, it is well known that school-aged children and adolescents can accumulate a substantial amount of sedentary time during school hours ( 20 , 28 ), with findings from Scotland estimating that 3.8 to 5.6 hours per day are spent being sedentary ( 42 ). Therefore, given this decline in PA levels among
Rhona Martin-Smith, Duncan S. Buchan, Julien S. Baker, Mhairi J. Macdonald, Nicholas F. Sculthorpe, Chris Easton, Allan Knox and Fergal M. Grace
Kenneth E. Powell, Abby C. King, David M. Buchner, Wayne W. Campbell, Loretta DiPietro, Kirk I. Erickson, Charles H. Hillman, John M. Jakicic, Kathleen F. Janz, Peter T. Katzmarzyk, William E. Kraus, Richard F. Macko, David X. Marquez, Anne McTiernan, Russell R. Pate, Linda S. Pescatello and Melicia C. Whitt-Glover
al. 31 TV indicates television. Sedentary time, light physical activity, and MVPA interact within a finite, 24-hour day. A heat map developed by the 2018 PAGAC committee depicts the risk of all-cause mortality associated with various combinations of sitting time (in hours) and MVPA (in minutes) (Figure
Aline Mendes Gerage, Tânia Rosane Bertoldo Benedetti, Raphael Mendes Ritti-Dias, Ana Célia Oliveira dos Santos, Bruna Cadengue Coêlho de Souza and Fábio Araujo Almeida
during the study. Only 23 VAMOS participants and 26 CG participants had validated accelerometer data at preintervention and postintervention. Table 3 Sedentary Time and Physical Activity of Both Groups at Preintervention and Postintervention VAMOS (n = 23) CG (n = 26) Effects Group Time Interaction SED
Salih A. Salih, Nancye M. Peel, Di Enright and Wendy Marshall
capacity to perform. This relationship between MBI and walking time in the community has not been reported before. Promoting PA and aiming to achieve a clinically meaningful improvement in PA level in older persons has been shown to be challenging, as it requires changing behavior to reduce sedentary time
Abigail L. Gilbert, Jungwha Lee, Madeleine Ma, Pamela A. Semanik, Loretta DiPietro, Dorothy D. Dunlop and Rowland W. Chang
Sedentary behavior is associated with increased risk of functional decline and disability. Individuals with rheumatoid arthritis (RA) spend more time sedentary than healthy adults. Self-reported assessment of sedentary behavior has not been well-developed in this patient population.
172 adults with RA wore an accelerometer for 7 days and completed a modified version of the Yale Physical Activity Survey (YPAS). YPAS-derived sedentary estimates included 1) daily sitting categories (<3, 3 to 6, 6 to 8, >8 hours/day), 2) continuous daily sedentary time calculated by subtracting hours spent sleeping or in physical activity from a 24-hour day, and 3) rank order of YPAS-derived continuous daily sedentary time. Each estimate was compared with objective accelerometer-derived sedentary time using linear regression and Bland-Altman analysis.
A significant relationship was observed between accelerometer-derived sedentary time and all 3 estimates. Bland-Altman plot demonstrated systematic bias, however Bland-Altman plot of rank-order demonstrated that the ranked YPAS-derived continuous estimate was an unbiased predictor of ranked accelerometer sedentary time though limits of agreement were wide.
This patient-reported approach using the YPAS shows promise to be a useful tool to identify the most sedentary patients. Providing a practical and accurate tool may increase the frequency sedentary behavior is assessed by clinicians.
Valerie Carson, Michelle Stone and Guy Faulkner
To make robust conclusions regarding the association between accelerometer-measured sedentary time and overweight and obesity among children, several gaps in the literature must be addressed. The purpose of this study was to examine associations between sedentary time, weekday sedentary time, weekend sedentary time, sedentary bouts, sedentary breaks, and BMI z-score among children and by low (bottom 50%) and high (top 50%) moderate- to vigorous-intensity physical activity (MVPA) participation. Results are based on 787 children aged 11 years living in Toronto, Canada. Children’s physical activity and sedentary time were objectively assessed using ActiGraph accelerometers in 2010/11. Height and weight were measured and BMI z-scores were calculated based on the World Health Organization growth standards. When participants were stratified into low and high MVPA groups, sedentary bouts of 5–9 (β = 0.22 [95% CI: 0.01, 0.43]) and 10–19 (0.30 [−0.05, 0.55]) minutes for total days were associated with BMI z-score in the low MVPA group only. Similar trends were observed with the weekday but not the weekend variables. Therefore, in addition to increasing MVPA, reducing time spent in 5- to 19-min sedentary bouts may have important implications for weight status particularly for children with lower MVPA participation during the week.
Marie-Louise Bird, Cecilia Shing, Casey Mainsbridge, Dean Cooley and Scott Pedersen
Sedentary behavior is related to metabolic syndrome and might have implications for the long-term health of workers in a low activity environment. The primary aim of this pilot study was to determine activity levels of adults working at a University during work hours. A secondary aim was to determine the relationship between actual and perceived activity levels.
Activity levels of university staff (n = 15, male = 7, age = 53 ± 7 years, BMI = 26.5 ± 2.5kg·m2) were monitored over 5 consecutive workdays using SenseWear accelerometers, then participants completed a questionnaire of their perception of workplace sedentary time.
Each participant spent 71.5 ± 13.1% (358 ± 78 min) of their workday being sedentary (< 1.5 METs), 15.6 ± 9.0% involved in light activity (1.5–3 METs), 11.7 ± 10.0% in moderate activity (3–5 METs), and 1.1 ± 1.3% in vigorous activity (> 5 METs) (P < .0001). The mean difference between actual (SenseWear < 1.5 METs) and perceived sitting time was –2 ± 32%; however, perceived sedentary time was reported with a range of under-to-over estimation of –75% to 51%.
This pilot study identifies long periods of low metabolic activity during the workday and poor perception of individual sedentary time. Interventions to reduce sedentary time in the workplace may be necessary to ensure that the work environment does not adversely affect long-term health.
Scott E. Crouter, Diane M. DellaValle, Jere D. Haas, Edward A. Frongillo and David R. Bassett
The purpose of this study was to compare the 2006 and 2010 Crouter algorithms for the ActiGraph accelerometer and the NHANES and Matthews cut-points, to indirect calorimetry during a 6-hr free-living measurement period.
Twenty-nine participants (mean ± SD; age, 38 ± 11.7 yrs; BMI, 25.0 ± 4.6 kg·m-2) were monitored for 6 hours while at work or during their leisure time. Physical activity (PA) data were collected using an ActiGraph GT1M and energy expenditure (METs) was measured using a Cosmed K4b2. ActiGraph prediction equations were compared with the Cosmed for METs and time spent in sedentary behaviors, light PA (LPA), moderate PA (MPA), and vigorous PA (VPA).
The 2010 Crouter algorithm overestimated time spent in LPA, MPA, and VPA by 9.0%−44.5% and underestimated sedentary time by 20.8%. The NHANES cut-points overestimated sedentary time and LPA by 8.3%−9.9% and underestimated MPA and VPA by 50.4%−56.7%. The Matthews cut-points overestimated sedentary time (9.9%) and MPA (33.4%) and underestimated LPA (25.7%) and VPA (50.1%). The 2006 Crouter algorithm was within 1.8% of measured sedentary time; however, mean errors ranged from 34.4%−163.1% for LPA, MPA, and VPA.
Of the ActiGraph prediction methods examined, none of them was clearly superior for estimating free-living PA compared with indirect calorimetry.
Clare Hume, Anna Timperio, Jenny Veitch, Jo Salmon, David Crawford and Kylie Ball
This study examined cross-sectional and longitudinal associations between physical activity, sedentary behavior, and depressive symptoms among adolescents.
Participants were 155 adolescents (14.4 years ± 0.61) in 2004 (40% boys). Data collection occurred in 2004 and again in 2006. At both time points, participants completed the Centers for Epidemiological Studies Depression Scale for Children (CES-DC), from which they were classified as having depressive symptoms (≥15) or not (<15). Organized sport and TV viewing were self-reported and moderate-to-vigorous (MVPA) and vigorous (VPA) physical activity and sedentary time were objectively measured. Logistic and linear regression analyses examined cross-sectional and longitudinal associations between MVPA, VPA, organized sport, TV viewing, sedentary time, and symptoms of depression.
There were no cross-sectional or longitudinal associations between MVPA, VPA, organized sport, sedentary time, and symptoms of depression among boys or girls. However, having symptoms of depression in 2004 did predict higher TV viewing among adolescent girls in 2006 (approximately 168 minutes/week more TV viewing; P ≤ .001).
MVPA, VPA, organized sport and objectively-measured sedentary time appeared unrelated to depressive symptoms in this sample, but depressive symptoms predicted increased TV viewing over time among adolescent girls. Further research is required to determine the clinical relevance of this finding.
Eimear Keane, Xia Li, Janas M. Harrington, Anthony P. Fitzgerald, Ivan J. Perry and Patricia M. Kearney
Globally, public health policies are targeting modifiable lifestyle behaviors. We explore the independent association of moderate-to-vigorous physical activity (MVPA) and sedentary behavior on the risk of childhood overweight/obesity.
A cross-sectional survey of children aged 8–11 years (N = 826). Objective body mass index was used to classify children as normal weight or overweight/obese. Children wore wrist-worn Geneactiv accelerometers for 7-days and thresholds were applied to categorize MVPA and sedentary time. Screen time (ST) was parent reported. Poisson regression examined the independent association of (1) MVPA (2), objective sedentary time and (3) ST on the risk of overweight/obesity.
Overall, 23.7% (95% CI, 20.8–26.6%) of children were overweight/obese. On average, children spent 10.8% of waking time at MVPA and 61.3% sedentary. One-fifth (22.1%, 95% CI, 19.3–25.0%) of children achieved MVPA recommendations (≥ 60 min each day) and 17.5% (95% CI, 14.9–20.1%) met ST recommendations (<2 hr per day). Time spent at MVPA was inversely associated with the risk of overweight/obese independent of total sedentary time. Total time spent sedentary was not associated with overweight/obese independent of MVPA. ST was associated with an increased risk of overweight/obese independent of physical activity.
Few schoolchildren met physical activity and screen time recommendations suggesting population based measures are needed.