Colombani P C, Bitzi R, Frey-Rindova P, Frey W, Arnold M, Langhans W, Wenk C
Swiss Federal Institute of Technology, Zurich.
Eur J Nutr. 1999 Dec;38(6):263-70. doi: 10.1007/s003940050076.
Athletes consume arginine and/or aspartate as potential nutritional ergogenics. Their metabolic effects are controversial and there is some evidence that ingestion of large doses of single amino acids can adversely affect the nitrogen balance or induce an amino acid imbalance. Nevertheless, the general metabolic influence of an arginine aspartate supplementation during a prolonged exercise bout has not yet been investigated.
The aim of this study was, therefore, to investigate the general metabolic impact of a chronic supplementation with arginine aspartate in endurance-trained athletes at rest and during a marathon run.
Fourteen endurance-trained runners participated in this field study which was carried out according to a double-blind crossover design. 15 g of arginine aspartate or a carbohydrate-based placebo were supplemented daily for 14 days before a marathon run. Blood samples for analysis of metabolites and hormones were collected shortly before the run, after 31 km, at the end of the run, and after a recovery period of two hours. Additionally, the respiratory exchange ratio was determined during the run.
The plasma level of carbohydrate (glucose, lactate, pyruvate) and fat metabolites (fatty acids, glycerol, beta-hydroxybutyrate), cortisol, insulin, ammonia, lactate dehydrogenase, and creatine kinase as well as the respiratory exchange ratio were unaffected by the supplementation. In contrast, the plasma level of somatotropic hormone, glucagon, urea, and arginine were significantly increased, and the level of most of the remaining plasma amino acids as well as their sum was significantly reduced.
There was no obvious metabolic benefit derived from the chronic supplementation with arginine aspartate. And since furthermore the consequences of a reduction of the total plasma amino acid level are not known, the practice of using single amino acid supplements as potential ergogenics should be critically reevaluated.
运动员将精氨酸和/或天冬氨酸作为潜在的营养增强剂来食用。它们的代谢作用存在争议，并且有一些证据表明，摄入大剂量的单一氨基酸会对氮平衡产生不利影响或导致氨基酸失衡。然而，在长时间运动期间补充精氨酸天冬氨酸对整体代谢的影响尚未得到研究。
因此，本研究的目的是调查在耐力训练的运动员休息时以及马拉松跑步期间长期补充精氨酸天冬氨酸对整体代谢的影响。
14名耐力训练的跑步者参与了这项现场研究，该研究按照双盲交叉设计进行。在马拉松跑步前14天，每天补充15克精氨酸天冬氨酸或基于碳水化合物的安慰剂。在跑步前不久、31公里后、跑步结束时以及两小时的恢复期后采集血液样本，用于分析代谢物和激素。此外，在跑步期间测定呼吸交换率。
补充剂对碳水化合物（葡萄糖、乳酸、丙酮酸）和脂肪代谢物（脂肪酸、甘油、β-羟基丁酸）、皮质醇、胰岛素、氨、乳酸脱氢酶和肌酸激酶的血浆水平以及呼吸交换率没有影响。相比之下，生长激素、胰高血糖素、尿素和精氨酸的血浆水平显著升高，其余大多数血浆氨基酸的水平及其总和显著降低。
长期补充精氨酸天冬氨酸没有明显的代谢益处。而且由于血浆总氨基酸水平降低的后果尚不清楚，应严格重新评估将单一氨基酸补充剂作为潜在增强剂的做法。
