ABSTRACT
Exercise in high altitude and hypoxia decreases aerobic power and increases oxidative stress and lactic acid. Due to the metabolic and antioxidant properties of L-Carnitine, the purpose of this study was to investigate the effect of short-term L-Carnitine supplementation on endurance performance and cell damage in acute hypoxia. For this purpose, 16 active men after VO2max measurement in normoxia were divided into 2 groups of supplement and placebo. Supplement group received L-Carnitine and placebo group received placebo [sugar] for 10 days [3 g every day]. After eight days of supplementation period, VO2max in hypoxia condition was determined as well as normoxia. Then 1 day after supplementation, individuals participated in submaximal test [60%VO2max for 1 hour]. Blood samples were taken before, immediately after and 1 hour after recovery for determining lactic acid, lactate dehydrogenase [LDH], creatin kinase [CK] and malondialdehyde [MDA]. The result showed that short-term supplementation with L-Carnitine had no effect on VO2max [p=0.83], respiratory exchange ratio [RER] [p=0.314] and lactic acid, but it caused significant decrease in LDH [p=0.001], CH [p=0.001] and MDA [p=0.001] after submaximal activity. It can be concluded that short-term supplementation of L-Carnitine doesn't influence VO2max and lactate, but it may decrease cell damage.