An increasing number of research studies point to participation in endurance exercise training as having significant detrimental effects upon reproductive hormonal profiles in men. The means used for prevention and correction of fatigue are ineffective for sexual function recovery and have contraindications and numerous side effects. The search for substances effectively restoring body functions after overtraining and at the same time sparing the reproductive function, which have no contraindications precluding their long and frequent use, is an important trend of studies. One of the candidate substances is ribose used for correction of fatigue in athletes engaged in some sports.We studied the role of ribose deficit in metabolism of the testes under conditions of excessive exercise and the potentialities of ribose use for restoration of the endocrine function of these organs.45 male Wistar rats weighing 240±20 g were used in this study. Animals were divided into 3 groups (n=15): control; excessive exercise; excessive exercise and received ribose treatment. Plasma concentrations of lactic, β-hydroxybutyric, uric acids, luteinizing hormone, total and free testosterone were measured by biochemical and ELISA methods. The superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glucose-6-phosphate dehydrogenase activities and uric acids, malondialdehyde, glutathione, ascorbic acids, testosterone levels were estimated in the testes sample.Acute disorders of purine metabolism develop in rat testes under conditions of excessive exercise. These disorders are characterized by enhanced catabolism and reduced reutilization of purine mononucleotides and activation of oxidative stress against the background of reduced activities of the pentose phosphate pathway and antioxidant system. Administration of D-ribose to rats subjected to excessive exercise improves purine reutilization, stimulates the pentose phosphate pathway work, inhibits oxidative stress of the testes, and saves the testicular endocrine function.