This diploma thesis is written about the impact of physical and extra physical activity to the characteristics and motor skills, but also on the health of children of primary school age. In this research, on a sample of 47 third grade schoolgirls dealing in additional physical activity that is practicing basketball in the section of school sports societies and involved only in the regular teaching physical education, evaluated the anthropometric measures and motor skills. The results showed that schoolgirls engaged with additional physical exercise have better results in motor skills, as well as a noticeable increase in muscle mass. All additionally collected research of different authors are analyzed and summarized, and based on them, it is concluded about the impact of physical activity on the development and improvement of motor skills of school children. Children and young people spend their leisure time doing activities that require minimal physical activity. Wiewing at this problem from the kinesiology point of view, leisure time must be subordinated to movement and exercising, as it is known that that exercise can affect a large ammount of a human characteristics. The increase in health problems among children in primary school is associated with the lack of excercise and outdoor activities, and also because of the poor quality of kinesiology culture teaching.