Effects of acute L-carnitine supplementation on nitric oxide production and oxidative stress after exhaustive exercise in young soccer players

Abstract

Aim. The aim of this study was to investigate the effect of acute L-carnitine supplementation at two different doses on nitric oxide (NO) production and oxidative stress after exhaustive exercise. Methods. The subjects were 26 healthy males aged 17-19 years. Subjects were randomly divided into two groups of 13 each and received 3 or 4 g L-carnitine via a glass of fruit juice. After 1 h, the treadmill test was started at a speed of 8 km/h, afterwards increasing the speed 1 km/h every 3 min with a 1 min rest before every speed increase until exhaustion. Venous blood samples were collected again within 5 min following the exercise test. One week later, the test was repeated on the same athletes with placebo fluids. All subjects received a placebo via a glass of fruit juice. 1 h after the same exercise protocol mentioned above was performed and blood samples were drawn immediately. These plasma samples were used for measurement of nitrate-nitrite (NOx), which are known to be the stable end products of NO, TBARs as a lipid peroxidation indicator and an antioxidant glutathione (GSH) levels. Results and conclusion. The results of this study have shown that L-carnitine applied at a 3 g dose provides strong antioxidant action by increasing the GSH and NOx level and decreasing the TBARs level.