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

No abstract

Background This study aimed to investigate whether better physical fitness in kindergarten predicts later healthier body composition in first grade at school. Methods Body composition was assessed by skinfold thickness measurements. Physical fitness tests included 20 m shuttle run test, handgrip strength test, standing long jump test, 4x10 m shuttle run test as part of PREFIT fitness test battery, and one-leg stance test from EUROFIT test battery. The participants of this study were 147 Estonian children (51% boys) aged 6–8 years, who were measured in the transition from kindergarten to school. Results After adjusting for maternal body mass index, educational attainment, child’s sex, age at the measurements, greater cardiovascular and motor fitness, relative lower body strength, static balance at 6.6 yr were associated with lower fat mass index, fat mass percentage at 12-month follow-up. The relative lower body strength above the median at 6.6 yr were related to lower fat mass index and fat mass percentage at 12-month follow-up, while the static balance test results demonstrated the opposite associations. Improvements in the 4x10 m shuttle run test results during the 12-month follow-up period were associated with the most beneficial changes in body composition status, such as increases in fat-free mass index and decreases in fat mass index, fat mass percentage, waist-to-height ratio after adjusting for maternal body mass index, educational attainment, child’s sex, age, at the measurements and baseline values of exposures. Conclusion Better physical fitness tests results at 6.6 yr in kindergarten generally predicted lower body fat parameters in children at 7.6 yr in first grade at school.