The aim of this study was to obtain accelerometer count cut points that correspond to physical activity performed at moderate (3-5.99 METs), vigorous(6-8.99 METs) and very vigorous (≥9 METs) activity in school aged children. Subjects were 80 (41 F, 39 M) youths ranging in age from 6 to 18 years. The students performed treadmill walking and running at 3 different speeds at 0 grade, randomly assigned, for 5 min, with a 5 min rest between speeds. Data collected included the average of the last 2 min for VO2 in liters per min and counts per min from a CSA single-plane monitor worn on the right hip. A regression equation had been calculated predicting METs from counts and age. The equation had been validated with 50 and cross-validated with 30 of the subjects and then rerun with the total 80 students. The final equation was used to calculate counts from a given MET value and age. For students <12 years old, the energy expenditure was ≥3.8 METs for the lowest speed and counts were not calculated. For other ages, counts were determined for 3 METs, and for all ages for 6 and 9 METs. For a 6 year old, cut points were 2100 for 6 METs and 5392 for 9 METs. For a 12 year old, cut points were 527 for 3 METs, 3719 for 6 METs and 6910 for 9 METs. For an 18 year old, 2146 for 3 METs, 5338 for 6 METs, and 8529 for 9 METs. These cut points should be useful to both practitioners and researchers who wish to examine attainment of national physical activity standards in youth.
B-35 SLIDE PHYS ACT ASSESS IN CHILDREN