The factors determining the state of efficiency of middle distance runners, include the adaptation of muscles to stress, which manifests as physical endurance. Training aimed at development of endurance, the mode of muscle work, the nature of the developing efforts determine the appropriate transformation in the muscles themselves, which are formed by all content of the training process. In providing the necessary level of development of endurance namely strength training has an important role to play because it is impossible to resolve the problem solely by means of cross-country athletics. From the point of view of experts, intentional use of means of accentuated influence on the neuro-muscular system will improve the sports result. With the aim of identifying features in the content of strength training of middle distance runners in the study was carried out a survey of experts (n = 21), which were provided with a list of 46 physical training means. The content of strength training was examined as well within the context of analysis of the loads of this group of means, developed by runners on average distances at SISS. The study analyzed the records of 14 coaches. The results of the analysis have allowed identifying the most frequently used means and methods of strength training of middle distance runners aged 13-15 years.