Effects of Branched-Chain Amino Acids, Arginine, and Citrulline Supplementation on Reactive Sport-Specific Skills and Central Fatigue in Taekwondo Athletes

• Main Authors: Chen, I-Fan, 陳一凡
• Other Authors: Wu, Huey-June
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/04004967648232538241

博士 === 中國文化大學 === 體育學系運動教練碩博士班 === 103 === Branched-chain amino acids (BCAA), arginine (Arg) and citrulline (Cit) are involved in multiple physiological functions. The supplementation of BCAA could reduce cerebral uptake of free tryptophan, leading to the decrease in serotonin synthesis. The lower cerebral serotonin levels may prevent central fatigue. Arg and Cit may alleviate hyperammonemia by increasing urea cycle. The combination of these supplements could reduce central fatigue induced by exercise and improve the performance. Purpose: The purpose of this study was to investigate the effect of supplementation of BCAA, Arg and Cit on central fatigue and the specific test for Taekwondo reactive skills after three intermittent high-intensity exercises. Methods: Twelve elite collegiate male Taekwondo athletes were recruited and randomly assigned in counterbalanced order. Subjects completed the interval exercise imitating the real volume of Taekwondo competition. Each period of exercise contained three 2-min rounds on a 0.1 kp/kg cycloergometer. Each round contained 4 repeats of 5-s sprint and 25-s rest. Each round was separated by a 2-min rest. The supplement contained 0.17 g/kg BCAA, 0.05 g/kg arginine, and 0.05 g/kg citrulline (AA trial) or placebo (maltodextrin and VitE, PL trial) and given 60 min before the third period of exercise. The premotor reaction time (PRT), motor reaction time (MRT), reaction time (RT), movement time (MT), total response time (TRT) and the time of second task in a dual-task scenario were measured in the Taekwondo skill test. The test was conducted 1 hour after the breakfast, and after each round. Plasma concentrations of BCAA, tryptophan, nitrogen oxide (NOx), ammonia, urea, glucose, glycerol, and nonesterified fatty acid (NEFA) were determined. Ratings of perceived exertion (RPE) was also recorded using the Borg scale. Results: The AA trial showed significantly faster PRT (AA trial:A movement 0.142±0.016 s, B movement 0.141±0.018 s, C movement 0.139±0.015 s, D movement 0.139±0.012 s; PL trial: movement 0.166±0.016 s, B movement 0.163±. 0.023 s, C movement 0.162±0.009 s, D movement 0.168±0.024 s). The time of the second trial in dual task (AA trial 0.259±0.030 s; PL trial 0.293±0.049 s) at the end of the third period. The ratio of plasma Trp/BCAA in the AA trial (35.0±4.3) was significantly lower than that in the PL trial (70.0±9.6). The value of RPE was similar between the two trials. The AA trial (13.2±5.7 μM) elicited significantly higher NOx concentrationthan the PL trail (8.2±4.0 μM) in the third period. Nevertheless, the two trials did not appear significant differences in the concentrations of ammonia, urea, glucose, glycerol, NEFA, and blood lactate. The performances of average power value and maximum power value were also similar in each period of intermittent exercise between the two trials. Conclusion: The combination of BCAA, Arg and Cit supplementation could result in better PRT in Taekwondo skill tests after 3 periods of intermittent exercise, possibly throught the attenuation of central fatigue. Combination of Arg and Cit could stimulate the blood vessel dilatation to augment flow of blood via higher NOx concentration. It appeared that the supplement had no significant effect on metabolite removal.