The Validity of Heart Rate and Accelerometry in the Assessment of Physical Activity in Pre-School Children

Abstract

The purpose of this study was to validate heart rate recording (Polar Vantage XL), and accelerometry (Tritrac-R3D) against a direct observational technique (BEACHES) in the assessment of physical activity in 49 healthy male and female pre-schoolers (3.0 to 5.9 yrs). Activity was assessed in a controlled laboratory environment and in 2 field trials during spontaneous uncontrolled activity. During the laboratory session, subjects wore a heart rate monitor and an accelerometer while performing a choreographed routine of activities. The actual level was coded concurrently on the BEACHES scale by a trained observer. The three measures were significantly correlated during the laboratory (r = 0.76-0.85) and field (r = 0.50-0.85) conditions. There was no difference in mean scores for activity level of the group between two different days of field observation, however, there was considerable intra-subject variability as reflected by the low to moderate rank order correlations for all techniques. It was found that a measurement interval of greater than 5 min would likely increase the correlations. These findings suggest that the three measures of PA provide similar information about the level of PA in both a controlled and the free play environment, and pre-school children as a group generally maintain a similar level of activity from day to day.