1) Introduction and background: Football players have to train or compete in several days of a week and this intensive exercise program may not give enough time for their muscle’s rehabilitation; so the chance of muscle damage can be increased. In addition, they are susceptible to physical fatigue and impaired immune function in this intensive training program.
2) Objectives: The purpose of this study was to examine the effects of carnitine and glutamine supplementation (2 g/d of L-carnitine with or without 2 g/ d of L-glutamine) on markers of muscle damage, muscle soreness, physical fatigue and some inflammatory indicators after physical exertion on football players.
3) Design: This study is a double blind, randomized, placebo-controlled, parallel clinical trial.
4) Setting and conduct: Before of supplementation protocol, each participant had to run on the treadmill for 30 minutes at 75% VO2max (maximal oxygen consumption) intensity. After this task, subjects were randomly allocated into four groups to receive supplements for 3 weeks. On day 22, at the end of supplementation period, all experimental procedures were repeated. Blood samples were obtained at preexercise and immediately after exercise. In addition, muscle soreness and physical fatigue was assessed at both occasions and 2 days after each exercise.
5) Participants including major eligibility criteria: Twenty-eight healthy male football players with more than 6-month training background were recruited in this study.
6) Intervention: L-carnitine, L- glutamine, L-carnitine + L- glutamine and placebo.
7) main outcome measures (variables): Physical fatigue, Creatine kinase, Aspartate amino transferase, Lactate Dehydrogenase, High sensitive C-reactive protein, Tumor necrosis factor – alfa, Interleukine – 6.