Clinical Studies & White Papers

The following is a list of some of the peer reviewed studies on the Tritrac device, the predecessor to the RT3 Research Activity Monitor. These studies have validated the basic technology used for tracking energy expenditure using accelerometers. As more data has been gathered Stayhealthy has continued to improve upon its industry-leading algorithms. Look for additional study results to be posted in the near future.

  • Ainsworth, Barbara E.; Haskell, W. L.; Leon, A. S.; Jacobs, D. R., Jr.; Montoye, H. J.; Sallis, J. F.; Paffenbarger, R. S., Jr. (1993). Compendium of physical activities: classification of energy costs of human physical activities. Med Sci Sports Exerc, 25:71-80.
  • Chen, K.Y.; Sun, M. (1997). Improving energy expenditure estimation by using a triaxial accelerometer. J Appl Physiol, 83(6):2112-22.
  • Coleman, K. J.; Epstein, L. H. (2001). Using the TriTrac to improve self-reported activity in sedentary adult males. Accepted for presentation at 48th annual conference for the American College of Sports Medicine, May 30 - June 2, 2001. A published abstract in Med Sci Sports Exerc, 33(Suppl.).
  • Coleman, Karen J.; Epstein, Leonard H. (1998). Application of generalizability theory to measurement of activity in males who are not regularly active: a preliminary report. Res Q Exerc Sport, 69:58-63.
  • Coleman, K. J.; Saelens, B. E.; Wiedrich-Smith, M. D.; Finn, J. D.; Epstein, L. H. (1997). Relationships between TriTrac-R3D vectors, heart rate and self-report in obese children. Med Sci Sports Exerc, 29:1535-42.
  • Conn, Vicki S.; Minor, Marian A.; Mehr, David R.; Burks, Kathryn J. (2000). Recording activity in older women with TriTrac. Am J Health Behav, 24(5):370-8.
  • DeVoe, D.; Gotshall, R. (1998). Validity of the TriTrac-R3D accelerometer during backpacking: A case study. Journal of Human Movement Studies, 34(6):271-81.
  • Epstein, L. H.; Paluch, K. J.; Coleman, K. J.; Vito, D.; Anderson, K. (1996). Determinants of physical activity in obese children assessed by accelerometer and self-report. Med Sci Sports Exerc, 28:1157-64.
  • Eston, R. G.; Rowlands, A. V.; Ingledew, D. K. (1998). Validity of heart rate, pedometry and accelerometry for predicting the energy cost of children’s activities. J Appl Physiol, 84:362-71.
  • Fehling, Patricia C.; Smith, Denise L.; Warner, Sarah E.; Dalsky, Gail P. (1999). Comparison of accelerometers with oxygen consumption in older adults during exercise. Med Sci Sports Exerc, 31:171-5.
  • Freedson, Patty S.; Miller, Kelly (2000). Objective monitoring of physical activity using motion sensors and heart rate. Res Q Exerc Sport, 71(2 Suppl):S21-9.
  • Fulton, J. E.; Masse, L. C.; Tortolero, S. R.; Watson, K. B.; Heesch, K. C.; Kohl, H. W.; Blair, S. N.; Caspersen, C. J. (2001). Field evaluation of energy expenditure from continuous and intermittent walking in women. Med Sci Sports Exerc, 33(1):163-70.
  • Goldfield, G. S.; Kalakanis, L. E.; Ernst, M. M.; Epstein, L. H. (2000). Open-loop feedback to increase physical activity in obese children. Int J Obes Relat Metab Disord, 24(7):888-92.
  • Harro, Maarike (1997). Validation of a questionnaire to assess physical activity of children ages 4-8 years. Res Q Exerc Sport, 68(4):259-68.
  • Harvey-Berino, Jean; Wellman, Andy; Hood, Virginia; Rourke, Janine; Secker-Walker, Roger (2000). Preventing obesity in American Indian children: When to begin. J Am Diet Assoc, 100(5):564-6.
  • Hendelman, D.; Miller, K.; Baggett, C.; Debold, E.; Freedson, P. (2000). Validity of accelerometry for the assessment of moderate intensity physical activity in the field. Med Sci Sports Exerc, 32(9 Suppl):S442-9.
  • Jakicic, John M.; Winters, C.; Lagally, Kristen; Ho, Joyce; Robertson, Robert J.; Wing, Rena R. (1999). The accuracy of the TriTrac-R3D accelerometer to estimate energy expenditure. Med Sci Sports Exerc, 31(5):747-54.
  • Jakicic, John M.; Polley, Betsy A.; Wing, Rena R. (1998). Accuracy of self-reported exercise and the relationship with weight loss in overweight women. Med Sci Sports Exerc, 30(4):634-8.
  • Jakicic, John M.; Wing, R. R.; Butler, B. A.; Robertson, R. J. (1995). Prescribing exercise in multiple short bouts versus one continuous bout: effect on adherence, cardiorespiratory fitness, and weight loss in overweight women. Int J Obes Relat Metab Disord, 19:893-901.
  • Janz, K. F.; Witt, J.; Mahoney, L. T. (1995). The stability of children's physical activity as measured by accelerometry and self-report. Med Sci Sports Exerc, 27:1326-32.
  • Johns, David P.; Ha, Amy S. (1999). Home and recess physical activity of Hong Kong children. Res Q Exerc Sport, 70(3):319-23.
  • Kochersberger, G. A.; McConnell, E.; Kuchibhatla, M. N.; Pieper, C. (1996). The reliability, validity, and stability of a measure of physical activity in the elderly. Arch Phys Med Rehabil, 77:793-5.
  • Lappe, J. M.; Recker, R. R.; Weidenbusch, D. (1998). Influence of activity level on patellar ultrasound transmission velocity in children. Osteoporos Int, 8(1):39-46.
  • Lemmer, J.T.; Ivey, F.M.; Ryan, A.S.; Martel, G.F.; Hurlbut, D.E.; Metter, J.E.; Fozard, J.L.; Fleg, J.L.; Hurley, B.F. (2001). Effect of strength training on resting metabolic rate and physical activity: age and gender comparisons. Med Sci Sports Exerc, 33(4):532-41.
  • Leenders, N.; Sherman, W.; Nagaraja, H. (2000). Comparisons of four methods of estimating physical activity in adult women. Med Sci Sports Exerc, 32(7):1320-6.
  • Louie, L.; Eston, R. G.; Rowlands, A. V.; Tong, K. K.; Ingledew, D. K.; and Fu, F.H. (1999). Validity of heart rate, pedometry and accelerometry for estimating the energy cost of activity in Hong Kong Chinese boys. Pediatric Exercise Science, 11, 229-239.
  • Masse, L. C.; Fulton, J. E.; Watson, K. L.; Heesch, K. C.; Kohl, H. W.; Blair, S. N.; Tortolero, S. R. (1999). Detecting bouts of physical activity in a field setting. Res Q Exerc Sport, 70(3):212-9.
  • Matthews, Charles E.; Freedson, Patty S. (1996). Field trial of a three-dimensinal activity monitor: comparison with self report. Med Sci Sports Exerc. 27(7):1071-8.
  • McMurray, Robert G.; Harrell, Joanne S.; Bradley, Chyrise B.; Webb, Julia P.; Goodman, Eric M. (1998). Comparison of a computerized physical activity recall with a triaxial motion sensor in middle school youth. Med Sci Sports Exerc, 30(8):1238-45.
  • Ng, Alexander V.; Kent-Braun, Jane A. (1997). Quantitation of lower physical activity in persons with multiple sclerosis. Med Sci Sports Exerc, 29(4):517-23.
  • Nichols, Jeanne F.; Morgan, Cindy G.; Chabot, Lauren E.; Sallis, James F.; Calfas, Karen J. (2000). Assessment of physical activity with the Computer Science and Applications, Inc., accelerometer: laboratory versus field validation. Res Q Exerc Sport, 71:36-43.
  • Nichols, J. F.; Morgan, C. G.; Sarkin, J. A.; Sallis, J. F.; Calfas, K. J. (1999). Validity, reliability, and calibration of the TriTrac accelerometer as a measure of physical activity. Med Sci Sports Exerc, 31(6):908-12.
  • O'Mailia, S. P.; Williford, H. N.; FACSM; Olson, M. S.; Baldwin, S.; Duey, B.; Crumpton, S.; Lavoie, A. M. (1998). Validity of TriTrac-R3D and Caltrac: energy cost of popular aerobic exercise. Med Sci Sports Exerc, 30(5):S13.
  • Rikli, Roberta E. (2000). Reliability, validity, and methodological issues in assessing physical activity in older adults. Res Q Exerc Sport, 71(2 Suppl):S89-96.
  • Rowlands, Ann V.; Eston, Roger G.; Ingledew, David K. (1999). The relationship between activity levels, aerobic fitness, and body fat in 8-10 year old children. J App Physiol, 86:1428-35.
  • Rowlands, A. V.; Eston, R. G.; Ingledew, D. K. (1997). Measurement of physical activity in children with particular reference to the use of heart rate and pedometry. Sports Med, 24, 258-272.
  • Saelens, Brian; Epstein, L. H.; O'Brian, J. G. (1995). The TriTrac-R3D activity monitor and behavioral observation: a validity study. Ann Behav Med, 17:S113 (Abstract).
  • Sallis, James F.; Saelens, Brian E. (2000). Assessment of physical activity by self-report: status, limitations, and future directions. Res Q Exerc Sport, 71(2 Suppl):S1-14.
  • Servais, Stephen B.; Webster, John G. (1984). Estimating human energy expenditure using an accelerometer device. J Clin Eng, 9(2):159-171.
  • Sherman, W. M.; Morris, D. M.; Kirby, T. E.; Petosa, R. A.; Smith, B. A.; Frid, D. J.; Leenders, N. (1998). Evaluation of a commercial accelerometer (TriTrac-R3D) to measure energy expenditure during ambulation. Int J Sports Med, 19:43-47.
  • Steele, Bonnie G.; Holt, Lyn; Belza, Basia; Ferris, Scott; Lakshminaryan, S.; Buchner, David M. (2000). Quantitating physical activity in COPD using a triaxial accelerometer. Chest, 117(5):1359-67.
  • Strand, Brad; Walswick, Paul; Sommer, Christa (2000). Tracking children's caloric expenditure in physical education. J of Physical Education, Recreation & Dance, 71(5):35.
  • Welk, G. J.; Blair, S. N.; Wood, K.; Jones, S.; Thompson, R. W. (2000). A comparative evaluation of three accelerometry-based physical activity monitors. Med Sci Sports Exerc, 32(9 Suppl):S489-97.
  • Welk, Gregory J.; Corbin, Charles B.; Dale, Darren (2000). Measurement issues in the assessment of physical activity in children. Res Q Exerc Sport 71(2 Suppl):S59-73.
  • Welk, Gregory J.; Corbin, Charles B.; Kampert, J. (1998). The validity of the TriTrac-R3D activity monitor for the assessment of physical activity in children: II. Temporal relationships among objective assessments. Res Q Exerc Sport, 69:395-9.
  • Welk, Gregory J.; Corbin, Charles B. (1995). The validity of the TriTrac-R3D activity monitor for the assessment of physical activity in children. Res Q Exerc Sport, 66:202-9.
  • Westerterp K. R. (1999). Physical activity assessment with accelerometers. Int J Obes Relat Metab Disord, 23 Suppl 3:S45-9.