Improved training tolerance by supplementation with α-Keto acids in untrained young adults: a randomized, double blind, placebo-controlled trial.
Improved training tolerance by supplementation with α-Keto acids in untrained young adults: a randomized, double blind, placebo-controlled trial.
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DOI：
10.1186/1550-2783-9-37
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发表时间：
2012-08-02
影响因子：
5.1
通讯作者：
Steinacker JM
中科院分区：
文献类型：
--
作者：
Liu Y;Lange R;Langanky J;Hamma T;Yang B;Steinacker JM
运动会引起各种生理和代谢变化，从而降低运动耐量。疲劳的潜在机制之一是“运动诱发的高氨血症”。先前的研究表明，补充氨基酸可以提高训练耐力。α-酮酸是氨基酸的生化类似物，可以通过转氨作用转化为氨基酸，从而降低细胞氨水平。本研究采用双盲、安慰剂对照的方法，探讨补充α-酮酸（KAS）对运动耐力、运动效果和应激恢复状态的影响。33名未经训练的年轻男性成年人接受了为期四周的训练（5次/周;在个人无氧阈值下跑步30分钟，然后进行3 x 3分钟短跑/每次）。在为期4周的训练和1周的恢复期间，受试者每天服用α-酮戊二酸（AKG组，0.2 g/kg/d，n = 9）、支链酮酸（BCKA组，0.2 g/kg/d，n = 12）或等热量安慰剂（对照组，n = 12）。AKG组第4周的训练量、最大输出功率和肌肉扭矩均高于对照组（分别为175 ± 42 min，412 ± 49 W和293 ± 58 N米，P<0.05）和BCKA组与对照组（92 ± 70，381 ± 67，233 ± 43）比较，P<0.05。训练3周后，对照组的总应激和情绪衰竭评分显著升高（P<0.05），而KAS组的总应激和情绪衰竭评分无显著性差异。在KAS下，受试者可以承受更大的训练量，达到更高的功率输出和峰值肌肉扭矩，并伴随着更好的应激恢复状态。因此，KAS提高了运动耐力和训练效果，沿着具有更好的应激恢复状态。KAS对训练耐力的改善是否与对氨稳态的影响有关，需要进一步观察。
Exercise causes a variety of physiological and metabolic changes that can in turn reduce exercise tolerance. One of the potential mechanisms responsible for fatigue is “exercise-induced hyperammonemia”. Previous studies have shown that supplementation with amino acids can increase training tolerance. The α-keto acids are biochemical analogs of amino acids and can be converted to amino acids through transamination, thus reducing the cellular ammonia level. This double blind, placebo-controlled study was designed to investigate the effects of α-keto acid supplementation (KAS) on training tolerance, training effect, and stress-recovery state. Thirty-three untrained young male adults underwent four weeks of training (5 sessions/week; 30 minutes running at the individual anaerobic threshold followed by 3 x 3 minute sprints/each session). Throughout the 4 weeks of training and one week of recovery, subjects took α-ketoglutarate (AKG group, 0.2 g/kg/d, n = 9), branched-chain keto acids (BCKA group, 0.2 g/kg/d, n = 12) or isocaloric placebo (control group, n = 12) daily. The 4th week training volume, maximum power output and muscle torque were higher in the AKG group (175 ± 42 min, 412 ± 49 Watts and 293 ± 58 Newton meters, respectively, P<0.05) and the BCKA group (158 ± 35, 390 ± 29 and 273 ± 47, P<0.05) than in the control group (92 ± 70, 381 ± 67 and 233 ± 43). The general stress and emotional exhaustion as assessed by the rest-stress-questionnaire-sport after the 3rd week of training increased significantly in the control group (P<0.05), but not in the KAS groups. Under KAS, subjects could bear a higher training volume and reach a higher power output and peak muscle torque, accompanied by a better stress-recovery-state. Thus, KAS improves exercise tolerance and training effects along with a better stress-recovery state. Whether the improved training tolerance by KAS is associated with effects on ammonia homeostasis requires further observation.