Conclusions : We conclude that there is large heterogeneity across studies in the explained variance of AEE when estimated based on accelerometry .
Background / Objectives : Activity-related energy expenditure ( AEE ) might be an important factor in the etiology of chronic diseases .
However , measurement of free-living AEE is usually not feasible in large-scale epidemiological studies but instead has traditionally been estimated based on self-reported physical activity .
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 : We conclude that there is large heterogeneity across studies in the explained variance of AEE when estimated based on accelerometry .
Background / Objectives : Activity-related energy expenditure ( AEE ) might be an important factor in the etiology of chronic diseases .
However , measurement of free-living AEE is usually not feasible in large-scale epidemiological studies but instead has traditionally been estimated based on self-reported physical activity .