McMurray RG, Harrell JS, Bradley CB, Webb JP, Goodman EM. Comparison of a computerized physical activity recall with a triaxial motion sensor in middle-school youth. Med Sci Sports Exerc 1998 Aug;30(8):1238-45.


PURPOSE: To develop and test a computerized activity recall (CAR) for capturing activity and energy expenditure (EE) in youth and to further our understanding of the use of the three-dimensional accelerometer (Tritrac) for studying activity and EE. METHODS: Forty-five students (25 girls and 20 boys) in grade 6-8, completed 5 consecutive days of the CAR and were randomly assigned to wear the Tritrac during 1 day in which they also completed the CAR. Twenty-two subjects also repeated 5 d of the CAR and 1 d of Tritrac monitoring 1-2 wk later. RESULTS: The correlation between CAR and Tritrac for total EE was significant (r = 0.510, P = 0.0003). However, the total EE computed from the Tritrac was significantly greater than the CAR (1941 +/- 273 kcal vs 1576 +/- 343 kcal (8.14 +/- 1.14 vs 6.60 +/- 1.44 MJ); P < 0.001). The EE of activities was similar for the Tritrac and CAR, approximately 670 kcal (2.80 MJ), suggesting that the difference between the two methods was their estimates of resting EE. Comparison of the CAR and Tritrac for classifying active and inactive subjects indicated that both methods similarly classified 35 of the 45 subjects or 78% (P = 0.0038). Although significant, the Kappa statistic (kappa = 0.398) indicated a low-level of agreement between methods. The Tritrac indicated 50.4 +/- 29.2 min.d-1 of activities of > or = 3 METs, whereas the CAR indicated 76.7 +/- 71.9 min.d-1 (P = 0.02). The week 1 vs 2 test-retest correlation was 0.0485 (P = 0.022) for the Tritrac and 0.820 (P = 0.0001) for the CAR. CONCLUSIONS: It appears that both methods have acceptable reliability. However, the validity of each method to measure total and activity EE remains unclear, as the Tritrac appears to overestimate resting energy expenditure, whereas the CAR overestimates total minutes of activity.

Full Text

The full text is available at https://dx.doi.org/10.1097/00005768-199808000-00009

At A Glance

Individual Physical Activity Behavior Variables

Total Energy
Sedentary Activity
Total Physical Activity/Physical Activity Level


Individual Physical Activity Behavior

Measure Type


Electronic monitor (e.g., accelerometer, pedometer, heart rate)

Measure Availability

Not reported

Number of Items

Not applicable

Study location



a single year-round middle school


Not applicable

Information about Development of Measure

Nothing to add

Study Design

Study Participants


6 - 11 Years

12 - 18 Years






Black/African American


Predominantly Low-income/Low-SES


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

Quantitative data on study sample

Data Reported on SES

Not applicable

SES-related Variables

Not applicable

How To Use


Who Administered



How Administered

Direct observation, PC/PDA/GPS unit

Time Required

Not reported

Training Required

Not reported

Instructions on Use

Not reported

Data Analysis

Data Collection/Analysis Costs

Not available

Data Collection/Protocol

Not available

Instructions on Data Analysis

Not reported

Validity (0)

There are no validity tests reported for this measure.

Reliability (3)

Type of reliability Construct/subscale assessed Test/statistic used Result
Test-retest See paper
Test-retest CAR total energy expenditure Intraclass correlation 0.947
Test-retest CAR activity energy expenditure Intraclass correlation 0.820