Background Few studies have demonstrated the suppressive effects of amino acids (AAs) on the level of cortisol during exercise in humans. We hypothesized that an AA mixture containing arginine, which promotes lipid metabolism, valine, which effectively decreases the level of glucocorticoid, and serine, a substrate in the production of phosphatidylserine that is reported to blunt increases in cortisol, would suppress the exercise-induced cortisol response by combining the positive effects of the AAs synergistically. Methods A randomized, double-blinded, placebo-controlled crossover trial was conducted. Twenty healthy recreationally active males ingested either an AA mixture containing 1.8 g of arginine, 1.1 g of valine, and 0.1 g of serine or a placebo. Thirty minutes after ingestion, subjects performed an exercise trial on a cycle ergometer for 80 min at 50% maximal oxygen consumption. Plasma cortisol and other blood parameters immediately before and after the exercise were evaluated. Results Plasma cortisol concentrations after exercise were significantly higher than those before exercise in the placebo condition (9.51 ± 0.85 vs 14.39 ± 2.15, p < 0.05), while there was no significant difference in the AA condition (9.71 ± 0.93 vs 9.99 ± 1.23, p = 0.846). In addition, the increase in plasma cortisol before and after exercise was significantly lower in the AA condition than in the placebo condition (0.28 [− 2.75, 3.31] vs 4.87 [0.89, 8.86], p < 0.05). For the level of adrenocorticotropin, there was a significant difference between before and after exercise only in the placebo condition (24.21 ± 2.91 vs 53.17 ± 6.97, p < 0.01) but not in the AA condition (27.33 ± 3.60 vs 46.92 ± 10.41, p = 0.057). Blood glucose, plasma lactate, plasma ammonia, serum creatine phosphokinase, serum total ketone body, and serum free fatty acid were also significantly changed by the exercise load in both conditions, but no significant differences were observed between the two conditions. Conclusions The present study demonstrated that the AA mixture suppressed the cortisol response during exercise without affecting exercise-related biological parameters such as glucose or lipid metabolism. Trial registration UMIN Clinical Trials Registry, UMIN000023587 . Registered 19 August 2016.

中文翻译：

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急性补充氨基酸混合物可抑制休闲活动的健康志愿者的运动诱发的皮质醇反应：一项随机、双盲、安慰剂对照的交叉研究

背景 很少有研究证明氨基酸 (AA) 对人体运动过程中的皮质醇水平有抑制作用。我们假设，含有促进脂质代谢的精氨酸、有效降低糖皮质激素水平的缬氨酸和丝氨酸（据报道可抑制皮质醇增加的磷脂酰丝氨酸产生的底物）的 AA 混合物会抑制运动诱发的皮质醇通过协同结合 AA 的积极作用来做出反应。方法进行了一项随机、双盲、安慰剂对照的交叉试验。20 名健康的娱乐性活跃男性摄入了含有 1.8 克精氨酸、1.1 克缬氨酸和 0.1 克丝氨酸的 AA 混合物或安慰剂。摄入后三十分钟，受试者在自行车测力计上以 50% 的最大耗氧量进行了 80 分钟的运动试验。立即评估运动前后的血浆皮质醇和其他血液参数。结果安慰剂组运动后血浆皮质醇浓度显着高于运动前（9.51±0.85 vs 14.39±2.15，p < 0.05），而AA组无显着差异（9.71±0.93 vs 9.99±1.23， p = 0.846）。此外，AA条件下运动前后血浆皮质醇的增加显着低于安慰剂条件（0.28 [- 2.75, 3.31] vs 4.87 [0.89, 8.86], p < 0.05）。对于促肾上腺皮质激素水平，仅在安慰剂条件下运动前后存在显着差异（24.21 ± 2.91 vs 53.17 ± 6.97，p < 0.01）但不是在 AA 条件下（27.33 ± 3.60 vs 46.92 ± 10.41，p = 0.057）。血糖、血浆乳酸、血浆氨、血清肌酸磷酸激酶、血清总酮体和血清游离脂肪酸在两种情况下也因运动负荷而发生显着变化，但两种情况之间没有观察到显着差异。结论 本研究表明，AA 混合物可抑制运动过程中的皮质醇反应，而不会影响与运动相关的生物参数，如葡萄糖或脂质代谢。试验注册 UMIN 临床试验注册，UMIN000023587。2016 年 8 月 19 日注册。和血清游离脂肪酸在两种情况下也因运动负荷而发生显着变化，但两种情况之间没有观察到显着差异。结论 本研究表明，AA 混合物可抑制运动过程中的皮质醇反应，而不会影响与运动相关的生物参数，如葡萄糖或脂质代谢。试验注册 UMIN 临床试验注册，UMIN000023587。2016 年 8 月 19 日注册。和血清游离脂肪酸在两种情况下也因运动负荷而发生显着变化，但两种情况之间没有观察到显着差异。结论 本研究表明，AA 混合物可抑制运动过程中的皮质醇反应，而不会影响与运动相关的生物参数，如葡萄糖或脂质代谢。试验注册 UMIN 临床试验注册，UMIN000023587。2016 年 8 月 19 日注册。试验注册 UMIN 临床试验注册，UMIN000023587。2016 年 8 月 19 日注册。试验注册 UMIN 临床试验注册，UMIN000023587。2016 年 8 月 19 日注册。