ZeSplash2 uses a tri-axial accelerometer to detect your movements.
The data are analysed in order to count the number of steps done and deduct the amount of calories burnt and the distance you have performed given the characteristics of the profile of the user (weight, age, gender and height).
Be advised, ZeSplash2 can count a few steps even if you are not doing any activity, if you are driving on a bumpy road, or if your arms are in movement (because it is equipped of a motion sensor).
Thanks to these information (height, weight, age and gender), ZeSplash2 can calculate an estimation of the total calories burnt according to your metabolism and your activities. As for the podometer and distance functions, the calories count starts at midnight.