Relationships between TriTrac-R3D vectors, heart rate, and self-report in obese children.

The TriTrac (Professional Products, Inc., Madison, WI) triaxial accelerometer and diary self report were compared with adjusted heart rates to evaluate 3 d of leisure-time activity in 35 8- to 12-yr-old obese children. Adjusted heart rates were calculated by subtracting preexercise resting heart rates from heart rates measured in the field. TriTrac and self-reported data were converted to multiples of resting metabolic rate (METs). Correlations between accelerometer METs and adjusted heart rates (r = 0.71) were significantly higher (P < 0.001) than correlations between adjusted heart rates and self-reported METs (r = 0.36) or accelerometer and self-reported METs (r = 0.38). Self-reported METs had higher mean standard errors in estimating heart rates (13.93 +/- 6.15 beats.min-1) than did accelerometer METs (10.94 +/- 5.62 beats.min-1; P < 0.001), were significantly greater than accelerometer METs (2.50 +/- 1.48 vs 1.80 +/- 1.48; P < 0.05) and systematically overestimated accelerometer METs. The anteroposterior vector accounted for 36%, and the vector magnitude score accounted for 34% of the variance in unadjusted heart rates. The mediolateral vector and vector magnitude score accounted for 69% of the variance in self-reported METs. The vertical vector did not account for variance in either unadjusted heart rates or self-reported METs. It was concluded that the TriTrac yielded a better estimate of activity in obese children than self report. In addition, the vector magnitude composite score of the TriTrac accounted for significantly more variance in both self-reported activity and unadjusted heart rates as compared with the vertical directional vector of the TriTrac.

[1]  M. Noland,et al.  The measurement of physical activity in young children. , 1990, Research quarterly for exercise and sport.

[2]  T. Baranowski,et al.  Reliability and variability of heart rate monitoring in 3-, 4-, or 5-yr-old children. , 1992, Medicine and science in sports and exercise.

[3]  S. Heymsfield,et al.  Discrepancy between self-reported and actual caloric intake and exercise in obese subjects. , 1992, The New England journal of medicine.

[4]  Bernard Gutin,et al.  Validation of the Caltrac Movement Sensor Using Direct Observation in Young Children , 1990 .

[5]  R. Klesges,et al.  A prospective study of the reliability and convergent validity of three physical activity measures in a field research trial. , 1989, Journal of clinical epidemiology.

[6]  P S Freedson,et al.  Field trial of a three-dimensional activity monitor: comparison with self report. , 1995, Medicine and science in sports and exercise.

[7]  D. Schoeller,et al.  Inaccuracies in self-reported intake identified by comparison with the doubly labelled water method. , 1990, Canadian journal of physiology and pharmacology.

[8]  James R. Morrow,et al.  Caltrac Validity for Estimating Caloric Expenditure With Children , 1992 .

[9]  Tom Baranowski,et al.  Validity and Reliability of Self Report Measures of Physical Activity: An Information-Processing Perspective , 1988 .

[10]  C B Corbin,et al.  The validity of the Tritrac-R3D Activity Monitor for the assessment of physical activity in children. , 1995, Research quarterly for exercise and sport.

[11]  R. Klesges,et al.  A validation of two motion sensors in the prediction of child and adult physical activity levels. , 1985, American journal of epidemiology.

[12]  David S. Krantz,et al.  Automated physical activity monitoring: validation and comparison with physiological and self-report measures. , 1993, Psychophysiology.

[13]  P S Freedson,et al.  Electronic motion sensors and heart rate as measures of physical activity in children. , 1991, The Journal of school health.

[14]  J. Sallis,et al.  The Caltrac accelerometer as a physical activity monitor for school-age children. , 1990, Medicine and science in sports and exercise.

[15]  A. Beckett,et al.  AKUFO AND IBARAPA. , 1965, Lancet.

[16]  K R Westerterp,et al.  Assessment of energy expenditure by recording heart rate and body acceleration. , 1989, Medicine and science in sports and exercise.

[17]  W. Dietz,et al.  Reference data for obesity: 85th and 95th percentiles of body mass index (wt/ht2) and triceps skinfold thickness. , 1991, The American journal of clinical nutrition.

[18]  F. Treiber,et al.  Validation of a heart rate monitor with children in laboratory and field settings. , 1989, Medicine and science in sports and exercise.

[19]  D. Altman,et al.  Comparing methods of measurement: why plotting difference against standard method is misleading , 1995, The Lancet.

[20]  R. Klesges,et al.  The assessment of children's physical activity: a comparison of methods. , 1987, Medicine and science in sports and exercise.

[21]  A F Roche,et al.  Bioelectrical impedance estimation of fat-free body mass in children and youth: a cross-validation study. , 1992, Journal of applied physiology.

[22]  D A Schoeller,et al.  Comparison of heart rate and physical activity recall with doubly labeled water in obese women. , 1995, Medicine and science in sports and exercise.

[23]  R. Washburn,et al.  The validity of objective physical activity monitoring in older individuals. , 1990, Research quarterly for exercise and sport.

[24]  R. Dishman,et al.  Failure to generalize determinants of self-reported physical activity to a motion sensor. , 1992, Medicine and science in sports and exercise.

[25]  A. Prentice,et al.  Techniques for the measurement of human energy expenditure: a practical guide. , 1993, International journal of obesity and related metabolic disorders : journal of the International Association for the Study of Obesity.

[26]  M. Noland,et al.  Description of the Physical Activity of Young Children Using Movement Sensor and Observation Methods , 1991 .

[27]  A M Prentice,et al.  Daily energy expenditure in free-living children: comparison of heart-rate monitoring with the doubly labeled water (2H2(18)O) method. , 1992, The American journal of clinical nutrition.

[28]  J. D. Janssen,et al.  Assessment of energy expenditure for physical activity using a triaxial accelerometer. , 1994, Medicine and science in sports and exercise.

[29]  P S Freedson,et al.  Comparison of activity levels using the Caltrac accelerometer and five questionnaires. , 1994, Medicine and science in sports and exercise.

[30]  N. L. Goggin,et al.  A comparison of grip strength and selected psychomotor performance measures in healthy and frail elderly females. , 1995, Research quarterly for exercise and sport.

[31]  J F Sallis,et al.  Compendium of physical activities: classification of energy costs of human physical activities. , 1993, Medicine and science in sports and exercise.

[32]  Patty S. Freedson,et al.  Validity of the Caltrac Accelerometer in Estimating Energy Expenditure and Activity in Children and Adults , 1991 .

[33]  J R Morrow,et al.  Caltrac versus calorimeter determination of 24-h energy expenditure in female children and adolescents. , 1994, Medicine and science in sports and exercise.

[34]  B. Simons-Morton,et al.  Validity of the physical activity interview and Caltrac with preadolescent children. , 1994, Research quarterly for exercise and sport.

[35]  W. Saris,et al.  Habitual physical activity in children: methodology and findings in health and disease. , 1986, Medicine and science in sports and exercise.

[36]  G. Somes,et al.  The accuracy of self-reports of physical activity. , 1990, Medicine and science in sports and exercise.

[37]  T. Baranowski,et al.  Evaluation of the Children's Activity Rating Scale (CARS) in young children. , 1993, Medicine and science in sports and exercise.

[38]  K. Janz Validation of the CSA accelerometer for assessing children's physical activity. , 1994, Medicine and science in sports and exercise.