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66 Results for: "Reference Research"

Nocturnal sleep-related variables from 24-h free-living waist-worn accelerometry: International Study of Childhood Obesity, Lifestyle and the Environment

  • Published on Dec. 2015

Objectives: We describe the process of identifying and defining nocturnal sleep-related variables (for example, movement/non-movement indicators of sleep efficiency, waking episodes, midpoint and so on) using the unique 24-h waist-worn free-living accelerometer data collected in the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE). Methods: Seven consecutive ...


Concurrent and predictive validity of physical activity measurement items commonly used in clinical settings– data from SCAPIS pilot study

  • Published on Sept. 28, 2015

Background: As the understanding of how different aspects of the physical activity (PA) pattern relate to health and disease, proper assessment is increasingly important. In clinical care, self-reports are the most commonly used assessment technique. However, systematic comparisons between questions regarding concurrent or criterion validity are rare, as are measures ...


Agreement of objectively measured physical activity and sedentary time in preschool children

  • Published on July 21, 2015

Objective: To determine the intra-individual agreement for objectively measured physical activity (PA) and sedentary behavior (SED) over two subsequent weeks in preschool children. Method: Ninety-one children aged 3 to 5 years (49% boys) from three preschools in Sogn og Fjordane, Norway, provided 14 consecutive days of accelerometer data (Actigraph GT3X +) during the autumn ...


Objectively measured physical activity and sedentary time in youth: the International children’s accelerometry database (ICAD)

  • Published on Sept. 17, 2015

Background: Physical activity and sedentary behaviour in youth have been reported to vary by sex, age, weight status and country. However, supporting data are often self-reported and/or do not encompass a wide range of ages or geographical locations. This study aimed to describe objectively-measured physical activity and sedentary time ...


Challenges and opportunities for measuring physical activity and sedentary behaviour in children and adolescents: What do we know and how can we improve compliance?

  • Presented on 2015

Introduction: This study examined agreement between activPAL3 (AP) and ActiGraph (AG) wrist and hip cut-points for assessing sedentary behaviour (SB) among 5-12 year-old children using direct observation (DO) as the criterion. Methods: 30 children (9.2±2.1y, 53.3% boys) wore AG on both wrists and the right hip and a thigh-mounted AP while ...


Physical activity measurement considerations: Development and validation of new algorithms for wrist worn accelerometers

  • Presented on 2015

Abstract: This investigation developed models to estimate aspects of physical activity and sedentary behavior from three-axis high frequency wrist worn accelerometer data. The models were developed and tested on twenty participants (n=10 males, n=10 females, mean age= 24.1, mean BMI = 23.9) who wore an ActiGraph GT3X+ accelerometer on their dominant wrist ...


Functional data analysis methods for physical activity measurements using accelerometers

  • Presented on 2015

Purpose: To propose a novel functional data analysis framework to fully characterize activity intensity, duration and frequency based on accelerometer data. Background: Traditional approaches reduce accelerometer data into simple summary measures, such as time and bouts in intensity categories (sedentary, light, moderate and vigorous activities). However, these approaches depend on ...


Preschool children’s moderate-to-vigorous-activity cut-points: Comparison between cutpoints based on vector magnitude and X-axis cut-points

  • Added on October 23, 2015

Abstract: The movement of preschool children happens on several planes more often compared school-aged children or adults. The accelerometers, such as Actigraphs, are used for measuring children's moderate-to-vigorous activity (MVPA), and the current models of accelerometers allow measuring movement on three different axis. To our knowledge, there is currently only ...


Empirically derived cut-points for sedentary behaviour during working and non-working hours: how important is the context in which we sit?

  • Presented on 2015

Introduction: Sedentary behaviour (SB) is associated with a number of health outcomes, independent of physical activity. Studies that have used accelerometers to define SB tend to use a <100 counts per minute (cpm) threshold to define SB across all domains; however, this cut-point was not empirically derived. It is not ...


Reliable assessment of physical activity in disease: an update on activity monitors

  • Published on Sept. 2014

Purpose of Review: Physical activity is the main determinant of variability of individual energy expenditure. Reliable assessment of the activity level of an individual provides information on energy requirement and vital health. Here, evidence is presented on the validity of methods to assess physical activity as applied in health and ...