Effects of one dose L-arginine supplementation on vasodilatation and exercise performance

ABSTRACTEFFECTS OF ONE DOSE L-ARGINE SUPPLEMENTATION ONVASODILATATION AND EXERCISE PERFORMANCEThe aim of the study was to determine the effect of oral L-Arginine (l-arg) supplementationon the vasodilatation, aerobic performance, hemodynamics and biochemical measures ofyoung footballer males administrated 6 g of l-arg on a daily basis in period of 7 days. In thisstudy, 24 volunteer male university students aged average 23±1.89 years old participated.Maximal oxygen consumption values of the subjects were determined by using QueensCollege Step Test. Subjects were randomly divided into three groups of l-arg, placebo andcontrol. After one week of 6 g l-arg supplementation, systolic blood pressure (SBP), diastolicblood pressure (DBP) and mean arterial pressure (MAP) were significantly decreased (p<.05)(SBP: from 120±5.88 to 109±11.40; DBP: from 67±5.45 to 64±5.70; MAP: from 85±3.16 to78±5.70 mmHg,). Also plasma urine level (U), maximal oxygen consumption (maxVO2),femoral artery peak systolic velocity (PSV) and end diastolic blood velocity (EDV) and vesseldiameter (D) were significantly increased (p<.05) (U: from 26.37 ± 3.62 to 29.25 ± 4.13mg/dL; maxVO2 : from 78.30±5.54 to 82.40±4.63 ml/kg-1dk-1; PSV : from 51.02 ± 4.91cm/sto 56.36 ± 5.94cm/s; EDV: from 7.36 ± 2.08 to 12.60 ± 2.23 cm/s; C: from 9.21 ± 0.27 to 9.53± 0.36 mm) in the group taking l-arg compared with the placebo group. However there wereno statically significant changes observed in any of these items in placebo and control groups.In resting heart rate, HDL, LDL and triglyceride levels, there were no statistically significantdifferences in all groups (p>.05). As a conclusion, l-arg supplementation increased theendothelium dependent vasodilatation, U, PSV, EDV, maxVO2 and decreased the SBP andDBP of young footballer males significantly (p<.05). However there were not any statisticallysignificant changes in resting heart rate, cholesterol and triglycerides levels (p>.05).Keywords: L-arginine, aerobic performance, vasodilatation, blood pressure, blood flow, urine,cholesterol