The Determination of Acute Oral L-Carnitine Ingestion on Physiological and Biochemical Parameters Related with Lipids in Endurance Exercise

BACKGROUND AND OBJECTIVE: Despite an abundance of literature, describing the basic mechanisms of action of L-carnitine, there remains some uncertainty regarding the effects of supplementation on fatty metabolism in healthy subjects. The purpose of this investigation was to determine the effects of acute oral L-carnitine supplementation on fat metabolism responses and endurance performance. METHODS: In this semi experimental study, thirty-four healthy male subjects consist of two experimental (n=17) and control (n=17) group performed a submaximal exercise protocol on cycle ergometer (PWC170) in two separate stages. In first stage, exercise protocol performed without L-carnitine or placebo (Lactose) supplementation. In second stage, exercise protocol performed with acute L-carnitine or placebo supplementation (3g, 90 minute before exercise). Blood samples were taken immediately after exercise protocol for analyze and calculation plasma concentrations of free fatty acid, triglyceride and the other fat metabolism indexes (LDL, HDL, TC, Lipase (and then two groups were compared.FINDINGS: The finding showed that there were no significantly differences between pre and posttest in plasma concentrations of free fatty acid (0.69±0.24 versus 0.72±0.14 mg/dL and triglyceride (158±46 versus 155±47 mg/dL. The rest and exercise heart rate and VO2max was 36±11 versus 35±9 mL/min. CONCLUSION: The mitochondrial transport of free fatty acid does not increase by L-carnitine supplementation. Collectively, L-carnitine supplementation would be unlikely to be associated with change in fat-carbohydrate metabolism in healthy people and its not influence in improving of endurance performance.