Survey of Synergistic Effect of L-carnitine with Glutamine on Body Composition and Dietary Intake in Soccer Players: A Double-blind, Randomized Clinical Trial

Background: The present study was conducted to investigate the possibleeffects of L-carnitine and glutamine and their synergistic effects on malesoccer athletes. Methods: 28 male soccer players (21.1 ± 0.7 y) wereenrolled in a randomized pre and post intervention, double-blind design.Before the intervention, their performances were assessed by Bruceprotocol, and their body composition was measured with the bodycomposition analyzer. Then, athletes were randomly allocated into fourgroups: 2 g L-glutamine, 2 g L-carnitine, 2 g L-carnitine + 2 g L-glutamineand placebo. Supplements were prescribed for 21 days and after threeweeks, athletes performances and body composition were re-evaluated.Results: The results showed that body weight, body fat percentage, leanmuscle mass, and dietary intake made no significant changes in differentgroups of athletes. In between groups comparison, results did notsignificantly change in any performance indices. However, in L-carnitinesupplement group, the results of pre and post intervention showed that therunning distance and maximal oxygen uptake (VO2max) increasedsignificantly while the subjective sense of fatigue decreased significantly.Conclusions: Based on our findings, a three-week prescription ofseparateor combined glutamine and L-carnitine, had no effects on bodycomposition or dietary intake in soccer players. But, the athletes energyintake was more than the one reported in other studies. Although furtherstudies are required to assess these effects on athletic performance.

Keywords:

L-carnitine , L-glutamine , Body composition , Dietary intake , Soccer , Performance