Effect of L-Carnitine Supplementation during Exercises on Blood Fatigue and Energy Metabolism Factors: A Systematic Review and Meta‐analysis of Randomized Controlled Trials

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Yongzhen Zhu
Qiaoliang Wang
Mohammad Hossein Rahimi


L-Carnitine; lactate; fatigue; glucose; energy metabolites; meta-analysis


Background: Probably L-Carnitine can induce the reduction of lactate production and improvements of performance due to the long chain fatty acid oxidation reinforcement. According to this, the aim of this review was to assess the effects of L-Carnitine consumption on blood lactate and glucose.

Methods: Scopus, Medline and Google scholar systematically searched up to April 2021. The Cochrane Collaboration tool used for the quality of studies. Random effects model, weighted mean difference (WMD) and 95% confidence interval (CI) applied for the overall effect estimating. The heterogeneity between studies evaluated applying the chi-squared and I2 statistic.

Results: The outcomes showed a significant effect of L-Carnitine supplementation on reducing lactate (weighted mean difference [WMD] = -0.65 mmol/L; 95% CI: -0.86, -0.43; P <0.001)). In addition, a subgroup analysis indicated a significant reduction in lactate concentrations, according to some of follow-ups post exercise, all dose of L-Carnitine and duration of studies, both aerobic and anaerobic exercise type, both trained and untrained participant and trials using L-Carnitine supplementation type.

Conclusions: These results showed that L-Carnitine supplementation can reduce fatigue and improve performance of aerobic and anaerobic exercise.

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