Duration: March 2014-October 2014


Changing life style behavior including increment of physical activity is a known challenge for various populations. Lately, a lot of different activity trackers have become available for consumer use and more of these trackers are expected. These wearable activity trackers have great potential for the use for a wide range of different users,               including different patient populations. The trackers are an objective tool for feedback about one’s physical activity behavior,  and can, partly because of associated applications, serve as a motivator to improve lifestyle.
However, it’s not known yet how reliable and valid these different trackers are. Knowledge about the reliability and validity is of great importance to be able to use these trackers for research and in clinical practice.


The research question of this project is: ‘what is the reliability and validity of ten different activity trackers?’


This project is a joined project. The validity of the trackers in free-living conditions will be examined in “Sit Less Research 2.0a: validity of 10 activity trackers in measuring physical activity and sedentary behaviour”.

A subset of the participants of that study will also participate in this study, in which the test-retest reliability of the devices will be examined by two times a 30-minute walk on a treadmill. Also the validity in a standardized setting (walking at the same speed) will be examined by comparing the scores of the trackers with the steps counted by hand.


The expected output of these joined projects is a publication in a scientific journal.