Free-living accelerometer-determined time spent at or above individualized normal cadence in children by BMI-defined weight status

Purpose: The study of children’s free-living cadence (steps/min) is possible using accelerometers capable of recording minute-by-minute step data monitored over several days. The objective of this study was to determine free-living accelerometer- determined time at or above GAITRite-assessed individualized normal cadence in children categorized by BMI as normal weight, overweight, and obese.

Methods: A total of 375 children (154 boys, 221 girls; age=9.9±0.6 years; BMI=19.1±3.9 kg/m2) participating in the Baton Rouge site of the International Study of Childhood Obesity Lifestyle and Environment (ISCOLE) provided GAITRite-determined normal walking cadence and wore ActiGraph accelerometers for one week. Descriptive data included sample percent categorized as normal weight, overweight, and obese. A mixed-model ANOVA (PROC MIXED) was used to evaluate differences in GAITRite normal cadence and accelerometer-determined time above this individualized threshold between categories of BMI.

Results: 66.4% were normal weight, 16.0% were overweight, and 17.6% were obese. Children crossed the GAITRite at (M ± SE) 112.8 ± 0.9 steps/min during their normal walk (114.0 ± 1.2, 112.0 ± 1.9, and 111.0 ± 1.8 steps/min, respectively by the three BMI-defined weight categories; p=0.35). On average, 2.4±0.2 min/day was spent above individualized normal cadences (2.7 ± 0.3, 2.5 ± 0.5, and 1.5 ± 0.5 min/day, respectively by the three BMI-defined weight categories; p=0.18).

Conclusions: There was no BMI-related difference in free-living time ambulating at or above individualized walking cadence in part because all children homogenously spent very little time (on average < 3 min/day) at such cadences.