This study, based on the observation of children (3-5 year olds) following a program of specific physical exercises guided by music, wants to evaluate the effect of movement on body, mind and cognition. It will promote activities and experience in order to 1) build up a healthy body and a healthy mind; 2) prevent obesity as well as type 2 diabetes, and 3) to improve "the functions of the liver, muscles themselves, and (importantly) the brain," as attested by the essays edited by B. Spiegelman, which report the results of the metabolism related to people regularly practicing physical education. By taking into account the last researches about the stimuli the brain receives from a rich environment and their impact on the activation of neural plasticity, which is more elastic during childhood, this analysis aims at stressing that the hormone irisin, whose beneficial effects on our health belong to the latest studies on physical exercises, is of great help not only to build up a healthy future life, but also to cure some diseases due to age or occasional accidents.