Physical activity (PA) and physical fitness are essential for normal growth, development and general health in childhood, and are important mediators of the enhancement of health-related quality of life and cognition. 1 Childhood obesity is increasing in prevalence all over the world, 2 and as related to accompanying psychological and cardiorespiratory complications, has become a major health, psychosocial, and economic concern. 3 It has been proposed that a high level of physical fitness in childhood and adolescence is associated with lower risks of future overweight, fatness, and metabolic syndrome. 4 Physical fitness has been considered to counteract some of the adverse effects of adiposity on health. 5 Observing associations of PA and physical fitness with body composition during childhood would explain the determinants of PA and physical fitness in preadolescence. Accompanying the transition from early to middle childhood are substantial changes in children's educational and recreational circumstances which may affect PA levels. 6,7 It is likely that the preschool environment influences the