There are close associative relationships between physical and mental development of a person, and it has been established that systematic exercise has a positive effect on physical and mental performance. The purpose of the study is to identify the possibility of a specific effect of training loads of different orientation on the indicators of mental performance of young female athletes aged 13-15 years. The features of specific influence of training loads of different orientation on indicators of mental performance of young sportsmen of specialized boarding sports institutions are considered. The sportswomen of Brovary sports professional college (experimental group) (n=75) took part in the research, who according to the classification of sports by Dembo (1980) were divided into two groups: group A - speed and power sports (n=28); group B - endurance sports (n=47). The control group consisted of female students aged 13-15 years (n=30) who did not play sports. The mental performance of the subjects was assessed by the results of solving arithmetic problems. A comparative analysis of changes in the indicators of mental performance of the subjects is given. It is revealed that the specificity of the training process leaves an imprint on the nature of changes in the indicators of the mentioned performance in young female athletes aged 13-15 years. The orientation of the training process specializes the peculiarities of the development of mental performance of young sportsmen of adolescent age. Under the influence of training loads mainly aimed at developing the quality of endurance, there is an improvement in mental performance (there is a significant decrease in the indicator of time of solving problems and a decrease in the number of errors made during testing), while under the influence of loads of speed and power character there are insignificant changes in the average values of time of solving problems and a significant increase in the number of errors made.

Background and Study Aim. The purpose of the study is to develop and experimentally substantiate the efficiency of methods to improve the physical fitness (PF) of students in physical education classes using CrossFit means.     Material and Methods. The studies were conducted at the University with first-year students and involved 44 students of the control group and 52 students of the experimental group aged 17 to 19 years. Three versions of the experimental program to improve the students’ PF in physical education classes using CrossFit means were developed. The students’ PF level was determined according to the results of performing the State tests of the Ministry of Education and Science of Ukraine: 100 m running (s), standing long jump (cm), pull-ups and cross bar dips (number); hanging leg raises to the crossbar (number); 1000 m running (min, s); shuttle run 4x9 m and 10x10 m (s); trunk forward bending (cm). The level of students’ functional fitness was determined according to the indices of heart rate (HR), blood pressure, time of breath-holding while performing Stange’s test, lung vital capacity. Results. In the process of the pedagogical experiment more pronounced positive changes in the indices of physical and functional fitness were observed in students of the experimental group as compared to those of the control group, the functional reserves of the heart and motor system of students increased by the end of the experiment. The efficiency of four-hour classes a week according to the experimental program manifested itself in the increase of strength, strength endurance, speed and agility during a performance of motor tests; a decrease in resting heart rate, an increase of the degree of HR increment under load (relative to the resting level), an increase of HR recovery at the first minute after the load. Mathematical models of interrelations of separate somatic and vegetative parameters in the process of development and improvement of motor skills under the influence of the experimental program of physical education with the use of CrossFit means were developed and specified. Mathematical models reflect mechanisms of increase of functional reserves of heart and motor system of students, their interrelation in the process of improving the results in motor tests under the influence of CrossFit means. Conclusions. The results of the research confirm the higher efficiency of the physical education experimental method with the use of specially developed complexes of CrossFit® physical exercises in comparison with the generally accepted program of the Ministry of Education and Science of Ukraine. The efficiency of the experimental program’s impact on the physical state of the students is confirmed by an increase in the level of development of motor qualities, an increase in the economy of the body functioning at rest, an increase in the functional reserves of the heart and the motor system.