Effects of Carnitine with and without Glutamine Supplementation on Markers of Muscle Damage and Muscle Soreness among Football Players: A Randomized Controlled Clinical Trial

Abstract

Background: Exercise-induced muscle damage can affect exercise performance. The purpose of this study is to examine the effects of Carnitine and Glutamine supplementation on markers of muscle damage and muscle soreness after physical exertion on football players.Materials and Methods: Twenty eight healthy male football players aged 21.1±0.7 were recruited in a double blind, randomized, placebo-controlled clinical trial on 3 weeks of supplementation. Before supplementation protocol, each participant had to run on a treadmill for 30 minutes at 75% VO2max. Participants were randomly divided into 4 groups: L-Carnitine, L- Glutamine, L-Carnitine plus L- Glutamine and placebo. Blood samples were obtained pre-exercise and immediately after exercise. Muscle soreness was assessed on both occasions and two days after each exercise.Results: L-Carnitine and L-Glutamine supplementation for 21 days significantly decreased Creatine Kinase activity as a marker of muscle’s damage before (P=0.014) and after exercise (P=0.047), and muscle soreness two days after physical exertion (P=0.057). However, Lactate Dehydrogenase activity was affected by Carnitine supplementation after exercise.Conclusion: Chronic oral supplementation of Carnitine and Glutamine before exercise can reduce chemical markers of muscle tissue damage after exercise. In addition, these supplements may reduce muscle pain after exercise and optimize the processes of muscle tissue repair.[GMJ. 2014;3(4):207-15]

Does l-carnitine supplementation affect serum levels of enzymes mainly produced by liver? A systematic review and meta-analysis of randomized controlled clinical trials

“…L-carnitine was orally administered and the intervention dose ranged between 500 to 4000 mg/day. For the control groups, ten trials used placebo controls (35,36,39,44,(79)(80)(81)(82)(83)(84), six trials did not prescribe any treatment (37,(40)(41)(42)(43)77), and three trials used drugs such as interferon-α, ribavirin, and entecavir, in which participants in the intervention group also received these drugs in addition to L-carnitine (38,47,78). The majority of trials included either gender, with the age ranging from 18 to 85 years.…”

“…Two trials were done in hemodialysis patients (40,41), one study included participants with hypothyroidism (44), cystic acne patients (35) and thyroid patients (80). One study was conducted in obese women (42), three trials included healthy participants (39,82,83) and one study included patients with suspected acute myocardial infraction (84). The characteristics of the included studies are detailed in Table 2.…”

“…Although the description for the random generation was well-addressed in six studies (36,38,41,44,47,78,79,82), others did not explain random sequence generation method, and one of the studies was not randomized (37). Two trials included information about allocation concealment (82,85).…”

“…Although the description for the random generation was well-addressed in six studies (36,38,41,44,47,78,79,82), others did not explain random sequence generation method, and one of the studies was not randomized (37). Two trials included information about allocation concealment (82,85). Four studies were considered to be a low risk of bias regarding blinding of participants and personnel (36,39,(79)(80)(81)(82)(83)(84)(85).…”

“…Two trials included information about allocation concealment (82,85). Four studies were considered to be a low risk of bias regarding blinding of participants and personnel (36,39,(79)(80)(81)(82)(83)(84)(85). In the majority of included trials, the blinding of outcome assessment was unclear.…”