The effectiveness of increasing the sportsmanship of junior girls in middle distance running is largely determined by the degree of management of training loads. The system of training loads of juniors and young athlete athletes is covered by the general principles of their construction, adopted in sports training, such as the systemic alternation of loads and rest, increased developmental and training effects and the balance of their dynamics, unity of progression and tendency to maximum loads, wave-like dynamics of loads. The leading position of the system for managing the preparation of runners of the athletics reserve provides that the loads should, on the one hand, be adequate to the age characteristics of girls, juniors, young athletes, and on the other, be oriented to the level characteristic of higher sportsmanship. In this case, the total volumes of training load at certain stages of long-term training should be correlated with the stage of higher sportsmanship, its first phase - the norms of loads of masters of sports.