Glycine-arginine-alpha-ketoisocaproic acid improves performance of repeated cycling sprints.
OBJECTIVE
The purpose of this study was to determine the effect of glycine-arginine-alpha-ketoisocaproic acid (GAKIC) supplementation on repeated bouts of anaerobic cycling performance.


METHODS
Ten men completed a randomized, double-blinded, placebo-controlled exercise protocol of two sessions separated by 7 d. Plasma lactate was analyzed in blood collected 45 min before exercise (REST) and 5 min postexercise (POST). Subjects consumed either 11.2-g GAKIC or placebo (PLC) during a 45-min period between the REST and exercise. Mean power, peak power, and fatigue values were assessed from five supramaximal, 10-s cycle ergometer sprints, separated by 1-min rest intervals. Data were analyzed using repeated measures ANCOVA.


RESULTS
A significant treatment x time interaction (P = 0.039) was observed for the change in mean power output over the five sprints between the GAKIC and PLC treatments. Post hoc analyses revealed a greater retention of mean power (P = 0.038) between sprints 1 and 2 after GAKIC (-1 +/- 9 W) versus PLC treatment (-47 +/- 18 W). No other performance variables differed between PLC and GAKIC. POST lactate was increased (P < 0.001) above REST, but there was no difference between treatments (P = 0.936).


CONCLUSIONS
These data support an ergogenic effect of GAKIC for attenuating the decline in mean power during repeated bouts of supramaximal exercise.
Buford
Britni N
BN
Health and Exercise Sciences, Truman State University, Kirksville, MO 63501, USA.
Koch
Alexander J
AJ
D000328:Adult; D001642:Bicycling / Q000502:physiology*; D001696:Biomechanical Phenomena; D002208:Caproates / Q000008:administration & dosage / Q000494:pharmacology*; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D005080:Exercise Test; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D018763:Muscle Fatigue / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000187:drug effects / Q000502:physiology; D010919:Placebos
D002208:Caproates; D010919:Placebos; C423242:glycine-L-arginine-alpha-ketoisocaproic acid; D019344:Lactic Acid