The aim of this study was to compare the
oxygen cost of running in boys with and without
Developmental Coordination Disorder (
DCD). Fourteen boys with
DCD (9.1 ± 1.4 yr) and 16 typically developing (TD) controls (9.4 ± 1.3 yr) were tested on two separate occasions at least a week apart. On the first visit, motor proficiency, body composition and maximal aerobic capacity were established. On the second visit, oxygen consumption was determined via indirect calorimetry while participants ran at three submaximal speeds (7.2 km/h, 8.0 km/h and 8.8 km/h) on a motorised treadmill for 4 min each. Additional physiological responses such as blood
lactate, respiratory exchange ratio (RER), heart rate,
salivary alpha amylase and pain threshold were monitored at baseline and after each submaximal effort. Although there were no differences in the
oxygen cost of running at all three speeds, the boys with
DCD had higher blood
lactate concentration (7.2 km/h, p=0.05; 8.0 km/h p=0.019), heart rate (p ≤ 0.001), RER (8.0 km/h, p=0.019; 8.8 km/h, p=0.001),
salivary alpha amylase (8.0 km/h, p=0.023; 8.8 km/h, p=0.020) and a lower pain threshold (p<0.01). The higher overall metabolic cost of running in boys with
DCD as indicated by the higher RER, heart rate and blood
lactate concentrations, together with the higher levels of sympathoadrenal medullary activity and sensitivity to
pain, may be deterring factors for participation in physical activity in this population.