Research quarterly for exercise and sport

Effects of supplemental GAKIC ingestion on resistance training performance in trained men.

PMID 23930551


Glycine-arginine-alpha-ketoisocaproic acid (GAKIC) is a relatively new supplement that athletes and fitness enthusiasts ingest to enhance performance during anaerobic exercise. Therefore, the purpose of this study was to investigate the potential ergogenic effects of GAKIC ingestion during multiple bouts of resistance exercise. Seven resistance-trained men participated in a randomized, counterbalanced, double-blind study. Participants were randomly assigned to placebo or GAKIC (10.2 g) and performed 5 sets of 75% of 1-repetition maximum leg press to failure. Total load volume was calculated by multiplying the 75% of 1-repetition maximum mass lifted by the sum of repetitions to failure. One week later, participants ingested the other supplement (placebo or GAKIC) and the same exercise protocol was performed (i.e., crossover). Blood lactate, glucose, and heart rate were determined preexercise and immediately postexercise. GAKIC supplementation significantly increased leg-press total load volume (GAKIC = 31,564 +/- 9,132 kg; placebo = 25,763 +/- 6,595 kg, p < .05). Heart rate and blood lactate were significantly increased (p < .05) postexercise compared with preexercise but were not significantly different between GAKIC and placebo. No significant changes (p > .05) were detected for one-repetition maximum and blood glucose. These novel findings suggest that GAKIC increases total work performed during repeated bouts of lower-body resistance exercise. Thus, our data suggest that GAKIC ingestion before weight training may increase the training volume of athletes and resistance-trained individuals.