Table 2.

Overview of features of wearable devices used in the included studies on the effectiveness and feasibility of wearable activity trackers in youth.

Device	Location worn	Main measures	Device display	Compatibility	Sensors	Memory	Waterproof
Fitbit One	Waist	Steps, stairs, distance, calories, sleep	Yes	Personal computer, iOS, Android, Windows	Accelerometer (3 axis), altimeter	Up to 23 days	No
PAM	Waist	Physical activity score	Yes	Personal computer	Accelerometer (3 axis)	Not reported	No
SenseWear	Upper arm	Physical activity, energy expenditure, steps, sleep	No (optional display required)	Personal computer	Accelerometer (3 axis), heat flux, galvanic skin response, skin temperature, near-body ambient temperature	Up to 34 days	No
Actical	Wrist, waist, ankle	Physical activity, energy expenditure, steps	No	Personal computer	Accelerometer (omnidirectional)	Up to 194 days	Yes
Polar Active	Wrist	Physical activity, steps, calories, sleep	Yes	Personal computer, iOS, Android	Accelerometer (3 axis)	21 days (activity diary)	Yes
Polar heart rate monitor	Chest	Heart rate, calories	No	Personal computer	Heart rate	Up to 30 hours	Yes