levels that are similar to older individuals in the general population ( George, Rosenkranz, & Kolt, 2013 ). On the other hand, national U.S. data show a strong relationship between longer sedentary time and presence of disability, independent of time spent performing moderate or vigorous physical
Sungchul Lee, Sangyoon Lee, Seongryu Bae, Kazuhiro Harada, Songee Jung, Keitaro Makino and Hiroyuki Shimada
Claudia Fischer, Mine Yılıdrım, Jo Salmon and Mai J.M. Chinapaw
Actigraph accelerometers are hypothesized to be valid measurements for assessing children’s sedentary time. However, there is considerable variation in accelerometer cut-points used. Therefore, we compared the most common accelerometer sedentary cut-points of children performing sedentary behaviors. Actigraph Actitrainer uniaxial accelerometers were used to measure children’s activity intensity (29 children, 5-11 years old) during different activities, namely playing computer games, nonelectronic sedentary games, watching television and playing outdoors. A structured protocol was the criterion for assessing the validity of four common cut-points (100, 300, 800, 1100 counts/minute). The median counts during all sedentary behaviors were below the lowest comparison cut-point of 100 cpm. The 75th percentile values for the sedentary behaviors were always below the cut-point of 300 cpm. Our results suggest that the cut-point of <100 cpm is the most appropriate.
Krista Schroeder, Martha Y. Kubik, Jiwoo Lee, John R. Sirard and Jayne A. Fulkerson
The greatest decline in youth activity levels occurs during adolescence, 1 – 4 suggesting that preadolescence may be a critical time for intervention. Better understanding of the individual and interpersonal factors associated with physical activity (PA) and sedentary time during preadolescence
Janelle M. Wagnild and Tessa M. Pollard
association between TV time and poor health outcomes is stronger than the association between total sitting time 1 – 3 or time spent sitting in other contexts 4 and poor health. Discussions of possible explanations for the relatively large effects of TV time compared with total sedentary time (ST) are
Scott E. Crouter, Paul R. Hibbing and Samuel R. LaMunion
+ <150 VA counts/min 38.0±32.8 22.9 84.4 23.8 121.1 GT3X+ <200 VA counts/min 40.8±34.7* ,^ 24.7 91.0 26.2 138.7 Note . VM, vector magnitude; VA, vertical axis; RMSE, root mean squared error; MAPE, mean absolute percent error. Sedentary time from activPAL and GT3X+ inclinometer based on labelling all
Eric E. Wickel
This study examined associations between sedentary time, physical activity (PA), and executive function among youth participating in the Study of Early Child Care and Youth Development.
Sedentary time and PA (light, moderate, vigorous, and moderate-to-vigorous (MVPA)) were objectively assessed at 9 and 15 years, while executive function (inhibition, working memory, and fluid intelligence) were assessed at 15 years. Regression models were used to examine associations.
Sedentary time at 9 years predicted fluid intelligence at 15 years (B = 0.031), whereas increased sedentary time from 9 to 15 years predicted higher inhibition (B = 0.003), working memory (B = 0.074), and fluid intelligence (B = 0.029). Relatively lower levels of working memory at 15 years were predicted from increased levels of light PA, moderate PA, and MVPA from 9 to 15 years (B = –0.075, –0.293, and –0.173, respectively). At 15 years, inhibition, working memory, and fluid intelligence were significantly associated with sedentary time (B = 0.003, 0.055, and 0.045, respectively).
Childhood sedentary time and PA may affect executive function at 15 years; however, prospective studies are needed to examine the concurrent change in both sedentary time and PA with executive function.
Rachel G. Walker, Joyce Obeid, Thanh Nguyen, Hilde Ploeger, Nicole A. Proudfoot, Cecily Bos, Anthony K. Chan, Linda Pedder, Robert M. Issenman, Katrin Scheinemann, Maggie J. Larché, Karen McAssey and Brian W. Timmons
The objectives of this study were to (i) assess sedentary time and prevalence of screen-based sedentary behaviors of children with a chronic disease and (ii) compare sedentary time and prevalence of screen-based sedentary behaviors to age- and sex-matched healthy controls. Sixty-five children (aged 6-18 years) with a chronic disease participated: survivors of a brain tumor, hemophilia, type 1 diabetes mellitus, juvenile idiopathic arthritis, cystic fibrosis, and Crohn’s disease. Twenty-nine of these participants were compared with age- and sex-matched healthy controls. Sedentary time was measured objectively by an ActiGraph GT1M or GT3x accelerometer worn for 7 consecutive days and defined as less than 100 counts per min. A questionnaire was used to assess screen-based sedentary behaviors. Children with a chronic disease engaged in an average of 10.2 ± 1.4 hr of sedentary time per day, which comprised 76.5 ± 7.1% of average daily monitoring time. There were no differences between children with a chronic disease and controls in sedentary time (adjusted for wear time, p = .06) or in the prevalence of TV watching, and computer or video game usage for varying durations (p = .78, p = .39 and, p = .32 respectively). Children with a chronic disease, though relatively healthy, accumulate high levels of sedentary time, similar to those of their healthy peers.
Lucy Kate Lewis, Carol Maher, Kevin Belanger, Mark Tremblay, Jean-Philippe Chaput and Tim Olds
This study investigated associations between weather conditions, physical activity, and sedentary time in primary school-aged children in Australia and Canada.
Cross-sectional data on 9–11-year-old children from the Australian (n = 491) and Canadian (n = 524) sites of the International Study of Childhood Obesity, Lifestyle and the Environment were used. Minutes of daily moderate-to-vigorous-physical-activity (MVPA) and sedentary time were determined from 7-day, 24-h accelerometry (Actigraph GT3X+ triaxial accelerometer). Day-matched weather data (temperature, rainfall, snowfall, relative humidity, wind speed) were obtained from the closest weather station to participants’ schools. Covariates included parental highest education level, day type, sex, and BMI z-scores. Generalized mixed model analyses allowing for clustering of participants within schools were completed. Scatterplots with Loess curves were created for maximum temperature, MVPA, and sedentary time.
Daily maximum temperature was significantly associated with MVPA and sedentary time in Australia (MVPA p = .05, sedentary p = .01) and Canada (p < .001, p = .001). Rainfall was negatively associated with MVPA in Australia (p < .001) and positively associated with sedentary time in Canada (p = .02).
MVPA and sedentary time appear to be optimal when the maximum temperature ranges between 20°C and 25°C in both countries. The findings have implications for study design and interpretation for surveillance and intervention studies.
Claudio Sartini, Richard W Morris, Peter H Whincup, S Goya Wannamethee, Sarah Ash, Lucy Lennon and Barbara J Jefferis
Sedentary behavior is very common in older adults and a risk factor for mortality. Understanding determinants of sedentary behavior may help in defining strategies aimed to reduce the time spent sedentary. The degree of difference in sedentary time attributable to varying temperatures has not been yet estimated in older men.
Men aged 71 to 91 years participating in an established UK population-based cohort study were invited to wear an Actigraph GT3X accelerometer for 1 week in 2010–12. Outcome was sedentary time (<1.5 Metabolic Equivalent of Task) in minutes per day. Associations between daily outdoor maximum temperature and accelerometer-measured sedentary time were estimated using multilevel models.
43% (1361/3137) of invited men participated in the study and provided adequate data. Men spent on average 615 minutes in sedentary time per day (72% of the total accelerometer-wear time). After adjusting for covariates, men spent 26 minutes more per day (P < .001) in sedentary time when temperatures were in the lowest (–3.5; 9.2°C) versus highest quintile (19.1; 29.5°C).
Sedentary time in older adults is highest at lowest temperatures, typically recorded in winter. Findings are relevant for guidelines: interventions may consider targeting older men in winter providing recommendations for minimizing sedentariness on daily basis.
Ane Kristiansen Solbraa, Ulf Ekelund, Ingar M. Holme, Sidsel Graff-Iversen, Jostein Steene-Johannessen, Eivind Aadland and Sigmund Alfred Anderssen
Sex, age, body mass index (BMI), perceived health and health behavior are correlates known to affect physical activity and sedentary time. However, studies have often been cross-sectional, and less is known about long-term correlates. Thus, the aims were to investigate 1) the associations between a set of characteristics (demographic, biological, psychological, and behavioral) and objectively measured physical activity and sedentary time at 13-year follow-up, and 2) the association between changes in these characteristics over time and physical activity and sedentary time.
Baseline characteristics were collected in 40-year-olds in 1996, and follow-up data on objectively measured physical activity and sedentary time were obtained in 2009 (n = 240). Data were analyzed by multiple linear regressions.
Self-reported physical activity (P < .001) and improved perceived health (P = .046) were positively associated with moderate-to-vigorous physical activity (MVPA) whereas BMI (P = .034) and increased BMI (P = .014) were negatively associated with MVPA at follow-up. Women spent less time being sedentary than men (P = .019). Education (P < .001) was positively associated and improved perceived health (P = .010) was negatively associated with sedentary time at follow-up.
MVPA and sedentary time at follow-up were associated with behavioral, biological and demographic correlates. However, the nature of our analyses prevents us from inferring causality.