Effect of Oral L-arginine Supplementation on Lactic Acid and Maximal Oxygen Consumption in Healthy Males
Abstract (Summary)The purpose of this study is to investigate the effects of varying doses of oral L-arginine supplementation on platelet aggregation, lactic acid, and nitric oxide synthase in normal health male subjects and the consequent results on maximal oxygen consumption. The hypothesis of this study is that with treatment of oral l-arginine supplementation, there will be a differential response of VO2max and lactic acid accumulation concentrations with varying doses. In order to test this hypothesis, subjects will be administered varying doses of l-arginine supplement or placebo and then will complete a VO2max test. Prior research has focused on the effects of IV or orally administered arginine and its subsequent enzymatic reduction by nitric oxide synthase to nitric oxide (NO) to benefit patients with hypercholesterolemia, hypertension, and heart disease. However, l-arginine supplementation has not been validated in terms of its cardiovascular effect in healthy populations although it has been studied for weight training. The benefits of using this supplement in cardiovascular training may be related to NO formation which has been shown to dilate blood vessels. Lactic acid accumulation may be delayed or reduced because of better oxygen delivery. Should these effects be substantiated by this study, use of l-arginine as a cardiovascular endurance supplement could provide a legal and healthy way for people to condition. Previous research has demonstrated possible differential responses to l-arginine supplementation and the physiological markers listed above. These effects should cause increases in time to exhaustion and VO2max. Twenty-five healthy males between the ages of eighteen and thirty were recruited. Subjects who volunteered to participate in the research completed an informed consent and health history questionnaire and were measured for height, weight, body composition, and blood pressure. Based on the answers to the questionnaire and the measurements recorded, the subjects who qualified were allowed to continue in the study. If the potential participant answered yes to any question and/ or does not fall within acceptable quantified limits, they were disqualified from the study. The three quantified items on the Health history questionnaire are alcohol consumption ( 30% body fat, due to an increased chance of a cardiac event, have a resting blood pressure > 140 mm/Hg systolic and > 90 mm/Hg, again due to an increased chance of a cardiac event. Females were also were excluded because of potential variations on markers from the menstrual cycle. To provide rationale for any differential responses, the physiological markers of lactic acid was evaluated. This was measured via finger sticks to produce 0.5 ml of blood at three different points of time during the testing process. The first of the finger sticks occurred upon arrival at the testing facility before any supplementation (l-arginine high dose [6 g], low dose [3 g], or placebo) is administered. The second took place 25 minutes post-supplementation, while the subject was still at rest. Testing via a VO2max test then occurred, upon completion of the testing procedure, the third and final finger stick was performed (one minute post-test). Testing trials occurred on three separate occasions seven days apart.
School:The University of Akron
School Location:USA - Ohio
Source Type:Master's Thesis
Date of Publication:06/09/2009