title: Comparison of the TriTrac-R3D accelerometer and a self-report activity diary with heart-rate monitoring for the assessment of energy expenditure in children.
abstract: Determining total energy expenditure (EE) in children under free-living conditions has become of increasingly clinical interest. The aim of this study was to compare three different methods to assess EE triaxial accelerometry (TriTrac-R3D; Professional Products, Division of Reining International, Madison, WI, USA), activity diary and heart-rate (HR) monitoring combined with indirect calorimetry (IC). Twenty non-obese children and adolescents, aged 5.5 to 16.0 years, participated in this study. Results from the three methods were collected simultaneously under free-living conditions during the same 24 h schoolday period. Neither activity diary (5904 (sd 1756) kJ) nor the TriTrac-R3D (6389 (sd 979) kJ) showed statistical differences in 24 h total EE compared with HR monitoring (5965 (sd 1911) kJ). When considering different physical activity (PA) periods, compared with HR monitoring, activity diary underestimates total EE during sedentary periods (P<0.001) and overestimates total EE and PA-EE during PA periods (P<0.001) because of the high energy cost equivalence of activity levels. The TriTrac-R3D, compared with HR monitoring, shows good agreement for assessing PA-EE during PA periods (mean difference +0.25 (sd 1.9) kJ/min; 95 % CI for the bias -0.08, 0.58), but underestimates PA-EE and it does not show good precision during sedentary periods (-0.87 (sd 1.4) kJ/min, P<0.001). Correlation between the vector magnitude generated by the TriTrac-R3D accelerometer and EE of activities derived from HR monitoring is high. When compared with the HR method, the TriTrac-R3D and activity diary are not systematically accurate and must be carefully used for the assessment of children's EE depending on the purpose of each study.
authors.affiliation: Unité de Gastroentérologie, Hépatologie et Nutrition, Clinique de Pédiatrie, Hôpital Jeanne de Flandre, and Faculté de Médecine, Lille, France.
authors.forename: G
authors.initials: G
authors.lastname: Rodriguez
authors.forename: L
authors.initials: L
authors.lastname: Béghin
authors.forename: L
authors.initials: L
authors.lastname: Michaud
authors.forename: L A
authors.initials: LA
authors.lastname: Moreno
authors.forename: D
authors.initials: D
authors.lastname: Turck
authors.forename: F
authors.initials: F
authors.lastname: Gottrand
mesh_terms: D000293:Adolescent; D002153:Calorimetry, Indirect / Q000379:methods; D002648:Child; D002675:Child, Preschool; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007702:Kinetocardiography / Q000379:methods; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods; D005082:Physical Exertion / Q000502:physiology*; D011996:Records