The steady increase in the number of students with health problems underlines the relevance of research on the scientific substantiation of safe and effective parameters of fitness-classes for adolescents. The paper presents an analysis of the benefits of using fitness-technologies for managing physical condition in middle- school children. The aim of the work was to study and generalize modern approaches to the use of health-enhancing fitness- technologies in the management of adolescent girls’ physical condition. Methods: theoretical analysis of special scientific and methodological literature, generalization and systematization of the data, comparative analysis, abstraction and logical-theoretical analysis, sociological methods, methods of assessment of physical health status (the Apanasenko method), and the methods of mathematical statistics. Results of the study. The analysis of the literature data showed that the use of health-enhancing exercise for managing physical condition is a priority area of research both in the world and in Ukraine. These approaches are consistent with adolescent girls’ motivational preferences in the choice of physical activities. It was found that 78% of the surveyed schoolgirls do not participate in health-enhancing exercise activities. However, 39.9% of girls want to engage in health-enhancing exercise activities, 36% want to participate in activities with elements of sports games, and 17.2% in health-enhancing swimming. Most girls chose group classes (72%). Among the surveyed adolescents, only 20% had the moderate level of physical health, 80% had the low or lower-than-moderate level; there were no school girls with higher-than-moderate or high level of health. A significant percentage of girls (16%) who are underweight have been identified. A number of developments related to improving the level of physical condition have been reported in the literature, but in most cases they are designed for people with normal weight or overweight. However, weight deficit, which can have significant negative consequences, is especially dangerous for the adolescents’ health. Conclusions. The health-enhancing exercise programs for underweight adolescent girls were found to be insufficiently substantiated. Considering the high prevalence and negative consequences of insufficient body weight for adolescent girls, the studies focused on improving the level of physical condition and body weight in this population through the use of the means of health-enhancing exercise are seemed relevant.

The article presents data on the study of a correlation between blood groups system AB0 and Rh with the peculiarities of the development of human speed abilities. It identifies a complex of genetic markers and substantiates the possibility of using this complex in the individual prognosis of the development of human motor abilities. The study shows that individuals with 0(I) and A(II) blood groups and Rh+ have a high predisposition to the development of speed abilities.