Pedro Hallal and Ulf Ekelund
Justin B. Moore, Michael W. Beets, Sara F. Morris and Mary Bea Kolbe
Most youth fail to achieve 60 minutes of moderate-to-vigorous physical activity (MVPA) daily while engaging in excessive amounts of sedentary behaviors. The objective of this investigation was to identify modifiable factors associated with meeting MVPA recommendations or engaging in greater than 55% of observed time sedentary.
Youth (N = 1005, 10.5 yrs, 52% girls) wore accelerometers with daily minutes of MVPA (≥ 2296 counts·min−1) classified as ≥ 60mins/d vs. < 60min/d of MVPA. Sedentary behavior (< 100 counts·min−1) was classified as < 55% or ≥ 55% of total wear-time. Two-level random effects logit survival models for repeated events (days of monitoring) examined the association of psychosocial self-report measures and demographic characteristics to meeting the MVPA recommendation and spending ≥ 55% of time sedentary.
Wednesdays, Thursdays, and Sundays were associated with a decreased likelihood of meeting MVPA recommendations relative to Mondays. Wednesday thru Sunday were associated with a decreased likelihood of spending ≥ 55% of time sedentary. Being a boy, receiving transportation, and fewer reported barriers to physical activity were associated with meeting MVPA recommendations.
Relatively few youth are engaging in recommended levels of physical activity. Provision of transportation and reduction of barriers to physical activity are relevant targets for physical activity promotion.
Katya M. Herman, Gilles Paradis, Marie-Eve Mathieu, Jennifer O’Loughlin, Angelo Tremblay and Marie Lambert
This study examines the association between objectively-measured physical activity (PA) intensities and sedentary behavior (SED) in a cohort of 532 children aged 8–10 y. PA and SED were assessed by accelerometer over 7-days. Television and computer/video-game use were self-reported. Associations between PA intensities and SED variables were assessed by Spearman correlations and adjusted multiple linear regression. Higher mean daily moderate-to-vigorous and vigorous PA (MVPA, VPA) were negatively associated with mean daily SED (r = −0.47 and −0.37; p < .001), and positively associated with mean daily total PA (r = .58 and 0.46; p < .001). MVPA was also positively associated with light PA (LPA; r = .26, p < .00l). MVPA and VPA were not significantly associated with TV, computer/video or total screen time; accelerometer SED was only weakly associated with specific SED behaviors. On average, for each additional 10 min daily MVPA, children accumulated >14 min less SED, and for each additional 5 min VPA, 11 min less SED. Thus, over the course of a week, higher mean daily MVPA may displace SED time and is associated with higher total PA over and above the additional MVPA, due to concomitant higher levels of LPA. Public health strategies should target both MVPA and SED to improve overall PA and health in children.
Ing-Mari Dohrn, Maria Hagströmer, Mai-Lis Hellénius and Agneta Ståhle
To describe objectively-measured physical activity levels and patterns among community-dwelling older adults with osteoporosis, impaired balance, and fear of falling, and to explore the associations with gait, balance performance, falls self-efficacy, and health-related quality of life (HRQoL).
Ninety-four individuals (75.6 ± 5.4 years) were included. Physical activity was assessed with pedometers and accelerometers. Mean steps/day, dichotomized into < 5,000 or = 5,000 steps/day, and time spent in different physical activity intensities were analyzed. Gait was assessed with a GAITRite walkway, balance performance was assessed with the modified figure-eight test and oneleg stance, falls self-efficacy was assessed with the Falls Efficacy Scale International, and HRQoL was assessed with Short Form-36.
Mean steps/day were 6,201 (991–17,156) and 40% reported < 5,000 steps/day. Participants with < 5,000 steps/day spent more time sedentary, had slower gait speed, poorer balance performance, and lower HRQoL than participants with ≥ 5,000 steps/day. No participants with < 5,000 met the recommended level of physical activity.
Sarah Kozey Keadle, Shirley Bluethmann, Charles E. Matthews, Barry I. Graubard and Frank M. Perna
This paper tested whether a physical activity index (PAI) that integrates PA-related behaviors (ie, moderate-to-vigorous physical activity [MVPA] and TV viewing) and performance measures (ie, cardiorespiratory fitness and muscle strength) improves prediction of health status.
Participants were a nationally representative sample of US adults from 2011 to 2012 NHANES. Dependent variables (self-reported health status, multimorbidity, functional limitations, and metabolic syndrome) were dichotomized. Wald-F tests tested whether the model with all PAI components had statistically significantly higher area under the curve (AUC) values than the models with behavior or performance scores alone, adjusting for covariates and complex survey design.
The AUC (95% CI) for PAI in relation to health status was 0.72 (0.68, 0.76), and PAI-AUC for multimorbidity was 0.72 (0.69, 0.75), which were significantly higher than the behavior or performance scores alone. For functional limitations, the PAI AUC was 0.71 (0.67, 0.74), significantly higher than performance, but not behavior scores, while the PAI AUC for metabolic syndrome was 0.69 (0.66, 0.73), higher than behavior but not performance scores.
These results provide empirical support that an integrated PAI may improve prediction of health and disease. Future research should examine the clinical utility of a PAI and verify these findings in prospective studies.
Nirjhar Dutta and Mark A. Pereira
The objective of this study was to estimate the mean difference in energy expenditure (EE) in healthy adults between playing active video games (AVGs) compared with traditional video games (TVGs) or rest.
A systematic search was conducted on Ovid MEDLINE, Web of Knowledge, and Academic Search Premier between 1998 and April 2012 for relevant keywords, yielding 15 studies. EE and heart rate (HR) data were extracted, and random effects meta-analysis was performed.
EE during AVG play was 1.81 (95% CI, 1.29–2.34; I 2 = 94.2%) kcal/kg/hr higher, or about 108 kcal higher per hour for a 60-kg person, compared with TVG play. Mean HR was 21 (95% CI, 13.7–28.3; I 2 = 93.4%) beats higher per minute during AVG play compared with TVG play. There was wide variation in the EE and HR estimates across studies because different games were evaluated. Overall metabolic equivalent associated with AVG play was 2.62 (95% CI, 2.25–3.00; I 2 = 99.2%), equivalent to a light activity level. Most studies had low risk of bias due to proper study design and use of indirect calorimetry to measure EE.
AVGs may be used to replace sedentary screen time (eg, television watching or TVG play) with light activity in healthy adults.
Jennifer L. Copeland and Dale W. Esliger
Despite widespread use of accelerometers to objectively monitor physical activity among adults and youth, little attention has been given to older populations. The purpose of this study was to define an accelerometer-count cut point for a group of older adults and to then assess the group’s physical activity for 7 days. Participants (N = 38, age 69.7 ± 3.5 yr) completed a laboratory-based calibration with an Actigraph 7164 accelerometer. The cut point defining moderate to vigorous physical activity (MVPA) was 1,041 counts/min. On average, participants obtained 68 min of MVPA per day, although more than 65% of this occurred as sporadic activity. Longer bouts of activity occurred in the morning (6 a.m. to 12 p.m.) more frequently than other times of the day. Almost 14 hr/day were spent in light-intensity activity. This study demonstrates the rich information that accelerometers provide about older adult activity patterns—information that might further our understanding of the relationship between physical activity and healthy aging.
Molly P. O’Sullivan, Matthew R. Nagy, Shannon S. Block, Trevor R. Tooley, Leah E. Robinson, Natalie Colabianchi and Rebecca E. Hasson
Purpose: The purpose of this study was to compare the effects of intermittent activity performed at varying intensities and of prolonged sitting on physical activity compensation. Methods: A total of 33 children (14 boys and 19 girls; age 7–11 y; 24% overweight/obese; 61% nonwhite) completed 4 experimental conditions in random order: 8 hours of sitting interrupted with 20 two-minute low-, moderate-, or high-intensity activity breaks or 20 two-minute sedentary computer game breaks. Physical activity energy expenditure (PAEE) was assessed via accelerometry to establish baseline PAEE and throughout each condition day (8-h in-lab PAEE, out-of-lab PAEE, and 3-d postcondition). Results: Compared with baseline PAEE, total daily PAEE was significantly higher during the high-intensity condition day (153 ± 43 kcal, P = .03), unchanged during the low-intensity (−40 ± 23 kcal, P > .05) and moderate-intensity condition days (−11 ± 18 kcal, P > .05), and decreased in response to prolonged sitting (−79 ± 22 kcal, P = .03). There were no significant differences in PAEE 3-day postcondition across conditions (P > .05). Conclusion: Despite the varying levels of PAEE accumulated during the 8-hour laboratory conditions, out-of-lab PAEE during each condition day and 3-day postcondition did not change from the baseline. These findings provide preliminary evidence that spontaneous physical activity in children does not change in response to intermittent activity or prolonged sitting.
Lennart Raudsepp and Eva-Maria Riso
The objective of this study was to examine the prospective relationship and changes in sedentary behavior between adolescent girls, their mothers and best friends over time.
The results are based on 122 girls aged 11–12 years at baseline measurement, their mothers and best friends who completed ecological momentary assessment diary for the assessment of sedentary behavior. All measurements were taken at 3 time points separated by one year. We used structural equation modeling to examine associations among sedentary behavior of adolescent girls, their mothers and best friends.
A linear growth model for adolescent girls’ and their best friends’ sedentary behavior fit the data well, revealing an overall significant increase in sedentary behavior across time. Initial levels of mothers’ and best friends’ sedentary behavior were positively related with sedentary behavior of adolescent girls. The changes of adolescent girls’ and best friends’ sedentary behavior across 3 years were positively related. Cross-lagged panel analysis demonstrated significant reciprocal effects between adolescent girls’ and best friends’ sedentary behavior. Mothers’ sedentary behavior at baseline predicted daughters’ sedentary behavior at 1-year follow-up and vice versa.
From early to midadolescence, changes in adolescent girls’ sedentary behavior were associated with changes in best friends’ sedentary behavior. These findings suggest reciprocal associations between sedentary behavior of adolescent girls and their best friends.
Kelly R. Laurson, Joey A. Lee and Joey C. Eisenmann
Physical activity (PA), television time (TV), and sleep duration (SLP) are considered individual risk factors for adolescent obesity. Our aim was to investigate the concurrent influence of meeting PA, SLP, and TV recommendations on adolescent obesity utilizing 2011 Youth Risk Behavior Surveillance Survey (YRBSS) data.
Subjects included 9589 (4874 females) high school students. PA, SLP, and TV were categorized utilizing established national recommendations and youth were cross-tabulated into 1 of 8 groups based on meeting or not meeting each recommendation. Logistic models were used to examine the odds of obesity for each group. Results: Youth meeting the PA recommendation were not at increased odds of obesity, regardless of SLP or TV status. However, not meeting any single recommendation, in general, led to increased odds of not meeting the other two. In boys, 11.8% met all recommendations while 14.1% met 0 recommendations. In girls, only 5.0% met all recommendations while 17.8% met none.
Boys and girls not meeting any of the recommendations were 4.0 and 3.8 times more likely to be obese compared with their respective referent groups. Further research considering the simultaneous influence these risk factors may have on obesity and on one another is warranted.