Quantifying Physical Activity via Pedometry in Elementary Physical Education

Abstract

The objective of this study was to determine a pedometer steps per minute standard for quantifying the lesson time that first- and second-grade physical education students spent in moderate to vigorous physical activity (MVPA). The sample was divided into validation (N = 246) and cross-validation (N = 123) samples using the holdout technique. Using the criterion test model, steps per minute cut points were empirically and judgmentally determined. C-SOFIT systematic observation was the criterion instrument and pedometry was the predictor instrument. Data were collected from 45 physical education lessons implemented in six schools. The three-step analytic procedure of computing mastery/nonmastery outcome probabilities, phi coefficients, and error proportions was used to determine the optimal steps per minute cut point for quantifying 33.33% of the physical education lesson time engaged in MVPA within a 30 class. Steps per minute was highly correlated with observation (r = 0.74-0.86, P < 0.0001). Five steps per minute scores that were accurate indicators of 33.33% of the class time engaged in MVPA in the validation sample were accurate indicators of steps per minute in the cross-validation sample. The optimal steps per minute cut point ranged from 60.00 to 63.00, which is equivalent to 1800-1890 steps in a 30-min physical education class. Data supports the use of pedometry steps per minute values as an accurate indicator of MVPA. Pedometry demonstrates promise as a viable large-scale surveillance instrument for measuring MVPA in physical education.