0'), 5 (Pós 5') e 20 (Pós 20') minutos. Os resultados demonstraram um aumento significativo nas concentrações de lactato (9,8 mmol/l, 9,4 mmol/l e 6,6 mmol/l) nos tempos 0', 5' e 20' minutos pós respectivamente, com valores de P<0,01. Os achados indicam que após 20 minutos, os valores de lactato se reduziram de forma importante (P<0,05) em relação aos valores pré exercício (2,0 mmol/l), sugerindo que os atletas indicariam boas condições metabólicas para a segunda descida da prova.

The aim of this study was to verify the kinetics of lactate production and removal in slalom kayak athletes, K1 category, during official competition. Eight male athletes (22,6 ± 4,3 years) participated of the study. For the analysis of lactate, 25µL of capillary blood were collected. The kinetics of lactate removal was performed before the warm-up (Pre), just after the competitors exit from the river (Post 0'), 5 (Post 5'), and 20 (Post 20') minutes. The results demonstrated a significant increase in lactate concentrations (9.8 mmol/l, 9.4 mmol/l and 6.6 mmol/l) at 0', 5' and 20' post respectively, with values of P<0.01. The findings indicate that after 20 minutes the values of lactate reduced significantly (P<0.05) compared to Pre exercise, suggesting that the athletes would indicate good metabolic conditions for the second turn of the race.

El objetivo de este estudio fue examinar la cinética de la producción y la remoción de lactato en atletas de slalom piragüismo, categoría K1, durante la competición oficial. En el estudio participaron ocho hombres (22,6 ± 4,3 años), con 25µL de muestras de sangre para el análisis de lactato. La cinética de eliminación de lactato se realizó antes del calentamiento (Pre), poco después de la salida de los competidores del rio (Post 0'), 5 (Post 5') y 20 (Post 20') minutos. Los resultados mostraron un aumento significativo en la concentración lactato (9.8 mmol/l, 9.4 mmol/l e 6.6mmol/l) en los tiempos 0', 5' e 20' minutos respectivamente, con valores de P<0,01. Resultados indican que después de 20 minutos los valores de lactato se redujeron significativamente (P<0,05) en comparación con el ejercicio anterior, lo que sugiere buenas condiciones metabólicas para el segundo descenso de la prueba.

THE SYNERGIC EFFECTS OF COENZYMEQ10 AND CREATINE THROUGH ORAL INTAKE ON REPETITIVE SHORT DURATION HIGH-INTENSITY EXERCISE / 体力科学

A double-blind placebo-controlled trial was undertaken to evaluate the synergic effects of coenzymeQ10 (CoQ10) and creatine (Cr) through oral supplementation on the intermittent short duration high-intensity exercise on a cycle ergometer. Twenty-eight male athletes were divided into four groups of CoQ10 and Cr (CoQ10+Cr), CoQ10 (CoQ10+Pl), Cr (Pl+Cr) and placebo group (Pl+Pl). Each participant was instructed to have 100 mg of CoQ10 and/or 5 g of Cr per day for 2 weeks. Repetitive 5 bouts of 10-sec high-intensity cycle exercise tests were performed before and after supplementations. After supplementations, subjects in (CoQ10+Cr) revealed most improved performance in mean power outputs at the 2^nd (p<0.05), the 3^rd (p<0.05), the 4^th (p<0.05) and the 5^th set (p=0.06), comparing with the participants in the other 3 groups. These findings suggest that enhanced mean power output on repetitive short duration high-intensity exercise can be acquired after supplementing CoQ10 combined with Cr.