title: Calibration of ActiGraph GT3X, Actical and RT3 accelerometers in adolescents.
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.
authors.affiliation: a Department of Physical Education , State University of Londrina , Londrina , Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Romanzini
authors.forename: Edio Luiz
authors.initials: EL
authors.lastname: Petroski
authors.forename: David
authors.initials: D
authors.lastname: Ohara
authors.forename: Antonio Carlos
authors.initials: AC
authors.lastname: Dourado
authors.forename: Felipe Fossat
authors.initials: FF
authors.lastname: Reichert
mesh_terms: D061725:Accelerometry / Q000379:methods*; D056044:Actigraphy / Q000379:methods; D000293:Adolescent; D002138:Calibration; D002648:Child; D015444:Exercise; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory / Q000379:methods*; D009068:Movement; D005082:Physical Exertion; D012372:ROC Curve; D057185:Sedentary Behavior; D013686:Telemetry