Reliability of Using Motion Sensors to Measure Children's Physical Activity Levels in Exergaming.

OBJECTIVES: This study examined the reliability of two objective measurement tools in assessing children’s physical activity (PA) levels in an exergaming setting.

METHODS: A total of 377 children (190 girls, Mage = 8.39, SD = 1.55) attended the 30-min exergaming class every other day for 18 weeks. Children’s PA levels were concurrently measured by NL-1000 pedometer and ActiGraph GT3X accelerometer, while children’s steps per min and time engaged in sedentary, light, and moderate-to-vigorous PA were estimated, respectively.

RESULTS: The results of intraclass correlation coefficient (ICC) indicated a low degree of reliability (single measures ICC = 0.03) in accelerometers. ANOVA did detect a possible learning effect for 27 classes ( p < 0.01), and the single measures ICC was 0.20 for pedometers. Moreover, there was no significant positive relationship between steps per min and time spent in moderate-to-vigorous physical activity (MVPA). Finally, only 1.3% variance was explained by pedometer as a predictor using Hierarchical Linear Modeling to further explore the relationship between pedometer and accelerometer data.

CONCLUSIONS: The NL-1000 pedometers and ActiGraph GT3X accelerometers have low reliability in assessing elementary school children&rsquo;s PA levels during exergaming. More research is warranted in determining the reliable and accurate measurement information regarding the use of modern devices in exergaming setting.