%0 Journal Article
%T Improved training tolerance by supplementation with ¦Á-Keto acids in untrained young adults: a randomized, double blind, placebo-controlled trial
%A Liu Yuefei
%A Lange Rupprecht
%A Langanky Juliane
%A Hamma Thea
%J Journal of the International Society of Sports Nutrition
%D 2012
%I BioMed Central
%R 10.1186/1550-2783-9-37
%X Background 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 ˇ°exercise-induced hyperammonemiaˇ±. Previous studies have shown that supplementation with amino acids can increase training tolerance. The ¦Á-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 ¦Á-keto acid supplementation (KAS) on training tolerance, training effect, and stress-recovery state. Methods 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 ¦Á-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. Results The 4th week training volume, maximum power output and muscle torque were higher in the AKG group (175 ˇŔ 42 min, 412 ˇŔ 49 Watts and 293 ˇŔ 58 Newton meters, respectively, P<0.05) and the BCKA group (158 ˇŔ 35, 390 ˇŔ 29 and 273 ˇŔ 47, P<0.05) than in the control group (92 ˇŔ 70, 381 ˇŔ 67 and 233 ˇŔ 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. Conclusions 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.
%U http://www.jissn.com/content/9/1/37