Effects Of L-arginine Supplementation On Pre And Post Maximal Exercise Inflammatory Response

Abstract

PURPOSE: To determine if varying acute doses of l-arginine supplementation pre-exercise has an immediate effect on pre-exercise and post-exercise inflammatory response. METHODS: Twenty five male subjects were given oral supplementation of the amino acid l-arginine 30 minutes prior to performing a maximal exercise test. Blood draws were taken pre-supplementation, post-supplementation/pre-exercise, and post exercise. Treatments included a 3 g dose (LD), a 6 g dose (HD) of l-arginine, and a placebo (PLA) for the control trial. A complete blood count was performed, using white blood cells (WBC) as a marker of inflammatory response. Linear regression was tested to determine if acute treatment accounted for a significant proportion of unique variance in WBC. RESULTS: The results showed an overall significant difference between treatments (p=0.031). LD began at a higher WBC count but had a smaller increase in WBC count over time. HD and the PLA started near the same baseline level with a near identical slope and increase of time. The linear regression of the treatment shows time interaction to account for significant proportion of unique variance in WBC count. When taken as unique significance factors the LD treatment and time interaction was found to be significant (p=0.048). PLA and HD treatment were not found to be significant over time. Regardless of supplementation amount or usage, WBC count increased post-exercise. WBC count decreased following supplementation, but before exercise. A maximal dose response was also observed, as the best result was seen with the LD while the HD and PLA were similar. CONCLUSIONS: For the subjects tested, an acute low dose supplementation of l-arginine decreased inflammatory response. A higher dose did not augment the decrease. Future studies might investigate chronic supplementation or the optimal acute supplementation.