Zacharogiannis, E., Paradisis, G., Kolifa, M., Gerakaki, M., Smirniotou, A., & Rousopoulos, V. (2009). The effect of oral L-arginine supplementation on leg speed, anaerobic capacity, and muscular strength. A paper presented at the 14th Annual Congress of the European College of Sport Science, Oslo, Norway, June 24-27.

"L-arginine is widely used by athletes as an ergogenic aid to improve physical performance for three main reasons: 1) its role in the increase of the secretion of growth hormone; 2) as a precursor for creatine synthesis, and 3) its most important role as a precursor for the biosynthesis of nitric oxide who serves as a messenger to trigger blood vessel dilation and increase blood flow. However, only little information on its real efficacy is available from controlled studies."

This study evaluated the effects of prolonged supplementation of L-arginine on 35-m performance time, anaerobic capacity, and leg knee extensors' and flexors' maximal power, and explosive leg strength using a double blind placebo-controlled trial. Healthy sprint and endurance trained Ss (M = 9; F = 7) performed a running anaerobic speed test, knee extensors' and flexors' maximal power test, and a vertical jump to evaluate leg explosive strength before and after the intake of L-arginine (3 gm/day) or a placebo for a period of three weeks.

After supplementation, 35-mperformance time significantly improved (decreased) 2.85% compared with 0.35% improvement in the placebo group. The fatigue index (% speed change between first and sixth sprint) did not change significantly after L-arginine supplementation compared to the placebo group. No significant differences were observed between groups in body composition, leg-extensors' maximal power, leg-flexors' maximal power, or explosive leg strength.

Implication. L-arginine supplementation appears to influence positively sprinting ability but does not influence body composition, anaerobic capacity, or leg power and strength measures.

Return to Table of Contents for this issue.