THE SECULAR TREND IN MOTOR-SKILL ABILITIES OF GIRLS WITH A VARIED RATE OF BIOLOGICAL MATURATION

The aim of the study was to describe generational changes in the rate of puberty and motor skills of nonmenstruating and menstruating girls from eastern Poland in the years 1986–2016. The research material consisted of the results of 11,700 girls from eastern Poland. Physical fitness was assessed by means of the International Physical Fitness Test. Based on the test answers regarding the date of the first menstruation, using the "status quo" method, the fraction of already menstruating girls in relation to all the studied female students, as well as the mean age of the menarche were calculated. The differences in the results between the individual stages of the research were estimated using the t-Student test for independent samples. In the analyzed thirty-year timeframe, in the eastern part of the country, the percentage of menstruating girls in relation to non-menstruating girls increased significantly, while the menarche age decreased. In non-menstruating girls, an improvement in the results of hand strength, torso strength and agility was observed, as well as a reduction in the power of the lower limbs, running endurance, speed and torso flexibility. Slight, statistically insignificant differences were found in functional strength. On the other hand, in menstruating girls the results in lower limb power, speed, running endurance, and torso flexibility had decreased. Only hand strength and torso strength results had improved. The results of functional strength and agility were at a similar level. Girls with the same calendar age, but with a different maturation rate, were characterized by similar secular trends in physical fitness. On the other hand, greater negative and smaller positive changes in the level of motor skills were found in menstruating girls.