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.