the iPad present [20.9 (12.4) min] than without the iPad present [13.6 (13.2) min]. Figure 2 —Sedentary time for each condition [mean ( SEM )]. *The level of significance was set a priori at P ≤ .05. Condition with the iPad was significantly greater than the condition without the iPad. Liking
Mallory S. Kobak, Andrew Lepp, Michael J. Rebold, Hannah Faulkner, Shannon Martin and Jacob E. Barkley
Heather K. Neilson, Ruth Ullman, Paula J. Robson, Christine M. Friedenreich and Ilona Csizmadi
The qualitative attributes and quantitative measurement properties of physical activity questionnaires are equally important considerations in questionnaire appraisal, yet fundamental aspects such as question comprehension are not often described in the literature. Here we describe the use of cognitive interviewing to evaluate the Sedentary Time and Activity Reporting Questionnaire (STAR-Q), a self-administered questionnaire designed to assess overall activity energy expenditure and sedentary behavior.
Several rounds of one-on-one interviews were conducted by an interviewer trained in qualitative research methods. Interviewees included a convenience sample of volunteers and participants in the Tomorrow Project, a large cohort study in Alberta, Canada. Following each round of interviews the STAR-Q was revised and cognitively tested until saturation was achieved.
Six rounds of cognitive interviewing in 22 adults (5 males, 17 females) age 23−74 years, led to revisions involving 1) use of recall aids; 2) ambiguous terms; and 3) specific tasks, such as averaging across multiple routines, reporting time asleep and self-care, and reporting by activity domain.
Cognitive interviewing is a critical step in questionnaire development. Knowledge gained in this study led to revisions that improved respondent acceptability and comprehension of the STAR-Q and will complement ongoing validity testing.
Eero A. Haapala, Juuso Väistö, Aapo Veijalainen, Niina Lintu, Petri Wiklund, Kate Westgate, Ulf Ekelund, Virpi Lindi, Soren Brage and Timo A. Lakka
To investigate the relationships of objectively measured physical activity (PA) and sedentary time (ST) to arterial stiffness in prepubertal children.
Altogether 136 children (57 boys, 79 girls) aged 6–8-years participated in the study. Stiffness index (SI) was assessed by pulse contour analysis based on photoplethysmography. ST, light PA, moderate PA, and vigorous PA were assessed using combined acceleration and heart rate monitoring. We investigated the associations of ST (<1.5METs) and time spent in intensity level of PA above 2–7METs in min/d with SI using linear regression analysis. We studied the optimal duration and intensity of PA to identify children being in the highest quarter of SI using Receiver Operating Characteristics curves.
Moderate PA, vigorous PA, and cumulative time spent in PA above 3 (β=–0.279, p = .002), 4 (β =–0.341, P<0.001), 5 (β =–0.349, P<0.001), 6 (β =–0.312, P<0.001), and 7 (β =–0.254, p = .005) METs were inversely associated with SI after adjustment for age, sex, and monitor wear time. The cutoffs for identifying children being in the highest quarter of SI <68 min/d for PA exceeding 5 METs and <26 min/d for PA exceeding 6 METs.
Lower levels of PA exceeding 3–6 METs were related to higher arterial stiffness in children.
Emily L. Mailey, Neha P. Gothe, Thomas R. Wójcicki, Amanda N. Szabo, Erin A. Olson, Sean P. Mullen, Jason T. Fanning, Robert W. Motl and Edward McAuley
The criteria one uses to reduce accelerometer data can profoundly influence the interpretation of research outcomes. The purpose of this study was to examine the influence of 3 different interruption periods (i.e., 20, 30, and 60 min) on the amount of data retained for analyses and estimates of sedentary time among older adults. Older adults (N = 311, M age = 71.1) wore an accelerometer for 7 d and reported wear time on an accelerometer log. Accelerometer data were downloaded and scored using 20-, 30-, and 60-min interruption periods. Estimates of wear time, derived using each interruption period, were compared with self-reported wear time, and descriptive statistics were used to compare estimates of sedentary time. Results showed a longer interruption period (i.e., 60 min) yields the largest sample size and the closest approximation of self-reported wear time. A short interruption period (i.e., 20 min) is likely to underestimate sedentary time among older adults.
Brooke J. Cull, Mark. D. Haub, Richard R. Rosenkranz, Thomas Lawler and Sara K. Rosenkranz
Sedentary time is an independent risk factor for chronic diseases and mortality. It is unknown whether active adults alter their dietary and/or physical activity behaviors in response to imposed sedentary time, possibly modifying risk. The aim of this study was to determine whether imposed sedentary time would alter typical behaviors of active adults.
Sixteen physically active, young adults were randomized to the no-intervention control (CON, n = 8) group or the sedentary-intervention (SIT, n = 8) group. SIT participants attended monitored sedentary sessions (8 wk, 10 h/wk). Assessments including diet and physical activity occurred at baseline, week 4, and week 9.
There were no differences (P > .05) between CON and SIT groups for step counts or time spent in sedentary, light, moderate, or vigorous physical activity when comparing a week during imposed sedentary time (week 4) to baseline and week 9. At week 4, caloric intake was not different from baseline (P > .05) in either group. Caloric intake decreased significantly (P > .05) in SIT from baseline to week 9.
Active adults did not alter physical activity or dietary behaviors during the imposed sedentary intervention. However, SIT reduced caloric intake from baseline to week 9, indicating a possible compensatory response to imposed sitting in active adults.
Christine A. Pellegrini, Jing Song, Rowland W. Chang, Pamela A. Semanik, Jungwha Lee, Linda Ehrlich-Jones, Daniel Pinto and Dorothy D. Dunlop
We examined if changes in moderate-to-vigorous physical activity (MVPA), light activity, and sedentary behavior are related to weight change over a 2-year period in obese adults with/elevated risk for knee osteoarthritis.
Weight, physical activity, and sedentary time at baseline and 2 years were obtained from 459 obese participants from the Osteoarthritis Initiative. Weight change was categorized as ≥ 10 lbs, 5.0 to 9.9 lbs, 4.9 to –4.9 lbs, –5.0 to –9.9 lbs, and ≤ –10 lbs. We examined the association between 2-year weight change categories and changes in activity/sedentary time from accelerometer monitoring by multiple linear regression adjusted for baseline weight, demographic, and health factors.
Across the 5 weight categories (loss to gain), average 2-year change ranged from -7.4 to 28.0 sedentary minutes/day, 4.2 to –23.1 light activity minutes/day, and 3.2 to –4.9 MVPA minutes/day, respectively. Higher weight loss categories were separately associated with increased MVPA (P for trend < 0.001) and less sedentary gain (P for trend = 0.01). Weight loss categories had a strong trend with light activity gain but not statistically significant (P for trend = 0.06).
Small increases in MVPA and decreases in sedentary time over 2 years were associated with weight loss among adults with obesity and with or at elevated risk for knee osteoarthritis.
Robert M. Ojiambo, Chris Easton, Jose A. Casajús, Kenn Konstabel, John J. Reilly and Yannis Pitsiladis
Urbanization affects lifestyles in the developing world but no studies have assessed the impact on objectively measured physical activity in children and adolescents from sub-Saharan Africa.
To compare objectively measured habitual physical activity, sedentary time, and indices of adiposity in adolescents from rural and urban areas of Kenya.
Physical activity and sedentary time were assessed by accelerometry for 5 consecutive days in 97 (50 female and 47 male) rural and 103 (52 female and 51 male) urban adolescents (mean age 13 ± 1 years). Body Mass Index (BMI) and BMI z-scores were used to assess adiposity.
Rural males spent more time in moderate-to-vigorous intensity physical activity (MVPA) compared with urban males (68 ± 22 vs. 50 ± 17 min, respectively; P < .001). Similarly, Rural females spent more time in MVPA compared with urban females (62 ± 20 vs. 37 ± 20 min, respectively; P < .001). Furthermore, there were significant differences in daily sedentary time between rural and urban subjects. Residence (rural vs. urban) significantly (P < .001) influenced BMI z-score (R 2 = .46).
Rural Kenyan adolescents are significantly more physically active (and less sedentary) and have lower indices of adiposity compared with urban adolescents and this is a likely refection of the impact of urbanization on lifestyle in Kenya.
Heidi J. Syväoja, Anna Kankaanpää, Jouni Kallio, Harto Hakonen, Janne Kulmala, Charles H. Hillman, Anu-Katriina Pesonen and Tuija H. Tammelin
raised concerns about the effects of a physically inactive lifestyle on children’s health during maturation and across the lifespan, as physical activity (PA) continues to decrease and sedentary time (ST) continues to increase from childhood to adolescence and adulthood. 5 , 6 The association of a
Rodrigo Antunes Lima, Karin A. Pfeiffer, Niels Christian Møller, Lars Bo Andersen and Anna Bugge
girls and better academic performance in boys. Therefore, more work is necessary to examine relationships between PA and academic performance across time. In addition, only a few studies have evaluated the relation between sedentary time (SED) and academic performance, 7 – 11 and to our knowledge, only
Natasha Reid, Justin W. Keogh, Paul Swinton, Paul A. Gardiner and Timothy R. Henwood
, & Luiz, 2014 ). Furthermore, previous studies have indicated that there is a link between sedentary time and all-cause mortality ( Biddle et al., 2016 ) with the risk increased by 34% among those who sit for 10 hr or more per day ( Chau et al., 2013 ). However, the majority of studies examining the