Validity of a self-report recall tool for estimating sedentary behaviour in adults

BACKGROUND Sedentary behavior is continuing to emerge as an important target for health promotion. The purpose of this study was to determine the validity of a self-report use of time recall tool, the Multimedia Activity Recall for Children and Adults (MARCA) in estimating time spent sitting/lying, compared with a device-based measure. METHODS Fifty-eight participants (48% female, [mean±standard deviation] 28±7.4 years of age, 23.9±3.05 kg/m2) wore an activPAL device for 24-h and the following day completed the MARCA. Pearson correlation coefficients (r) were used to analyse convergent validity of the adult MARCA compared with activPAL estimates of total sitting/lying time. Agreement was examined using Bland-Altman plots. RESULTS According to activPAL estimates, participants spent 10.4 hr/day [standard deviation (SD)=2.06] sitting or lying down while awake. The correlation between MARCA and activPAL estimates of total sit/lie time was r=0.77 (95% confidence interval = 0.64-0.86; p<0.001). Bland-Altman analyses revealed a mean bias of +0.59 hr/day with moderately wide limits of agreement (-2.35 hours to +3.53 hr/day). CONCLUSIONS This study found a moderate to strong agreement between the adult MARCA and the activPAL, suggesting that the MARCA is an appropriate tool for the measurement of time spent sitting or lying down in an adult population.

Intentions Toward Physical Activity and Resting Behavior in Pregnant Women: Using the Theory of Planned Behavior Framework in a Cross-Sectional Study

BACKGROUND: Pregnant women are recommended to 1) perform daily moderate-intensity physical activity and 2) limit the amount of sedentary time. Many women do not meet these recommendations. Reduced physical activity and increased sedentary behavior may result from women actively intending to rest during pregnancy. The Theory of Planned Behavior (TPB) has been used to assess attitudes (e.g., positive/negative beliefs), subjective norms (e.g., perception of others' views), perceived behavioral control (PBC) (e.g., self-efficacy), and intention toward exercising while pregnant but has not been applied to aspects pertaining to resting during pregnancy.

METHODS: Pregnant women (n = 345) completed a cross-sectional questionnaire that included two TPB Questionnaires where the target behaviors were 1) being physically active and 2) resting. Bootstrapped paired t tests, ANOVA, and linear hierarchal regression analyses were performed to identify predictors of intentions and whether intentions toward the two behaviors varied at different stages of pregnancy.

RESULTS: As women progressed in their pregnancy, their attitude, PBC, and intention toward being physically active all significantly declined. A positive attitude, subjective norms, and intention toward resting all significantly increased with the advancing trimester. Self-reported health conditions predicted lower intention for physical activity but not for resting.

DISCUSSION: The significantly inverse relationship between physical activity and resting across time suggests that women feel they should focus on one behavior at the expense of the other. Finding that women generally do not perceive these behaviors as mutually compatible has implications in strategizing as to how to encourage women to be active during pregnancy.

Too little exercise and too much sitting : inactivity physiology and the need for new recommendations on sedentary behaviour

Moderate-to vigorous-intensity physical activity has an established preventive role in cardiovascular disease, type 2 diabetes, obesity, and some cancers. However, recent epidemiologic evidence suggests that sitting time has deleterious cardiovascular and metabolic effects that are independent of whether adults meet physical activity guidelines. Evidence from “inactivity physiology” laboratory studies has identified unique mechanisms that are distinct from the biologic bases of exercising. Opportunities for sedentary behaviors are ubiquitous and are likely to increase with further innovations in technologies. We present a compelling selection of emerging evidence on the deleterious effects of sedentary behavior, as it is underpinned by the unique physiology of inactivity. It is time to consider excessive sitting a serious health hazard, with the potential for ultimately giving consideration to the inclusion of too much sitting (or too few breaks from sitting) in physical activity and health guidelines.

Agreement between activPAL and ActiGraph for assessing children's sedentary time

Background
Accelerometers have been used to determine the amount of time that children spend sedentary. However, as time spent sitting may be detrimental to health, research is needed to examine whether accelerometer sedentary cut-points reflect the amount of time children spend sitting. The aim of this study was to: a) examine agreement between ActiGraph (AG) cut-points for sedentary time and objectively-assessed periods of free-living sitting and sitting plus standing time using the activPAL (aP); and b) identify cut-points to determine time spent sitting and sitting plus standing.

Methods
Forty-eight children (54% boys) aged 8–12 years wore a waist-mounted AG and thigh-mounted aP for two consecutive school days (9–3:30 pm). AG data were analyzed using 17 cut-points between 50–850 counts·min−1 in 50 counts·min−1 increments to determine sedentary time during class-time, break time and school hours. Sitting and sitting plus standing time were obtained from the aP for these periods. Limits of agreement were computed to evaluate bias between AG50 to AG850 sedentary time and sitting and sitting plus standing time. Receiver Operator Characteristic (ROC) analyses identified AG cutpoints that maximized sensitivity and specificity for sitting and sitting plus standing time.

Results
The smallest mean bias between aP sitting time and AG sedentary time was AG150 for class time (3.8 minutes), AG50 for break time (−0.8 minutes), and AG100 for school hours (−5.2 minutes). For sitting plus standing time, the smallest bias was observed for AG850. ROC analyses revealed an optimal cut-point of 96 counts·min−1 (AUC = 0.75) for sitting time, which had acceptable sensitivity (71.7%) and specificity (67.8%). No optimal cut-point was obtained for sitting plus standing (AUC = 0.51).

Conclusions
Estimates of free-living sitting time in children during school hours can be obtained using an AG cut-point of 100 counts·min−1. Higher sedentary cut-points may capture both sitting and standing time.

Patterns of physical activity and sedentary behaviour in preschool children

Background
Little is known about patterns of sedentary behavior (SB) and physical activity among preschoolers. Therefore, in this observational study patterns of SB and moderate-to-vigorous physical activity (MVPA) were examined in detail throughout the week in preschool-aged boys and girls.

Methods
A sample of 703 Melbourne preschool children (387 boys; 4.6 ± 0.7 y) were included in data analysis. SB and MVPA data were collected using accelerometry over an eight-day period. Percentage of time per hour in SB and in MVPA between 08:00 h and 20:00 h was calculated. Multi-level logistic regression models were created to examine the hour-by-hour variability in SB and MVPA for boys and girls across weekdays and weekend days. Odds ratios (OR) were calculated to interpret differences in hour-by-hour SB and MVPA levels between boys and girls, and between weekdays and weekend days.

Results
The highest SB levels co-occurred with the lowest MVPA levels from the morning till the early afternoon on weekdays, and during the morning and around midday on weekends. Besides, participation in SB was the lowest and participation in MVPA was the highest from the mid afternoon till the evening on weekdays and weekend days. The variability across the hours in SB and, especially, in MVPA was rather small throughout weekdays and weekends. These patterns were found in both boys and girls. During some hours, girls were found to be more likely than boys to demonstrate higher SB levels (OR from 1.08 to 1.16; all p < 0.05) and lower MVPA levels (OR from 0.75 to 0.88; all p < 0.05), but differences were small. During weekends, hour-by-hour SB levels were more likely to be lower (OR from 0.74 to 0.98; all p < 0.05) and hour-by-hour MVPA levels were more likely to be higher (OR from 1.15 to 1.50; all p < 0.05), than during weekdays, in boys and girls.

Conclusion
Entire weekdays, especially from the morning till the early afternoon, and entire weekend days are opportunities to reduce SB and to promote MVPA in preschool-aged boys and girls. Particularly weekdays hold the greatest promise for improving SB and MVPA. No particular time of the week was found where one sex should be targeted.

Differences between 9-11 year old British Pakistani and White British girls in physical activity and behavior during school recess

Background School recess provides an important opportunity for children to engage in physical activity. Previous studies indicate that children and adults of South Asian origin are less active than other ethnic groups in the United Kingdom, but have not investigated whether activity differs within the shared school environment. The aim of this study was to test the hypothesis that British Pakistani girls aged 9–11 years are less active during recess than White British girls.

Methods In Study One, the proportion of recess spent by 137 White British (N = 70) and British Pakistani (N = 67) girls in sedentary behavior, moderate-to-vigorous activity (MVPA) and vigorous activity (VPA) was determined using accelerometry. In Study Two, 86 White British (N = 48) and British Pakistani (N = 38) girls were observed on the playground using the System for Observing Children’s Activity and Relationships during Play (SOCARP). Accelerometry data were collected during observations to allow identification of activities contributing to objectively measured physical activity.

Results Accelerometry data indicated that British Pakistani girls spent 2.2% (95% CI: 0.2, 4.3) less of their total recess time in MVPA and 1.3% (95% CI: 0.2, 2.4) less in VPA than White British girls. Direct observation showed that British Pakistani girls spent 12.0% (95% CI: 2.9, 21.1) less playground time being very active, and 12.3% (95% CI: 1.7, 23.0) less time playing games. Time spent being very active according to direct observation data correlated significantly with accelerometer-assessed time spent in MVPA and VPA, and time spent playing games correlated significantly with accelerometer-assessed time spent in VPA, suggesting that differences in behavior observed in Study Two may have contributed to the differences in time spent in MVPA and VPA in Study One.

Conclusions British Pakistani girls were less active than White British girls during school recess. Recess has been identified as a potentially important target for the delivery of physical activity interventions; such interventions should consider ways in which the activity levels of British Pakistani girls could be increased.

Do sedentary behaviors mediate associations between socio-demographic characteristics and BMI in women living in socio-economically disadvantaged neighborhoods?

Women living in deprived neighborhoods are a risk group for overweight and obesity, particularly during the childbearing years. Several socio-demographic characteristics may compound this risk, but little is known about why this might be the case. Sedentary behaviors are emerging as a socio-demographically patterned risk factor for obesity. The purpose of the present study was to assess socio-demographic differences in sedentary behaviors, and to examine whether these behaviors could explain the relation between socio-demographic variables and BMI (BMI) in this risk group.

Neighborhood environmental attributes and adults' sedentary behaviors: review and research agenda

OBJECTIVE: Physical activity recommendations are beginning to address sedentary behaviors - time spent sitting. Environmental and policy initiatives for physical activity might assist in addressing sedentary behaviors, but sedentary-specific innovations may be required. This review synthesizes current evidence on associations of neighborhood environmental attributes with adults' sedentary behaviors. METHODS: A search was conducted using three electronic databases (PubMed, Web of Science, and Transport Research Information Services). Relevant articles were assessed for their eligibility for inclusion (English-language articles with a quantitative examination of associations of neighborhood environmental attributes with adults' sedentary behaviors). RESULTS: Within 17 studies meeting inclusion criteria, associations of environmental attributes with sedentary behaviors were examined in 89 instances. Significant associations were found in 28% (n=25) of them; however, non-significant associations were found in 56% (n=50) of these instances. The most consistent association was for lower levels of sedentary behavior among residents of urban compared to regional areas. CONCLUSIONS: There is a modest but mixed initial evidence in associations of neighborhood environmental attributes with adults' sedentary behaviors. A research agenda required for this emerging field should include the development of more relevant conceptual models, measuring domain-specific sedentary behavior objectively, examining environments in close vicinity of and a larger area around home, and the use of prospective designs.

Relationship between the objectively-assessed neighborhood area and activity behavior in Swiss youth

Background Neighborhood attributes are modifiable determinants of physical activity (PA) and sedentary behavior (SB). We tested whether the objectively-assessed built and social environment was associated with PA and SB in Swiss youth and whether sex, age and the socioeconomic position (Swiss-SEP) modified such associations. Methods We combined data of 1742 youth (ages 4 to 17) from seven studies conducted within Switzerland between 2005–2010. All youth provided accelerometer data and a home address, which was linked to objective environmental data and the Swiss-SEP-index. Associations between neighborhood attributes and PA were analyzed by multivariable multilevel regression analyses. Results The extent of green areas and building density was positively associated with PA in the total sample (p < 0.05). Factors representing centrally located areas, and more schoolchildren living nearby tended to increase PA in secondary schoolchildren, boys and those from lower-ranked socioeconomic areas. In primary schoolchildren, the extent of green areas was positively associated with PA (p = 0.05). Associations between neighborhood attributes and PA were more pronounced in youth from low socioeconomic areas. Conclusions The results indicate that some associations between neighborhood attributes and PA differ by age, sex and socioeconomic area. This should be taken into account when planning interventions to increase childhood PA.

Regional Disparities in Sedentary Behaviors and Meal Frequency in Iranian Adolescents: The CASPIAN-III Study

Background: The prevalence of obesity is increasing among Iranian youngsters like other developing countries. Objectives: This study was conducted to assess regional disparities in sedentary behaviors and meal frequency in Iranian adolescents. Patients and Methods: In this national survey, 5682 students aged 10 - 18 years from urban and rural districts of 27 provinces of Iran were selected via stratified multi-stage sampling method. The country was classified into four sub-national regions, based on criteria of the combination of geography and socioeconomic status (SES). Mean of meal frequency and physical activity levels as well as prevalence of omitting meals and sedentary behavior were compared across regions with different SES after stratifying with sex and age group. Results: Meal frequency in lower socio-economic regions was significantly higher than two other regions in 10 - 13 and 10 - 18 years old groups (P trend < 0.001). However, the mean of working hours with computer was linearly increased with increasing the SES in studied regions (P trend < 0.001), whereas the corresponding figure was not significant for the mean of watching TV (P trend > 0.05). Frequency of adolescents omitting their meals was higher in higher SES regions especially in West Iran (P < 0.001) in 10 - 13 years old age group. Having personal computer and working with it more than two hours per day mainly was observed in central Iran which ranked as the highest SES group. Conclusions: Efforts to ensure Iranian youth meet healthy food habits and screen time guidelines include limiting access to screen technologies and encouraging parents to monitor their own screen time is required.

Transtheoretical model for behavior changes: an important tool when adopting active life

Despite the worship of beauty that has ruled this globalized society and the importance of physical activity for the prevention of cardio-degenerative diseases (US.DHHS, 1996), sedentary behavior continues to increase in the population.  What strategies can be used by professionals of human movement to make the population physically active? It is at this point where the Transtheoretical Model appears as an innovative option that greatly surpasses the classic short-term biological interventions, which have focused on momentary changes produced by physiological values.  This model has great potential since it offers the theoretical basis that makes the acquisition of an active behavior possible.  This article explains the theoretical basis of the transtheoretical model, including the way to assess the stages of change and to develop different strategies to make the person active by using behavioral processes and processes of change.

The non-advertising effects of screen-based sedentary activities on acute eating behaviours in children, adolescents, and young adults. A systematic review.

Sedentary screen time may be an important determinant of childhood obesity. A number of potential mechanisms to explain the link between screen time and increased bodyweight have been proposed; however, the relationship appears to be best explained by the effects on dietary intake, which is attributed to either food advertising or effects independent of food advertising. Technological advances have allowed for greater accessibility and exposure to advertisement-free screen-based media. This review was conducted to systematically synthesise the evidence from laboratory based studies which have investigated the non-advertising effects of screen time (TV viewing, sedentary video games, and computer use) on dietary intake in children, adolescents, and young adults. MEDLINE, PubMed, PsychInfo, CINAHL, and Embase were searched from inception through 5 July 2013. Ten trials met the inclusion criteria and were included in the review. Risk of study bias was judged to range from low to high. Screen time in the absence of food advertising was consistently found to be associated with increased dietary intake compared with non-screen behaviours. Suggested explanations for this relationship included: distraction, interruption of physiologic food regulation, screen time as a conditioned cue to eat, disruption of memory formation, and the effects of the stress-induced reward system. Due to the limited number of high-quality studies available for this review, our findings are preliminary. More work is required to better establish the link between dietary intake and advertisement-free screen time and assess whether differences exist between the different screen-based activities.