Calibration of ActiGraph GT3X, Actical and RT3 accelerometers in adolescents

Eur J Sport Sci. 2014;14(1):91-9. doi: 10.1080/17461391.2012.732614. Epub 2012 Oct 18.

Abstract

The objective of this study was to develop count cut-points for three different accelerometer models: ActiGraph GT3X, RT3 and Actical to accurately classify physical activity intensity levels in adolescents. Seventy-nine adolescents (10-15 years) participated in this study. Accelerometers and oxygen consumption ([Formula: see text]) data were collected at rest and during 11 physical activities of different intensities. Accelerometers were worn on the waist and [Formula: see text] was measured by a portable metabolic system: Cosmed K4b2. Receiver operating characteristic (ROC) curves were used to determine cut-points. Cut-points for sedentary (SED), moderate-to-vigorous (MVPA) and vigorous-intensity physical activity (VPA) were 46, 607 and 818 counts·15s(-1) to the vertical axis of ActiGraph; 180, 757 and 1112 counts·15s(-1) to the vector magnitude of ActiGraph; 17, 441 and 873 counts·15s(-1) for Actical; and 5.6, 20.4 and 32.2 counts·s(-1) for RT3, respectively. For all three accelerometer models, there was an almost perfect discrimination of SED and MVPA (ROC >0.97) and an excellent discrimination of VPA (ROC>0.90) observed. Areas under the ROC curves indicated better discrimination of MVPA by ActiGraph (AUC=0.994) and Actical (AUC=0.993) when compared to RT3 (AUC=0.983). The cut-points developed in this study for the ActiGraph (vector magnitude), RT3 and Actical accelerometer models can be used to monitor physical activity level of adolescents.

Publication types

  • Validation Study

MeSH terms

  • Accelerometry / methods*
  • Actigraphy / methods
  • Adolescent
  • Calibration*
  • Child
  • Exercise*
  • Humans
  • Male
  • Monitoring, Ambulatory / methods*
  • Movement
  • Physical Exertion*
  • ROC Curve
  • Sedentary Behavior*
  • Telemetry