The role of metaboreceptor on exercise in hyperthermic environment with college basketball players.

Hyun-Gook Kim,Kyung-Ae Kim,Jong-Kyung Kim,Myoung-Jae Chang,Hyun-Min Choi,Hosung Nho,Sungchul Lee

doi:10.1186/s40064-016-1989-8

Abstract

The objective of this study is to review physiological differences of college basketball players cardiovascular responses and group IV metaboreceptor interactions appearing post muscular ischemia exercise (PEMI) caused by a static handgrip exercise (SHE). The subjects were placed in a temperature and moisture stabilized indoor environment for 2 h in order to measure blood pressure. For the SHE, maximal voluntary contraction of arms with a relative strength of 50 % of the maximum muscular strength was put into isometric training for 2 min. After completing the exercises, cuffs worn on the arms of the subjects were pressurized up to 200 mmHg by applying PEMI to block the artery and vein. In this way, the cardiovascular responses created by SHE and PEMI were measured. Blood samples of subjects were collected from the vein of each upper arm before SHE and after PEMI to measure the metabolite hormone and catecholamine in the blood. Results from the measurements showed a significant decrease of blood pressure under high temperature environments compared to normal temperature environments. With respect to PEMI, increases in blood pressure under the high temperature environment were significantly lower compared to the normal temperature environment. In conclusion, this study revealed that college basketball players with good physical strength had higher sensitivities of arterial baroreceptor. However, blood pressure was not increased accordingly because the increase of cutaneous vasoconstriction due to stimuli of the metaboreceptor under a high temperature environment could not be compensated by arterial baroreflex due to the increase of total vascular conductance.

Highlights

It is known that the human body uses 20 % of produced energy for the function of the tissue and contraction
ΔTVC were significantly increased in the normothermic to the hyperthermic environment (p < 0.05) (Fig. 1)
Our study revealed a statistically significant increase in cardiac output (CO) and Total vascular conductance (TVC) in Mean arterial pressure (MAP) in the hyperthermic environment compared to the normothermic environment

Summary

Introduction

It is known that the human body uses 20 % of produced energy for the function of the tissue and contraction. The heat generated needs to radiate to the skin exposed to the surrounding environment through blood flow. Heat between the human body and the surrounding environment is constantly transferred to maintain the core temperature. Exercise demands increased blood volume of the skin to radiate heat (Rowell and Blackmon 1986; Rowell et al 1986), resulting in decreased blood volume returning into the heart. Exercise in a hyperthermic environment increases the cardiac output (CO) to increase blood volume to skeletal muscles, resulting in decreased blood volume into the liver, kidney and skin due to the redistribution of the amount of CO (Crandall 2000). During exercise in a hyperthermia environment, simultaneous physiological responses to increase the blood volume into skin and skeletal muscles.

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Results

Discussion

Conclusion