Assessment of physical fitness and exercise tolerance in children with developmental coordination disorder

Children with developmental coordination disorder (DCD) have been shown to be less physically fit when compared to their typically developing peers. The purpose of the present study was to examine the relationships among body composition, physical fitness and exercise tolerance in children with and without DCD. Thirty-seven children between the ages of 7 and 9 years participated in this study. Participants were classified according to results obtained on the Movement Assessment Battery for Children (MABC) and were divided in 2 groups: 19 children with DCD and 18 children without DCD. All children performed the following physical fitness tests: The five-jump test (5JT), the triple-hop distance (THD) and the modified agility test (MAT). Walking distance was assessed using the 6-min walking test (6MWT). Children with DCD showed higher scores than children without DCD in all MABC subscale scores, as well as in the total score (p<0.001). Participants with DCD were found to perform significantly worse on the MAT (p<0.001), the THD (p<0.001) and 5JT (p<0.05). Moreover, children with DCD had poorer performance on the 6MWT than children without DCD (p<0.01). Our results found significant correlations among body mass index (BMI), THD (r=0.553, p<0.05), 5JT (r=0.480, p<0.05) and 6MWT (r=0.544, p<0.05) only in DCD group. A significant correlation between MAT and 5JT (r=-0.493, p<0.05) was found. Similarly, THD and 5JT (r=0.611, p<0.01) was found to be correlated in children with DCD. We also found relationships among 6MWT and MAT (r=-0.522, p<0.05) and the 6MWT and 5JT (r=0.472, p<0.05) in DCD group. In addition, we found gender specific patterns in the relationship between exercise tolerance, explosive strength, power, DCD, and BMI. In conclusion, the present study revealed that BMI was indicative of poorer explosive strength, power and exercise tolerance in children with DCD compared to children without DCD probably due to a limited coordination on motor control.