Introduction:
Physical activity is very important for the proper mental and physical development of children and youths, especially for the development of the locomotor system. The students of music schools are a unique group of children and youths, because of specific loads on the organs of locomotion, associated with the playing of musical instruments. They can therefore be exposed to a variety of health problems, particularly in the case of insufficient physical activity.

Objective:
The aim of the presented study was to assess the level of physical activity of music schools' students on weekdays and weekends against the parameters of physical efforts beneficial to health.

Material and Methods:
The study involved 225 musicians from the Katowice School of Music, Complex of I and II degrees, aged 10-18 years(138 girls and 87 boys). The level of physical activity was assessed on the basis of moderate to vigorous rates (MVPA).

Results:
Both on weekdays as well as at the weekends, boys presented a higher level of physical activity of at least moderate intensity (MVPA), which also resulted in a greater total weekly pro-health physical activity. Both boys and girls dedicated significantly more time to beneficial pro-health efforts physical health at weekends (p<0.01). The percentage of young musicians who meet accepted (in this study) standards for the optimal amount of physical activity in both groups was dramatically low (3.6% of girls and 11.5% of boys).

Conclusions:
Both boys and girls from the music schools often undertake moderate to vigorous physical activity (MVPA) at the weekends. The boys more often than the girls made pro-health physical efforts of moderate and high intensity.