Are current body mass index referenced pedometer step-count recommendations applicable to US youth?
BACKGROUND
The purpose of this study was to cross-validate international BMI-referenced steps/d cut points for US girls (12,000 steps/d) and boys (15,000 steps/d) 6 to 12 years of age.


METHODS
Secondary pedometer-determined physical activity data from US children (N=1067; 633 girls and 434 boys, 6 to 12 years) were analyzed. Using international BMI classifications, cross-validation of the 12,000 and 15,000 steps/d cut points was examined by the classification precision, sensitivity, and specificity for each age-sex stratum.


RESULTS
For girls (boys) 6 to 12 years, the 12,000 (15,000) steps/d cut points correctly classified 42% to 60% (38% to 67%) as meeting (achieved steps/d cut point and healthy weight) and failing (did not achieve steps/d cut point and overweight). Sensitivity ranged from 55% to 85% (64% to 100%); specificity ranged from 23% to 62% (19% to 50%).


CONCLUSIONS
The utility of pedometer steps/d cut points was minimal in this sample given their inability to differentiate among children who failed to achieve the recommended steps/d and exhibited an unhealthy weight. Caution, therefore, should be used in applying previous steps/d cut points to US children.
Beets
Michael W
MW
Department of Exercise Science, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA.
Le Masurier
Guy C
GC
Beighle
Aaron
A
Rowe
David A
DA
Morgan
Charles F
CF
Rutherford
Jack
J
Wright
Michael
M
Darst
Paul
P
Pangrazi
Robert
R
D015992:Body Mass Index; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D009765:Obesity / Q000517:prevention & control; D012016:Reference Values; D012737:Sex Factors; D014481:United States; D016138:Walking / Q000502:physiology / Q000706:statistics & numerical data*