Rodriguez G, B├ęghin L, Michaud L, Moreno LA, Turck D, Gottrand F. Comparison of the TriTrac-R3D accelerometer and a self-report activity diary with heart-rate monitoring for the assessment of energy expenditure in children. Br J Nutr 2002 Jun;87(6):623-31.


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.

Full Text

The full text is available at https://dx.doi.org/10.1079/BJNBJN2002571

At A Glance

Individual Physical Activity Behavior Variables

Total Energy


Individual Physical Activity Behavior

Measure Type

Record or log

Measure Availability

Not reported

Number of Items

Not applicable

Study location


Lille, France


Most likely in French, although it was never explicitly stated.

Information about Development of Measure

Nothing to add

Study Design

Study Participants


2 - 5 Years

6 - 11 Years

12 - 18 Years





Not reported

Predominantly Low-income/Low-SES

Not reported

Sample Size


Study Design

Design Type


Health Outcomes Assessed


Obesity Measures

Not applicable

BMI Measured or Self-reported

Not applicable


Not reported

Data Reported on Race/Ethnicity

Not applicable

Data Reported on SES

Not applicable

SES-related Variables

Not applicable

How To Use


Who Administered


Third-party administered (e.g., parent/staff)

How Administered


Time Required

24 hours

Training Required

Not reported

Instructions on Use

Not reported

Data Analysis

Data Collection/Analysis Costs

Not available

Data Collection/Protocol

Collected information from 3 tools simultaneously under free-living conditions during same 24hr school day.

Instructions on Data Analysis

Not reported

Validity (1)

Type of validity Construct/subscale assessed Criterion measure used Test/statistic used Result
Criterion 11 measures of energy expenditure Measures compared to each other Mean differences Complex results concerning validity of different measures

Reliability (0)

There are no reliability tests reported for this measure.