A novel method for using accelerometer data to predict energy expenditure

J Appl Physiol (1985). 2006 Apr;100(4):1324-31. doi: 10.1152/japplphysiol.00818.2005. Epub 2005 Dec 1.


The purpose of this study was to develop a new two-regression model relating Actigraph activity counts to energy expenditure over a wide range of physical activities. Forty-eight participants [age 35 yr (11.4)] performed various activities chosen to represent sedentary, light, moderate, and vigorous intensities. Eighteen activities were split into three routines with each routine being performed by 20 individuals, for a total of 60 tests. Forty-five tests were randomly selected for the development of the new equation, and 15 tests were used to cross-validate the new equation and compare it against already existing equations. During each routine, the participant wore an Actigraph accelerometer on the hip, and oxygen consumption was simultaneously measured by a portable metabolic system. For each activity, the coefficient of variation (CV) for the counts per 10 s was calculated to determine whether the activity was walking/running or some other activity. If the CV was <or=10, then a walk/run regression equation was used, whereas if the CV was >10, a lifestyle/leisure time physical activity regression was used. In the cross-validation group, the mean estimates using the new algorithm (2-regression model with an inactivity threshold) were within 0.75 metabolic equivalents (METs) of measured METs for each of the activities performed (P >or= 0.05), which was a substantial improvement over the single-regression models. The new algorithm is more accurate for the prediction of energy expenditure than currently published regression equations using the Actigraph accelerometer.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activities of Daily Living*
  • Adult
  • Aged
  • Algorithms
  • Energy Metabolism*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Models, Biological
  • Monitoring, Physiologic / instrumentation*
  • Monitoring, Physiologic / methods
  • Oxygen Consumption
  • Regression Analysis
  • Reproducibility of Results
  • Running / physiology
  • Walking / physiology