The aim of this thesis was to determine how and in what way physical activity affects the psyche of children. The paper wrote about the effect of physical activities on the overall development of children, and especially on their mental development. Namely, physical activity relieves stress, anxiety, lifts the mood and improves self-esteem and mental abilities. There is also ample evidence to tell us that physical activity contributes to the improvement and maintenance of mental abilities. Some research suggests that they program physical activities for two weeks, at least improve efficiency in decision-making, improve the processing of various information and learning abilities. The ability to direct attention, organize time, plan, and work memory can also be improved. Many of our experts warn that we have two problems that have arisen in the modern way of life. The first problem is that today’s children are too preoccupied with the digital world. For this reason, another problem arises, ie insufficient physical activity of children. Children spend a lot of time in a sitting position, which is a big challenge for today's teachers to find the best solutions to reduce. We are created to move, that is, our body is built that way. Enabling children to engage in physical activity in childhood will give them a foundation for a healthy lifestyle and the acquisition of motor skills that are essential in life. It should be emphasized to children that movement is very important, and that creation will provide various opportunities in life. Such a view in working with children will facilitate the realization that children enjoy movement and in fact what it means for their mental, physical or social development. From the earliest years, we should be encouraged to engage in physical activity, if it starts earlier, it is better, because it is faster and easier to adopt healthy habits that remain for life.