EQOL Journal (2018) 10(1): 29-34 ORIGINAL ARTICLE 29 Health-related fitness in preschool children: Difference between organized and unorganized physical activity Dragana Zarić 1 • Zoran Gojković 2, 3 • Goran Sporiš 4 • Dejan Madić 5 ✉ Received: 12 th November, 2017 DOI: 10.31382/eqol.180603 Accepted: 15 th January, 2018 © The Author(s) 2018. This article is published with open access. Abstract The aim of this research was to determine the differences in health-related fitness between preschool children involved in organized and unorganized physical activities. This study was performed on a sample of 220 healthy preschool children that were divided into two groups, organized physical activity group (N=99) and unorganized physical activity group (N=121). Beside the set of anthropometric variables children were tested for Standing broad jump, Classic sit- and-reach test, Bent arm hang, Sit-ups in 30 seconds and Handgrip strength test. The t-test applied to determine differences between anthropometric characteristic revealed differences for almost all variables (p≤0.05). Moreover, the organized physical activity group showed better results in all fitness variables compared to unorganized group (p≤0.01). It can be concluded that the developmental gymnastics program has influence on improvement of health-related fitness in preschool children. Keywords motor abilities • children • differences • assessment Introduction The main health-related fitness components in youth are cardiorespiratory fitness, musculoskeletal fitness and motor fitness (Ortega, Ruiz, Castillo, & Sjöström, 2008). Having in mind that physical fitness is important for the current and future health in youth, (Ruiz et al., 2009) reliable and valid measures of fitness are crucial for longitudinal studies. Muscular strength and flexibility, are fitness components that are largely responsible for a children's good postural status. One study found that reduced hamstring flexibility is a risk factor for the hamstring muscle injuries (Witvrouw et al., 2001). Therefore, it is of vital importance to measure and improve health-related fitness in children. However, the development of fitness in children is influenced by individual differences during maturation. For example, in a sample of children of the same age, some children are higher and heavier, and have greater power and greater VO2max than those who are late in maturing (Malina & Katzmarzyk, 2006). Beside physical fitness, physical activity is very important for children because of the associated benefits to physical, social and psychological health (Strong et al., 2005). It was stated that children with better motor skill proficiency have 10% - 20% bigger chance of participating in vigorous physical activity (Ali, Pigou, Clarke, & McLachlan, 2016). Accordingly, previous research identified positive effect on health outcomes in youth population (Roth, 2010; Bun- ✉ dekimadic@gmail.com 1 Primary Health Care Center “Novi Sad”, Novi Sad, Serbia 2 Faculty of Medicine, University of Novi Sad, Serbia 3 Clinical Center of Vojvodina, Novi Sad, Serbia 4 Faculty of Kinesiology, University of Zagreb, Croatia 5 Faculty of Sport and Physical Education, Novi Sad, Serbia