ILLES BALEARS, Spain—Supplementation with a combination of citrulline-malate may enhance the body’s use of branched chain amino acids during exercise, according to a new study (Eur J Appl Physiol. ePub 25 May 2010. DOI: 10.1007/s00421-010-1509-4). Researchers from the University of Balearic Islands randomly assigned 17 male pre-professional cyclists to receive 6 g L-citrulline-malate or placebo two hours prior to participating in a 137-km cycling stage. Blood samples were taken at baseline, 15 minutes after the race, and three hours post-race.
Plasma concentrations of most essential amino acids were significantly decreased from baseline after exercise; however, most non-essential amino acids were significantly up. Ingestion of citrulline-malate significantly increased plasma concentrations of citrulline, arginine, ornithine, urea, creatinine and nitrite, and significantly decreased isoleucine concentrations after exercise from baseline measurements. Insulin levels significantly increased after exercise in both groups, as did growth hormone levels, with a slightly higher increase in the supplemented athletes. The researchers concluded L-citrulline-malate supplementation enhanced the body’s use of amino acids during exercise, as well as the production of arginine-derived metabolites.
