| 摘要: | 支鏈胺基酸 (branched-chain amino acids, BCAA) 、精胺酸 (arginine, Arg) 和瓜胺酸 (citrulline, Cit) 具多種生理功能，補充BCAA可能可以降低游離色胺酸 (free tryptophan) 進入大腦，進而降低血清素 (serotonin) 合成，延緩中樞疲勞；補充Arg與Cit可能促進尿素循環，加速血氨轉換成尿素。綜合補充BCAA、Arg與Cit，可能降低運動誘發之中樞疲勞。目的：探討合併補充BCAA、Arg與Cit對跆拳道模擬比賽後，中樞疲勞與反應式專項技術測試之影響。方法：以12位男性大學優秀跆拳道選手為對象，採交叉平衡次序之實驗設計。以間歇性運動型態模擬跆拳道比賽中之負荷，每位受測者需進行三次的腳踏車間歇性衝刺運動，每次運動中含3回合，每回合包含4個間歇型運動 (5秒全力衝刺及25秒休息之交替) ，衝刺的阻力為0.1 kp/kg，每回合2分鐘，回合間休息1分鐘。在第三次運動開始前60分鐘，補充0.17 g/kg BCAA、0.05 g/kg Arg與0.05 g/kg Cit (AA 測試) 或安慰劑 (PL測試；麥芽糊精與維生素E)。跆拳道反應式專項技術測試於早餐食用後1小時、第一、第二與第三次運動後進行測驗，包括測定前動作反應時間 (premotor reaction time, PRT)、動作反應時間 (motor reaction time, MRT) 、反應時間 (reaction time, RT) 、動作時間 (movement time, MT) 、總反應時間 (total response time, TRT) 、與雙任務測驗 (dual task) 情況下的第二任務時間。血液採集於早餐前、第一次運動後、第二次運動後以及第三次運動前與運動後，共五個採血點，分析血漿中支鏈胺基酸、色胺酸、氮氧化物、氨、尿素、葡萄糖、甘油、非酯化脂肪酸和乳酸濃度，並於早餐前、第一次運動前與運動後、第二次運動前與運動後以及第三次運動前與運動後，詢問運動自覺強度 (ratings of perceived exertion, RPE)。結果：在評估中樞疲勞的指標中，AA測試在第三次運動後的PRT (A動作0.142±0.016 s；B動作0.141±0.018 s；C動作0.139±0.015 s；D動作0.139±0.012 s)、第二任務反應時間 (0.259±0.030 s) 均顯著快於PL測試 (PRT：A動作0.166±0.016 s；B動作0.163±0.023 s；C動作0.162±0.009 s；D動作0.168±0.024 s；第二任務反應時間：0.293±0.049 s) ，血漿Trp/BCAA比值(35.0±4.3) 亦顯著低於PL測試 (70.0±9.6)，但RPE值在兩測試間無顯著差異；血液生化值部分，AA測試在第三次運動後的氮氧化物 (13.2±5.7 μM) 顯著高於PL測試 (8.2±4.0 μM)，而氨、尿素、葡萄糖、甘油、非酯化脂肪酸和乳酸在兩測試間無顯著差異；在運動表現中，兩測試間的平均功率總合與最大功率總和於三次運動中皆無顯著差異。結論：跆拳道選手在運動前合併補充BCAA、Arg與Cit，可降低大腦中樞處理反應時間 (PRT) 、提升運動後的注意力，因此可能具有延緩中樞疲勞的作用；補充Arg與Cit可增加氮氧化物濃度，但對加速代謝產物例如氨、尿素與乳酸，以及萄萄糖、甘油、非酯化脂肪酸則無顯著影響。
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. |
