A novel integrative procedure for identifying and integrating three-dimensions of objectively measured free-living sedentary behaviour

Abstract

BackgroundThe widely accepted definition of sedentary behaviour [SB] refers to any waking behaviour characterized by an energy expenditure ≤1.5 metabolic equivalents [METs] while in a sitting or reclining posture. At present, there is no single field-based device which objectively measures sleep, posture and activity intensity simultaneously. The aim of this study was to develop a novel integrative procedure [INT] to combine information from two validated activity monitors on sleep, activity intensity and posture, the three key dimensions of SB.MethodsParticipants in this analysis were initially recruited from a series of three studies conducted between December 2014 and June 2016 at the University of Leeds. Sixty-three female participants aged 37.1 (13.6) years with a body mass index of 29.6 (4.7) kg/m2 were continuously monitored for 5–7 days with the SenseWear Armband [SWA] (sleep and activity intensity) and the activPAL [AP] (posture). Data from both activity monitors were analysed separately and integrated resulting in three measures of sedentary time. Differences in Sedentary time between the three measurement methods were assessed as well as how well the three measures correlated.ResultsThe three measures of sedentary time were positively correlated, with the weakest relationship between SEDSWA (awake and <1.5 METs) and SEDAP (awake and sitting/lying posture) [r(61) = .37,p = .003], followed by SEDSWA and SEDINT (awake, <1.5 METs and sitting/lying posture) [r(61) = .58,p < .001], and the strongest relationship was between SEDAP and SEDINT [r(61) = .91,p < .001]. There was a significant difference between the three measures of sedentary time [F(1.18,73.15) = 104.70,p < .001]. Post-hoc tests revealed all three methods differed significantly from each other [p < .001]. SEDSWA resulted in the most sedentary time 11.74 (1.60) hours/day, followed by SEDAP 10.16 (1.75) hours/day, and SEDINT 9.10 (1.67) hours/day. Weekday and weekend day sedentary time did not differ for any of the measurement methods [p = .04–.25].ConclusionInformation from two validated activity monitors was combined to obtain an objective measure of free-living SB based on posture and activity intensity during waking hours. The amount of sedentary time accumulated varied according to the definition of SB and its measurement. The novel data integration and processing procedures presented in this paper represents an opportunity to investigate whether different components of SB are differentially related to health end points.

Physical Activity and Sedentary Time: Association with Metabolic Health and Liver Fat

“…Data included the following: daily average step count, total energy expenditure, active energy expenditure, and time spent in levels of PA including: sleep, lying down, sedentary (<1.5 METS), light (1.5–3 METS), moderate (3–6 METS), vigorous (6–9 METS), and very vigorous (>9 METS). A Microsoft Excel template, as previously described (30), was used to determine how sedentary time (not including sleep) was accumulated and provided information on the frequency of bouts and the time accumulated in a given bout category (<1 h: 1–5, 6–10, 11–20, 21–40, 41–60 min; 1–2 h: 61–80, 81–100, 101–120 min; >2 h: 121–140, 141–160, 161–180 min). To examine “frequently broken” periods of sedentary time, the given bout categories at the lower end (<1 h) were shorter in duration.…”

Issues in Measuring and Interpreting Human Appetite (Satiety/Satiation) and Its Contribution to Obesity

“…light, moderate, and vigorous), which has overcome a major limitation of past research. Technological advancements have also allowed for the measurement of the postural element of sedentary behaviour, and a novel integration technique with accelerometry has produced a ‘true’ objective assessment of sedentary behaviour which incorporates sleep, activity intensity, and postural dimensions [85].…”

Disentangling the relationship between sedentariness and obesity: Activity intensity, but not sitting posture, is associated with adiposity in women

“…Furthermore, we tested whether any relationships between the different measures of SB and adiposity were independent of MVPA. Utilising the methodological platform described previously [29] to combine information from two validated activity monitors using a novel integrative procedure, three measures of SB were defined by i) activity intensity (<1.5 METs), ii) posture (sitting/lying) and iii) activity intensity and posture.…”

“…Information on sleep and activity intensity (<1.5 METs) from the SWA and posture (sitting/lying) from the AP were integrated to generate a measure of SB defined by both activity intensity and posture during waking hours. The procedure for integrating data from the SWA and AP has been described in detail previously [29]. This procedure resulted in three SB outputs that were represented by SED SWA , SED AP and SED INT , when referring to data from the SWA, AP and integrated data from both activity -monitors, respectively.…”

“…It has been noted that there is no single measurement device that provides an accurate measure of both posture and activity intensity simultaneously [14,27]. To address this measurement limitation a method to integrate data from the SWA mini and AP micro was developed [29]. We demonstrated that it is possible to integrate time-stamped data from the SWA and the AP to measure SB defined by any waking behaviour with an activity intensity of <1.5 METs whilst in a seated or reclining posture.…”