BACKGROUND: Metabolic protectors containing (Mexicor, Cytoflavin, Metaprot Plus) or not containing (Emoxipin, Riboxin, Metaprot) succinate in their structure showed a sufficiently high clinical efficacy in eliminating or reducing the asthenic symptom complex in athletes with overtraining.
 AIM: The aim of the study was to develop the principles of rational pharmacological correction of asthenic symptom complex in high performance athletes using succinate-free and succinate-containing metabolic protectors (Mexicor, Riboxin/Cytoflavin, Metaprot/Metaprot Plus).
 MATERIALS AND METHODS: The study included 104 high-class athletes of various specializations, which was conducted during the period of the athletes training camps in the pre-competitive period. Due to the high physical and mental stress in the pre-competition period and the focus on competitive selection for responsible international competitions, a short (15 days) study period was used. The maximum loads in athletes were achieved by the end of the 7th day of training, followed by stabilization of the loads and its optimization by the 15th day. The work was performed in compliance with all the rules of evidence-based medicine and ethical standards of work (obtaining informed consent, randomization, the use of a double-blind placebo-controlled method of treatment, valid methods of statistical evaluation).
 RESULTS: The course prescription of succinate-containing metabolic protectors during the period of preparation for competitions had a favorable effect on the restoration of high functional indicators, which is confirmed by an objective assessment of the functional state of athletes, data from biochemical studies of metabolism (carbohydrate, protein and fat), as well as the oxidative status of athletes. In the groups of athletes who received metabolic protectors, recovery was more active than in the placebo group, this was especially noticeable in the groups that received Metaprot plus, Metaprot and Сytoflavin, to a lesser extent Мexicor and Riboxin. In the latter case, the indicators in the stress tests of Stange and Gench were not fully restored, which was also reflected in the reduced Bogomazov index. It is important to emphasize that the indicators of physical endurance (PWC170) reached the values of the initial period, which indicates the optimization of loads under the influence of metabolic agents.
 CONCLUSIONS: The most effective in restoring the functional state of high-class athletes are succinate-containing metabolic agents (Metaprot plus, Cytoflavin, Mexicor) and to a lesser extent (in comparison with them) drugs that do not contain succinic acid (Riboxin, partly Metaprot). LPO indicators, initially somewhat elevated in athletes, showed a tendency to normalize under the influence of the appointment of metabolic protectors. Almost all studied preparations showed activity according to these tests, although the most pronounced positive changes were registered after the appointment of Мetaprot plus, Мetaprot and Сytoflavin. Mexicor and Riboxin were somewhat less active in all studied parameters.