Since the beginning of civilization, people have planned their free time. Free time is defined through various definitions of many authors who point to the importance of its organization. Free time has different functions, and considering today's load of school obligations, it is important to plan it well. With the development of technology and computers, more and more time is spent by children in front of the screen. Children and adolescents lead a lifestyle where they are predominantly in the sitting position and this greatly affects their quality of life. The theoretical part of the work includes a part that talks about the historical aspect of free time, free time for school-age children and the physical activity that children engage in when they do not have any school obligations. The paper also provides an overview of previous research on the topic of children's free time and physical activity. In the research part of the work, according to the PAQ-C questionnaire for assessing the level of physical activity, a survey was conducted among elementary school children in the fifth and eighth grades. Among other things, the results also show that students engage in physical activity more than three times a week. The overall assessment of physical activity (PAQ-C Questionnaire) does not significantly differ when looking at the grade or gender of the student.