Physical activity has a positive influence on many aspects of our general health. A healthy attitude towards physical activity develops before the age of twelve. An active lifestyle during childhood helps prevent obesity in teenagers and adults. It can also reduce morbidity and mortality in adulthood. This paper presents guidelines on regular physical activity for healthy children and adolescents, since the latest results demonstrate a decline and differences in physical activity among Slovenian children. Our aim is to show how often and with what intensity children should be physically active.