CONCLUSIONS Utilizing a consumer-based wearable activity tracker as either the primary component of an intervention or as part of a broader physical activity intervention has the potential to increase physical activity participation .
BACKGROUND The range of benefits associated with regular physical activity participation is irrefutable .
Despite the well-known benefits , physical inactivity remains one of the major contributing factors to ill-health throughout industrialized countries .
Traditional lifestyle interventions such as group education or telephone counseling are effective at increasing physical activity participation ; however , physical activity levels tend to decline over time .
Consumer-based wearable activity trackers that allow users to objective ly monitor activity levels are now widely available and may offer an alternative method for assisting individuals to remain physically active .
OBJECTIVE This review aim ed to determine the effects of interventions utilizing consumer-based wearable activity trackers on physical activity participation and sedentary behavior when compared with interventions that do not utilize activity tracker feedback .
Wrist-worn accelerometers in assessment of energy expenditure during intensive training.
We assessed the ability of the Polar activity recorder ( AR ) to measure energy expenditure ( EE ) during military training . Twenty-four voluntary male conscripts participated in the study and wore an AR on the non-dominant wrist 24 h a day for 7 d. The AR analyzed and stored the frequency of h and movements ( f_h and ) into memory at 1 min intervals . The relationship between f_h and and EE was studied over a 7 d period of military training using the doubly labeled water ( DLW ) technique . In addition , the relationship between f_h and and EE was analyzed during walking and running on a treadmill with an indirect calorimeter ( IC ) , and f_h and was measured during a supervised 45 min field march test where the conscripts carried combat gear .  EE was expressed as physical activity level ( PAL ) , total energy expenditure ( TEE ) , and activity-induced energy expenditure adjusted for body mass ( AEE/BM ) . Over the 7 d period , f_h and alone explained 46 % of inter-individual variation in PAL(DLW ) . After inclusion of body height and mass in the model used to predict PAL(DLW ) from f_h and , a very high positive correlation and a low st and ard error of estimate ( SEE ) were observed between the AR and DLW techniques : for TEE r = 0.86 ( p < 0.001 ) , the SEE was 6.3 % , and for AEE/BM r = 0.84 ( p < 0.001 ) , the SEE was 12.8 % . In the treadmill exercise , f_h and correlated highly with PAL(IC ) ( r = 0.97 ± 0.02 ) . In the 45 min field march test , the AR measured similar f_h and as on the treadmill at the same speed . In conclusion , the wrist-worn AR can be regarded as a reliable and valid method for assessing EE during intensive training
CONCLUSIONS Utilizing a consumer-based wearable activity tracker as either the primary component of an intervention or as part of a broader physical activity intervention has the potential to increase physical activity participation .
BACKGROUND The range of benefits associated with regular physical activity participation is irrefutable .
Despite the well-known benefits , physical inactivity remains one of the major contributing factors to ill-health throughout industrialized countries .
Traditional lifestyle interventions such as group education or telephone counseling are effective at increasing physical activity participation ; however , physical activity levels tend to decline over time .
Consumer-based wearable activity trackers that allow users to objective ly monitor activity levels are now widely available and may offer an alternative method for assisting individuals to remain physically active .
OBJECTIVE This review aim ed to determine the effects of interventions utilizing consumer-based wearable activity trackers on physical activity participation and sedentary behavior when compared with interventions that do not utilize activity tracker feedback .