Introduction: Measuring physical activity in children is a challenge as they behave with very peculiar patterns of movement, and also struggle to remember previous activity patterns over long
periods of time. Also, the objective physical activity measurement tools available are expensive and not always suitable for research where resources are restricted. Knowing that PA is an important
cardio-protective behaviour, and considering the current epidemic of obesity, there is a need to develop a practical, cheap, and child-appropriate tool for the measurement of PA. For this reason, the
REALITY (Rowett Energy intake and Lifestyle Internet Tool for You) was developed. This is an online diary that measures PA data from children. The purpose of the present study was to establish
validity evidence for the REALITY web tool.
Methods: In this project, 35 children completed the REALITY diary every day for seven days. Also, as a validation parameter, an objective measure was used for comparison: the
Actigraph accelerometer. The Actigraph is a uniaxial accelerometer, which was worn during waking hours during the 7 consecutive measurement days.
The accelerometer data were compared with the REALITY results in 3 aspects of movement: time spent in sedentary behaviour, moderate PA, and vigorous PA. Accelerometer data were processed using two
sets of cut points (Freedson and Puyua). A physical activity MET Compendium was used to give levels of Energy Expenditure for each of the PA performed by the children that were recorded in the
REALITY tool. For the statistical analysis repeated measures ANOVA and Bland Altman plots were performed.
Results: There were no differences between REALITY estimates of physical activity and Freedson Actigraph estimates of activity. There were significant differences between REALITY
estimated PA and Puyua estimates of activity. Bland Altman plots indicated good agreement between REALITY PA and Freedson Actigraph activity.
Conclusion: The REALITY tool provides accurate estimates of weekly PA levels among children and may be used with confidence in settings where access to objective measures is