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 .
Validity of physical activity monitors during daily life in patients with COPD
Symptoms during physical activity and physical inactivity are hallmarks of chronic obstructive pulmonary disease ( COPD ) . Our aim was to evaluate the validity and usability of six activity monitors in patients with COPD against the doubly labelled water ( DLW ) indirect calorimetry method . 80 COPD patients ( mean±sd age 68±6 years and forced expiratory volume in 1 s 57±19 % predicted ) recruited in four centres each wore simultaneously three or four out of six commercially available monitors vali date d in chronic conditions for 14 consecutive days . A priori validity criteria were defined . These included the ability to explain total energy expenditure ( TEE ) variance through multiple regression analysis , using TEE as the dependent variable with total body water ( TBW ) plus several physical activity monitor outputs as independent variables ; and correlation with activity energy expenditure ( AEE ) measured by DLW . The Actigraph GT3X ( Actigraph LLC , Pensacola , FL , USA ) , and DynaPort MoveMonitor ( McRoberts BV , The Hague , the Netherl and s ) best explained the majority of the TEE variance not explained by TBW ( 53 % and 70 % , respectively ) and showed the most significant correlations with AEE ( r=0.71 , p<0.001 and r=0.70 , p<0.0001 , respectively ) . The results of this study should guide users in choosing valid activity monitors for research or for clinical use in patients with chronic diseases such as COPD . This study vali date s six activity monitors in the field against indirect calorimetry ( DLW ) in patients with COPD
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 .