Health-related Fitness in Preschool Children with and without Motor Delays

PURPOSE: School-age children with developmental coordination disorder (DCD) have poor health-related fitness (HRF), but little is known about when these deficits emerge. The purpose of this study was to determine if 4- and 5-yr-old children who meet the criteria for DCD exhibit poorer HRF compared with typically developing (TD) children, and if this relationship is mediated by vigorous physical activity (VPA) engagement. METHODS: Five hundred and ninety-two children participated (age, 5.0 ± 0.6 yr) from the Coordination and Activity Tracking in CHildren study. Motor skills were assessed using the Movement Assessment Battery for Children-2, with groups defined as having DCD (≤5th percentile), at risk for DCD (6th-16th percentile), and TD (>16th percentile). Measures of body composition included body mass index, waist circumference, and body fat percentage. Musculoskeletal fitness assessments included standing long jump distance, as well as peak and mean power assessed using a 30-s Wingate protocol on a pediatric cycle ergometer. Time to exhaustion on a progressive, treadmill test was used to determine aerobic fitness. Flexibility and VPA were assessed using a sit-and-reach test and 7-d accelerometry, respectively. RESULTS: Children in the DCD group had the poorest musculoskeletal and aerobic fitness, whereas TD children had the highest. No differences in body composition among groups were found. Daily VPA was similar among groups and did not explain HRF differences. CONCLUSIONS: Preschool children with DCD have decreased anaerobic and aerobic fitness compared with TD children; however, VPA and body composition seem to be less affected by DCD in the early years. Early motor interventions may be able to improve fitness and reduce the risk of hypoactivity and obesity as children with DCD get older.