The Relationship of the PROMIS Pediatric Physical Activity Measure with Cardiorespiratory Fitness.

A The PROMIS Pediatric Physical Activity (PA) measure is a new instrument with established validity that measures a child self-report on short bouts of moderate to rigorous physical activity. The purpose of this study was to explore the relationship of the PROMIS Pediatric PA item bank with cardiorespiratory fitness and self-efficacy. The study was conducted at the Minnesota State Fair. Youth ages 8 to 18 years completed the PROMIS Pediatric PA and the Self-Efficacy for PA measures on an iPad. Participants performed 3-min step test with heart rates measured 1 min posttest. Participants (N = 182) were 53% female. The PROMIS Pediatric PA had a weak, significant negative correlation with the step test measurement = -0.23, = 0.001) and a weak, significant positive correlation with self-efficacy ( = 0.27, < 0.001). Measurements did not differ between groups by sex or age group (school-age and adolescent). Youth who were obese had significantly higher heart rates post step test ( = 0.004); BMI percentile groups did not differ in other measures. Self-report of PA and the physiologic measure of heart rate are from two related but different physical fitness domains which supports their significant but weak relationship.