Calibration of accelerometer output for children.

Department of Exercise Science, University of Massachusetts, Amherst, MA 01003, USA.
Medicine &amp Science in Sports &amp Exercise (Impact Factor: 4.46). 12/2005; 37(11 Suppl):S523-30. DOI: 10.1249/
Source: PubMed

ABSTRACT Understanding the determinants of physical activity behavior in children and youths is essential to the design and implementation of intervention studies to increase physical activity. Objective methods to assess physical activity behavior using various types of motion detectors have been recommended as an alternative to self-report for this population because they are not subject to many of the sources of error associated with children's recall required for self-report measures. This paper reviews the calibration of four different accelerometers used most frequently to assess physical activity and sedentary behavior in children. These accelerometers are the ActiGraph, Actical, Actiwatch, and the RT3 Triaxial Research Tracker. Studies are reviewed that describe the regression modeling approaches used to calibrate these devices using directly measured energy expenditure as the criterion. Point estimates of energy expenditure or count ranges corresponding to different activity intensities from several studies are presented. For a given accelerometer, the count cut points defining the boundaries for 3 and 6 METs vary substantially among the studies reviewed even though most studies include walking, running and free-living activities in the testing protocol. Alternative data processing using the raw acceleration signal is recommended as a possible alternative approach where the actual acceleration pattern is used to characterize activity behavior. Important considerations for defining best practices for accelerometer calibration in children and youths are presented.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: ABSTRACT Soini, Anne Always on the move? Measured physical activity of 3-year-old preschool children Jyväskylä: University of Jyväskylä, 2015, 131 p. (Studies in Sport, Physical Education and Health ISSN 0356-1070; 216) ISBN 978-951-39-6028-5 (nid.) ISBN 978-951-39-6029-2 (PDF) Finnish Summary Diss. This study addressed the following research questions: 1) What physical activity (PA) intensity levels and patterns exist among Finnish 3-year-old preschool children (studies I, II)? 2) Are there variations between Finland and the Netherlands in 3-year-old children’s observed PA levels and contexts in childcare (study III)? 3) Are there variations between Finland and Australia in 3-year-old children’s PA intensity levels measured with accelerometers (study IV)? In Finland, 14 childcare centres in the city of Jyväskylä participated in the study. Data were gathered on 96 three-year-old preschool children (48 boys and 48 girls) in autumn 2010, and on 94 children (50 boys and 44 girls) in winter 2011. Data were also gathered on 97 (46 boys and 51 girls) 3-year-olds from nine childcare centres in Maastricht, the Netherlands, and on 64 (33 boys and 31 girls) 3-year-olds from 13 childcare centres in Melbourne, Australia. Children’s PA intensity levels and sedentary time on five consecutive days, including childcare and homecare days was assessed with ActiGraph GT3X accelerometers. The structured Observational System for Recording Physical Activity in Children-Preschool Version (OSRAC-P) of Brown et al. (2006) was used to obtain descriptive information on the context of PA behaviours in childcare settings. Appropriate statistical analyses were performed. The 3-year-old children spent the major part of their time engaged in sedentary-level activities. During childcare attendance, only 2% of all observations were recorded as moderate to vigorous PA (MVPA). The children were observed, for the most part, in non-solitary play; however, during solitary play they showed higher levels of PA intensity. In autumn, the children were more physically active in the mornings than afternoons. No major differences were observed in PA levels between days or seasons, although levels of outdoor PA were higher in autumn than winter. The Finnish children spent significantly more time in sedentary-level activities and less time in MVPA than the Dutch children, whereas, during childcare days the Finnish children spent more time in light PA than the Australian children. The childcare setting itself plays an important part in promoting more intensive PA behaviour during early childhood. Throughout the year, children should be encouraged to spend a greater amount of their time playing outdoors, engaged in MVPA-level activities, and to minimize the time spent sitting or engaged in sedentary-level activities. Finnish childcare policy makers should take note of these findings as well as of existing international practices and guidelines that have been demonstrated to be beneficial for children’s PA behaviour and thus also health. Keywords: physical activity, sedentary time, accelerometer, direct observation, childcare centre
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the short-term efficacy of coach education on basketball players' physical activity (PA) intensity during practices. Intervention effects on players' motivation were also investigated. Randomized controlled trial. This study took place over the course of a 5-day organized youth sport (OYS) basketball program in 2 sports centres in Greater Western Sydney, Australia (September, 2013). A convenience sample of 76 players and 8 coaches were recruited. Players were girls aged 9 to 12 years. Following the first 2 days of the basketball program, coaches allocated into the intervention condition attended 2 coach education sessions where strategies to increase moderate-to-vigorous physical activity (MVPA) and decrease inactivity were discussed. Each coach education session lasted approximately 2h. Compared to the control group, players in the intervention group spent a significantly higher proportion of practice time in MVPA (mean difference [MD]=14.6%; standard error [SE]=2.2%), vigorous PA (VPA; MD=12.6%; SE=1.9%), moderate PA (MD=2.0%; SE=0.5%) and a significantly lower proportion of practice time inactive (MD=-14.5%; SE=2.3%) from baseline to follow-up. There were no significant changes in motivation from baseline to follow-up in either group. Brief coach education sessions can increase MVPA and decrease inactivity without deleterious effects on players' motivation. Also, substantial increases in VPA were found, which is an important finding because VPA has been associated with health benefits, over and above benefits accrued from lower-intensity activity. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
    Journal of Science and Medicine in Sport. 02/2015;
  • Source
    Nutrients 02/2015; 7(2):970-998. · 3.15 Impact Factor


Available from
Oct 15, 2014