Metabolic accommodation of young children to treadmill walking

Few data exist concerning the reproducibility of stable oxygen uptake (VO2) values during level treadmill walking in young able-bodied children. To address this issue, 41 able-bodied 6-year-olds (19 boys, 22 girls, X HEIGHT=117.2±4.7 cm, X body MASS=21.8±2.5 kg) were tested on two occasions. In session 1, subjects were familiarized with the laboratory environment and performed 5 min of level treadmill walking at 1.34 m s−1. During session 2, each child completed 30 min (three 10-min trials) of level treadmill walking at 1.34 m s−1. For each 10-min trial, mean VO2 was determined by averaging VO2 values obtained from analysis of two 2-min expired gas samples. While the mean VO2 for trial 1 was higher than values recorded for trials 2 and 3, effect sizes corresponding to these differences were low (≤0.16). Average within subject coefficient of variation and intraclass reliability coefficient values for VO2 across the three walking trials were 2.0±1.5% and 0.96, respectively. Viewed collectively, these results suggests that among young able-bodied children, acceptably and reproducible stable VO2 values during level treadmill walking can be obtained within 10 min if data collection is preceded by exposure to testing procedures and a brief period of treadmill walking practice.