Sports and physical activity are extremely important needs of our organism, without which our body would not develop properly. The positive effects of children and young people playing sports provide extremely important psychological and health benefits for the proper growth and development of the child. The proper growth and development of a child is influenced by genetic and acquired environmental factors, from genetic growth factors, sex, seasonal variations, environmental conditions, race, nutrition, disease, secular growth to the social and property status of the family. The child's height and mass, as well as the degree of maturity and biological age develop and change during the child's developmental years. Motor development of infants through primitive and postural reflexes and through elementary movements of stability, movement and control of the hand develop and realize basic movements that are important for further contact with the environment and the development of motor skills from childhood until the end of growth and development. The choice of sport and the age of the child's involvement primarily depends on the developed abilities and skills, as well as on the chosen sport and its challenges. Also, when choosing, it is necessary to take into account the child's wishes, interests, personality and potential. In addition to the child, parents also play an important role in the inclusion and selection of sports activities. The most important role of the parents is the motivation of the child and perseverance and support in the chosen sports activity. The sedentary lifestyle of children and young people has become a global problem. Today, almost all children replace sports and physical activities with prolonged sitting and the use of modern technology. Long-term sitting affects the spine and posture, as well as the overweight of children and young people. Physiotherapy, as a part of medical science, plays an extremely important role in education and maintaining and improving mobility and health habits. A physiotherapist, as a health promoter, influences children and young people through education and raising awareness of the importance of activity and at the same time educates them about the harmful effects of a sedentary lifestyle.