Reference charts for the six-minute walk test in healthy school-aged children from the city of Zaragoza, Spain

Introduction

The six-minute walk test is a stress test that provides information about exercise tolerance in chronic diseases. The aim of the study was to develop reference equations with normal values for the test in healthy children aged 6–12 years in our paediatric reference population.

Patients and methods

The six-minute walk test was carried out in a sample of 236 healthy children, analyzing pre- and post-test variables, and we developed reference equations selecting variables that turned out to be significant (P < .05).

Results

The pre- and post-test values, respectively, were 97.82% (SD, 0.64) vs 97.82% (SD, 0.59) for oxygen saturation; 96.59 bpm (SD, 16.11) vs 131.89 bmp (SD, 22.64) for the heart rate; 0.52 (SD, 0.83) vs 3.01 (SD, 2.42) for the degree of dyspnea (Borg scale) and 0.68 (SD, 0.98) vs 2.95 (SD, 2.26) for the degree of lower extremities fatigue (Borg scale). The average distance walked was 668.03 m (SD, 87.36) (671.42 m in boys [SD, 92.2] vs 664.22 m in girls [SD, 81.81]). We fitted predictive equations that included the variables age, height and difference between baseline and final heart rate. We also generated percentile charts of the distance walked for height.

Conclusions

Age, height, regular physical activity and obesity had an impact on test results. Obtaining reference values for the 6-min walk test in healthy children is necessary for its application in clinical practice.