To provide sex-and-age specific normative values for children and adolescents' accelerometer-determined steps/day, and peak 60-minute cadence adjusted to a pedometer-based scale.

The analysis sample was 2610 children and adolescents (1329 girls) from the 2005-2006 National Health and Nutrition Examination Survey. Accelerometer data were adjusted by eliminating steps counted when activity counts/min <500. Peak 60-minute cadence represented the 60 highest minutes of accumulated steps, averaged over monitored days. Normative data included quintile-defined categories of adjusted steps/day and peak 60-minute cadence for 7 age groups (6-7, 8-9, 10-11, 12-13, 14-15, 16-17, and 18-19 years). LMSChartmakerPro produced 10 age-group-specific smoothed curves (5 for each sex) showing the 5th, 25th, 50th, 75th, and 95th percentiles, respectively, for steps/day and peak 60-minute cadence.

Steps/day was inversely associated with age in both boys and girls. The age-associated reduction was apparent in only small decrements for boys; the girl's reduction was steeper. Boys appeared to maintain or increase their peak 60-minute cadence with increased age between 8 and 15 years of age, with a reduction apparent over the last 2 age groups investigated. The peak 60-minute cadence was more variable for girls; a similar sharp reduction (3-6 steps/min) in tandem with the steps/day was apparent between 10- to 11-year-old girls and 12- to 13-year-old girls.

We provided detailed information and normative data pertaining to steps/d and peak 60-minute cadence in US children and adolescents. Like well-known body mass index growth curves, these data may be useful for scientists and clinical practitioners.