Significance: Prior research has established pedometer step count recommendations for children (6-12yrs) based on international BMI cutpoints (Cole, et al., 2000; Tudor-Locke et al, 2004). Data used to arrive at these recommendations (boys 15,000 and girls 12,000 steps•day-1) were part of an international data set of youth from Australia, Sweden, and the US. Earlier publication of these data (Vincent et al., 2003) revealed children in Sweden and Australia accumulated significantly more steps•day-1 than did their peers in the US, while US youth were significantly heavier according to BMI. Given this, the steps•day-1 recommendations developed may not be directly applicable to youth in the US since they were already shown to be less active and weigh more than their overseas peers (two-thirds of the sample). Therefore, the purpose of this study was to examine the classification specification of these recommendations in a sample of US children.
Design: Elementary students (391 boys, 490 girls, 6-12yrs) from three states (Arizona, Kentucky, Kansas) wore a pedometer (MLS-2505) for four consecutive weekdays during the Fall school year. During the four days height and weight were collected. Students were classified as healthy weight or overweight/obese according to international BMI cutpoints and as achieving or failing to achieve the sex-specific steps•day-1 recommendations (Tudor-Lock et al, 2004). True masters (TM, healthy weight and achieving steps•day-1), false masters (FM, overweight/obese and achieving steps•day-1), true nonmasters (TN, overweight/obese and not achieving steps•day-1), and false nonmasters (FN, healthy weight and not achieving steps•day-1) proportions were calculated. Correlations (r) were calculated between BMI and steps for boys and girls.
Results: For boys (girls in parentheses), 19.4% (29.2%) were TM, 7.7% (10%) FM, 45% (36.1%) FN, and 27.9% (24.7%) TN. Of the healthy weight boys (n = 252) and girls (n = 320) 69.8% and 55.3%, respectively, failed to achieve the sex-specific steps•day-1 recommendations. Of the overweight/obese boys (n = 139) and girls (n = 170) 21.6% and 28.8%, respectively, achieved the sex-specific steps•day-1 recommendations. Correlations were -.26 and -.10 for boys and girls, respectively.
Conclusions: The steps•day-1 recommendations failed to provide clear delineation between BMI classifications. This suggests that: a) the minimal steps•day-1 were set artificially high from the inclusion of two-thirds of the sample consisting of youth that demonstrated higher steps•day-1 and lower BMIs; and b) additional health markers (e.g., blood pressure) need to be examined to determine alternative steps•day-1 guidelines.