Influência da ordem dos exercícios sobre a resposta do hormônio do crescimento e cortisol / Influence of exercise order in GH and cortisol hormonal response

O objetivo deste estudo foi investigar a resposta hormonal aguda ao treinamento de força em diferentes ordens de exercícios. Dez homens treinados (22,4 ± 2,7 anos; 80,3 ± 5,7 kg; 180 ± 8 cm; 21,5 ± 0,3 kg.m-2) participaram do estudo e completaram dois protocolos experimentais com diferentes ordenações de exercícios. As sequências foram compostas de três séries para cada exercício usando 70% de 1RM, com dois minutos de intervalo de descanso entre séries e exercícios com intervalo de sete dias entre elas. A ordem dos exercícios para SEQA foram: supino reto (SR), puxada no pulley pela frente (PF), desenvolvimento (DES), rosca direta (RD) e tríceps no pulley (TP). A ordem dos exercícios para SEQB foram TP, RD, DES, PF e SR. As variáveis sanguíneas analisados foram hormônio de crescimento (GH) e cortisol pré e imediamente pós-esforço a execução da sessão de treinamento. Os resultados demonstram que a SEQA promoveu maior e significativo aumento na concentração do GH imediatamente após a sessão, quando comparado a SEQB. A concentração de cortisol apresentou um aumento significativo quando comparado os momentos pré e pós para ambas as sequências. No entanto, não houve diferença estatisticamente significativa quando feita a comparação entre as sequências. Portanto, parece que a ordem dos exercícios pode influenciar as respostas do GH sendo que exercícios para grandes grupos musculares promovem um aumento significativo deste hormônio do que exercícios para pequenos grupos musculares no início da sessão.

The aim of this study was to investigate the acute hormonal response to resistance training sessions with different exercises order in men. Ten recreationally trained men (22.4 ± 2.7 years; 80.3 ± 5.7 kg; 180 ± 8 cm; 21.5 ± 0.3 kg.m-2) participated in the study. All subjects completed two experimental protocols with different exercises order. The exercise sequences were composed by three sets using 70%of 1RM for each exercise with 2 minutes rest between sets and exercises and separated by seven days between them. Exercise order for SEQA was bench press (BP), lat-pull down (LPD), seated shoulder press(SP), biceps curl (BC) and tríceps extension (TE). The exercises order for SEQB order were TE, BC, SP,LPD and BP. The blood variables analyzed were: growth hormone (GH), cortisol before (Pre) and immediately after (Post) each exercise session. The results shown that SEQA promoted higher and significantly increases in GH concentration immediately post session, as compared with SEQB. The cortisol concentration presented a significantly increase when compared pre and post moments for both sequences. However, there were not statistically differences when compared SEQA and SEQB post session. In conclusion, seems that exercises order can influences the GH responses, being exercises for large muscle group promoted a significantly increase in this hormone than exercises for small muscle group at the beginning of training session.

Fatores relacionados com as respostas da testosterona e do cortisol ao treinamento de força / Factors concerned with the testosterone and cortisol response to strength training

Esse artigo visa revisar os resultados encontrados na literatura a respeito dos diversos fatores relacionados com a resposta hormonal aguda e crônica ao treinamento de força. Foi observado que existe uma estreita relação entre a treinabilidade de indivíduos submetidos ao treinamento de força e os níveis circulantes de testosterona nesses sujeitos. Além disso, outros parâmetros hormonais, tais como as razões entre a testosterona e sua proteína carreadora e entre a testosterona com o cortisol, também foram relacionados com a capacidade de aumento de força. Diversos fatores ligados à sessão de treino, além das características da população investigada, influenciam a resposta hormonal aguda e crônica ao treinamento. Entre esses fatores, o volume e a intensidade são as principais variáveis ligadas à magnitude dessa resposta. A determinação de quais fatores possam estar estreitamente relacionados com a resposta hormonal ao treinamento de força pode ser importante para o estabelecimento de uma sessão de treino e uma periodização que otimizem o ambiente anabólico determinado pelas concentrações de testosterona e cortisol, e, dessa forma, maximizar os ajustes neuromusculares decorrentes desse tipo de treinamento.

This study aims to review the results found in the literature concerning a variety of factors related to the acute and chronic hormonal response to strength training. It has been observed that there is a close relationship between the trainability of individuals submitted to strength training and the circulating testosterone levels in these subjects. Moreover, other hormonal parameters, such as the ratios between testosterone and its binding protein and between testosterone and cortisol, were also related to the ability to increase strength. Besides the characteristics of the population investigated, several factors associated with the training session affect the acute and chronic hormonal response to training. Among them, volume and intensity are the main variables associated with the magnitude of this response. Determining which factors might be closely related to the hormonal response to strength training may be important to establish a training session and a periodization that optimize the anabolic environment determined by the testosterone and cortisol concentrations, and thus enhance the neuromuscular adaptations resulting from this type of training.

Hemodynamic Responses of Systemic and Pulmonary Vessels to Head-down Tilt (-6 degrees) and Effect of Anticholinergic Agent

Head-down tilt (HDT) has been commonly used as the simulation of a microgravity to evaluate the hemodynamic and the hormonal responses to the central blood shift observed during the spaceflight. But there were some differences in the systemic responses according to species or angle of tilt, and there are few reports in the hemodynamic response and the regulation on polmonary vascular bed during the early stage of HDT. This study was attempted to clarify the regulatory mechanism on the systemic and pulmonary vascular responses through the low pressure receptor, and the hormonal changes to the -6 degrees HDT, and to investigate the effect of anticholinergic agent, glycopyrrolate, on the hemodynamic and the hormonal responses. In 28 anesthetized dogs(8~14 kg), 15 dogs(TILT group) were tilted from the supine position to the -6 degrees head-down position(HDP ) for 30 minutes, then back to the supine recovery position for the next 30 minutes, and the same tilt procedure was taken at 20 minutes after the intra venous administration of 0.2g glycopyrrolate. The rest 13 dogs were kept in the supine position without tilt as the control group(CONT group ) for the same time course of the TILT group. Cardiac output(Q), heart rate(HR), stroke volume(SV), index of contractility(IC) and thoracic fluid volume(TFV) were deterkuned by the impedance cardiograph. Systemic arterial pressure (SAP) and pulmonary arterial pressure(PAP) were measured at the brachial and pulmonary arteries respectively, and central venous pressure(CVP) also at the right atrium. And systemic and pulmonary vascular resistances (SVR and PVR) were calculated. The concentration of plusma ANP and ADH in the arterial blood were measured by the radioimmunoassay in 8 dogs in each group at 5 minutes before, and 25 and 55 minutes after begining of the tilt. During the HDP, Q, SV and TFV increased to 9%,10.6% and 12.6ml respectively in the TILT group, where as they decreased by 10%, 13.8% and 7.5ml respectively in the CONT group. SAP, PAP and HR did not change significantly in the TILT group, but SAP and HR increased in the CONT group. At the same time, SVR and PVR reduced significantly by 4.5% and 8.9% respectively at 15 minutes of HDP in the TILT group, where as they elevated gradually to 21.8% and 13.4% respectively at the first 30 runutes In the CONT group. There were no significant differences in the changes of HR, PAP and CVP between the TILT and the CONT group. And the plasma ANP and ADH did not change significantly in the both groups. After the administration of glycopyrrolate, SAP and SVR Increased to 3.7mmHg and 5.1% respectively, and PAP, PVR, Q, HR, and SV did not change significantly during the HDP in the TILT group. There was no significant difference in the change of each hemodynamic parameter between the TILT and the CONT group, except in TFV, which showed the same change as that before the administration of glycopyrrolate in the both groups. The plsma ANP showed nonslgnificant increased trend at the HDP in the TILT group but did not change In the CONT group, and the plasma ADH showed nonsignificant decreased trend in the both groups. In summary, the cardiopulmonary baroreceptors induced the vasodilations of both systemic and pulmonary vessels by the expansion of thoracic fluid volume at the head-down tilt, and the anticholinergic agent(glycopyrrolate) tended to attenuate the hemodynamic responses to the tilt. The concentration of the plasma ANP and ADH did not show significant changes in this study. It is suggested that the regulatory mechanism inducing the systeruc and pulmonary vats odilation during the early phase of the head-down tilt is mediated by the cholinergic vasodilator fiber in the dog.