Submaximal oxygen cost during incremental exercise in children with developmental coordination disorder

There has been minimal evidence examining the differences in submaximal aerobic power between children with and without probable developmental coordination disorder (pDCD). This is important as most activities of daily living are performed at submaximal levels. The aim of this study was to examine the oxygen cost of work (VO2) performed during an incremental exercise protocol on a cycle ergometer. Subjects with pDCD (n = 63) were matched for age and gender to 63 typically developing controls (12-13 years of age) using a nested case-control design. Motor coordination was assessed using the Movement Assessment Battery for Children. Children with pDCD had significantly lower VO2 peak values relative to controls (35.0 vs. 42.9 ml/kg/min, p < 0.0001). At the submaximal level, mixed effects modeling demonstrated that, after controlling for relative body fat, and VO2 peak, children with pDCD had consistently greater oxygen cost (VO2 ml/kg/min) compared to controls at any given exercise intensity (p = 0.0006). A significant interaction between pDCD and workload indicated that the difference in VO2 at higher workloads is greater than that at lower workloads (p = 0.0004). Children with pDCD utilize more oxygen to sustain the same submaximal workload. The implication of these findings is that children with pDCD may experience earlier fatigue than well coordinated individuals when engaging in physical activity.