Optimal immune function is crucial for the best possible performance in elite athletes and the weekend warrior alike. Research shows that sedentary people do not have as vigorous an immune system as those who habitually exercise. However, moderate exercise has been shown to drastically improve immune response.
The primary goal of this study was to examine the effects of variable dosage of l-arginine on white blood cell count (WBC) and platelet count before and after VO2max testing of healthy males. The amount of l-arginine was also examined to determine the effectiveness of supplementation per dose.
The current study comprised of twenty-five male subjects of at least 18 years of age, but younger than 30 years of age. After the initial visit the subjects were to return for three subsequent visits, which consisted of a fasted pre-treatment blood draw upon arrival. The treatment consisted of three ounces of lemon juice, five ounces of water, one packet of lemonade flavoring, and one of the three treatments, placebo, 3g or 6g. Treatment was then given after the pre-treatment blood draw in a double blind randomly assigned order. After a 25 minute absorption period had elapsed, a second blood draw was taken. Testing then occurred, which included a VO2max test utilizing a standard Bruce Protocol on a treadmill. Upon completion of the VO2max test, a third blood draw was taken one minute post-exercise. Blood samples were later sent for a complete blood count (CBC) analysis to measure WBC and platelet count.
In this study, the level of significance was set a priori at (P < 0.05). Post-hoc analyses was performed where applicable to determine significant interactions. There was no statistically significant relationship between dose and WBC. With this information, neither the dose of 3g or 6g of l-arginine nor the placebo showed a significant alteration to WBC, thus indicating that no matter the dosage of l-arginine, there was no significant effect on WBC among the subjects. There was a statistically significant increase in WBC over time regardless of dosage from pre-exercise to post-exercise testing. There was no statistically significant relationship between treatment dose and platelet count. Neither the dose of l-arginine nor the placebo showed a significant alteration to platelet counts. There was a statistically significant change of platelet count from pre-exercise to post-exercise testing. Concluding that regardless of dosage, platelet count increased post exercise.
The study concludes that l-arginine had no significant effects on pre and post-exercise WBC and platelet count, regardless of l-arginine dosage. The study did, however, show a definitive relationship between time and both the WBC and platelet count, thus indicating and proving that exercise itself does evoke an immune response.