Measurement of effect of L-carnitine by ergospirometry Summary The intention is to determine the effect of L-carnitine on fatty acid metabolism. Values like volume of utilized oxygen, performance and respiratory quotient were chosen for evaluation. The study is a randomized and placebo-controlled. The testing was performed on a treadmill with gas sensing device Cortex Metalyzer 3B and sporttester Polar RS 400. The measurement was adjusted compared to the pre-set test program. The reason was detecting a change in fatty acid metabolism, which takes place under aerobic conditions and starts later. Participants were recreational and performance athletes. Paired t-test and percentage change were used for evaluation. There was no change in the volume of utilized oxygen, performance and respiratory quotient. This study does not match with the majority of similar trials, which indicate the reduction of the respiratory quotient, reduced lactate levels, markers of increased oxidation of fatty acids and the other markers of aerobic metabolism.

This work deals with the determination of L-carnitine in food supplements. L-carnitine is a substance naturally occurring in organism, essential for metabolism of fatty acids. In food supplements is used especially for reducing body weight as a "fat burner". L-carnitine is popular with athletes for improve athletic performance. While data are not available to support these positive effects of carnitine, the positive results of carnitine supplementation in the medicine were found, mainly on cardiovascular system. The literary part of this study describes the properties and the use of carnitine in the diet of human. Furthermore, a review of methods used for determination of L-carnitine in variety of samples is mentioned. In the experimental section the efficiency of SPE method for preparation matrix of real samples was investigated. A cation exchange solid phase extraction seems to be the most effective. The optimal conditions for isolation of L-carnitine by SPE extraction were not developed. L-carnitine was determined in six various food supplements by reverse phase chromatography with UV/VIS detection.