THE EFFECT OF BCAA ON ISOMETRIC FORCE FOLLOWING ENDURANCE EXERCISE IN A HOT ENVIRONMENT
THE EFFECT OF BCAA ON ISOMETRIC FORCE FOLLOWING ENDURANCE EXERCISE IN A HOT ENVIRONMENT
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DOI：
10.1590/1517-869220192501178036
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发表时间：
2019-02-01
影响因子：
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通讯作者：
Soares, Danusa Dias
中科院分区：
文献类型：
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作者：
Moraes, Michele Macedo;Paulinelli-Júnior, Reinaldo Teles;Soares, Danusa Dias
简介：耐力运动引起的疲劳是外周和中枢变化的结果，并可能影响随后在力量任务中的表现，5-羟色胺浓度的增加是与耐力运动引起的疲劳相关的核心因素之一，特别是在炎热的环境中。一种用于减少维生素E能激活的营养策略是补充支链氨基酸（BCAA）。目的：研究补充支链氨基酸是否能减弱高温环境下耐力运动引起的等长收缩力下降。研究方法：9名志愿者（年龄25.4 ± 1.2岁）在自行车测力计上以40%的最大有氧功率进行耐力运动之前和之后进行了2分钟的上肢肌肉最大自主等长收缩（MVCISO）。志愿者接受了三项实验性试验：（1）在温和环境（23摄氏度和60%相对湿度）中进行耐力运动;在炎热环境（35摄氏度和60%相对湿度）中进行运动，并摄入：2）安慰剂溶液或（3）含有BCAA的溶液30 mg.kg（-1）。在MVC 150试验中，测量右肘屈肌等长肌力、核心体温（Tcore）和心率（HR）。结果：热环境下耐力运动后，等长肌力下降，BCAA给药并不能减弱这种下降。与运动前相比，在高温下进行耐力运动后观察到更大的Tcore和HR值，并且补充剂不会干扰这些生理反应。结论：补充支链氨基酸并不能减轻先前在炎热环境中进行耐力运动所引起的等长收缩力的降低。
Introduction: Fatigue due to endurance exercise results from both peripheral and central changes, and may influence subsequent performance during a strength task.The increase in serotonin concentration is one of the central factors associated with endurance exercise-induced fatigue, particularly in hot environments. A nutritional strategy employed to reduce serotonergic activation is supplementation with branched-chain amino acids (BCAA). Objective: To investigate whether BCAA supplementation attenuates the reduction in isometric force caused by prior endurance exercise in a hot environment. Methods: Nine volunteers (aged 25.4 +/- 1.2 years) performed a 2-min maximal voluntary isometric contraction (MVCISO) of upper limb muscles before and after an endurance exercise on a cycle ergometer at 40% of the maximal aerobic power. The volunteers underwent three experimental trials: (1) endurance exercise in a temperate environment (23 degrees C and 60% RH); exercise in a hot environment (35 degrees C and 60% RH) with the ingestion of: 2) a placebo solution or (3) a solution containing BCAA 30 mg.kg(-1). During the MVCIso test, the isometric force of flexor muscles of the right elbow, core body temperature (Tcore) and heart rate (HR) were measured. Results: Isometric force decreased following endurance exercise in the hot environment, and BCAA administration did not attenuate this reduction. Greater Tcore and HR values were observed following endurance exercise in the heat, compared to pre-exercise values, and supplementation did not interfere with these physiological responses. Conclusion:The reduction in isometric force, caused by previous endurance exercise in a hot environment, was not diminished by supplementation with BCAA.