Six-minute walk distance in overweight children and adolescents: effects of a weight-reducing program.

Objective To assess the significance of consecutive six-minute walk tests (6MWTs) during a weight reduction program. Study design Overweight children and adolescents (n = 113; mean +/- standard deviation age, 12.9 +/- 2.0 years; 64 girls) performed a standardized 6MWT at the beginning and end of an in-patient weight reduction program consisting of exercise, diet, and educational and psychological support. Their 6-minute walk distance (6MWD) was compared with age-and sex-matched normal-weight children (n = 353). Results Preintervention 6MWD averaged 93% of control subjects (631 +/- 88 m versus 675 +/- 70 m, P < .001) and increased significantly to 667 +/- 90 m (P < .001) after 27 +/- 7 days of intervention (99% of control subjects; P = .260). Participants reduced their body weight from 80.9 +/- 19.8 kg to 75.6 +/- 19.0 kg, body mass index (BMI) percentile from 98.2 +/- 2.1% to 96.8 +/- 3.8%, and BMI-standard deviation score from 2.37 +/- 0.6 to 2.13 +/- 0.6 (P < .001 for each variable). BMI-standard deviation score, height, and the change in heart rate during the 6MWT were significant independent predictors of the 6MWD at preintervention and at post intervention time points (P < .001 each). Conclusions The 6MWD increases during a weight reduction program, indicating improvement of physical fitness and decreased metabolic demand during daily activities in overweight children. The 6MWT represents a practical and reliable assessment tool for exercise performance in overweight children and adolescents. (J Pediatr 2011;158:447-51).