Intensity and duration of activity bouts decreases in healthy children between 7 and 13 years of age: a new, higher resolution method to analyze StepWatch Activity Monitor data.

Assessment of physical, ambulatory, activity using accelerometer-based devices has been reported in healthy individuals across a wide range of ages, as well as in multiple patient populations. Many researchers who utilize the StepWatch Activity Monitor (SAM) rely on the default settings for data collection and analysis. A comparison was made between the standard output from the SAM software, and a novel method to evaluate all walking bouts using an Intensity-Duration-Volume (I-D-V) model in healthy children aged 7-13. 105 children without impairment wore the SAM for a total of 1691 d. Statistically significant differences were seen between 7-8-9 year olds and 10-11-12 year olds using the I-D-V model that were not seen using the standard SAM software default output. The increased sensitivity of this technique could be critical for observing the effect of various interventions on patients who experience physical limitations. This new analytical model also allows researchers to monitor activity and exercise-type behavior in a way which coincides with exercise prescription by assessing intensity, duration and volume of activity bouts.