Moderate and vigorous physical activity intensity cut-points for the Actical accelerometer

J Sports Sci. 2011 May;29(8):783-9. doi: 10.1080/02640414.2011.557744.

Abstract

Accelerometry is increasingly used as a physical activity surveillance device that can quantify the amount of time spent moving at a range of intensities. This study proposes physical activity intensity cut-points for the Actical accelerometer. Thirty-eight volunteers completed a multi-stage treadmill protocol at 3, 5, and 8 km · h⁻¹ (2, 3.3, and 8 METs) while wearing Actical accelerometers initialized to collect data in 60-s epochs. Using a decision boundary analytical approach, moderate and vigorous physical activity intensity cut-points were derived for the Actical accelerometer. In adults (n = 26), the cut-point for moderate physical activity intensity occurred at 1535 counts per minute and the vigorous cut-point occurred at 3960 counts per minute. In children (n = 12), the cut-point for moderate physical activity intensity occurred at 1600 counts per minute and the vigorous cut-point occurred at 4760 counts per minute. Improved classification of physical activity intensity using the decision boundary cut-points was observed compared with using mean values for each protocol stage. The cut-points derived are recommended for use in adults. The cut-points derived for children confirm the findings of previous studies.

MeSH terms

  • Actigraphy / instrumentation*
  • Adolescent
  • Adult
  • Anthropometry
  • Canada
  • Child
  • Exercise Test
  • Humans
  • Middle Aged
  • Monitoring, Physiologic / instrumentation*
  • Physical Exertion / physiology*
  • Surveys and Questionnaires
  • Young Adult