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- Abbott, Rebecca, et al.
(författare)
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Patterning of children's sedentary time at and away from school
- 2013
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Ingår i: Obesity. - : Wiley. - 1930-7381 .- 1930-739X. ; 21, s. E131-E133
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Tidskriftsartikel (refereegranskat)abstract
- Objective:Sedentary behavior in children is positively associated with an increased risk of both obesity and insulin resistance. Children spend a considerable portion of their awake time in sedentary behavior; however, the pattern of accumulation is not known. Thus the objective of this study was to describe the patterning of sedentary behavior of children at and away from school.Design and Methods:The patterns of sedentary time in a sample of 53 children (28 girls) aged 10-12 years during school-term time were examined. Children wore an accelerometer for 1 week. Total sedentary time, prolonged sequences (bouts) of sedentary time, and frequency of active interruptions to sedentary were examined on school days and weekends and within school time and non-school time on school days.Results:The data did not support our hypothesis that children accumulated more sedentary time on school days when compared with weekend days (mean [SD]: 64.4% [5.3] vs. 64.9% [9.0], P = 0.686). However, when comparing school time with non-school time on school days, children accumulated more sedentary time at school (66.8% [7.3] vs. 62.4% [5.2], P < 0.001) and spent more time at school in sustained sedentary sequences, that is, uninterrupted sedentary time for 30 min or more (75.6 min [45.8] vs. 45.0 min [26.8], P < 0.002). The children also recorded less breaks per sedentary hour within school time when compared with non-school time (8.9 h−1 vs. 10.2 h−1, P < 0.001).Conclusion:Reducing total sedentary time spent both in and out of school remains an important challenge. Interrupting sedentary time more often in the “working” (school) day could also reap important musculoskeletal and metabolic health rewards for children.
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| 2. |
- Straker, Leon, et al.
(författare)
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Capturing the pattern of activity : Exposure variation analysis of accelerometer data
- 2012
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Ingår i: 4th International Congress on Physical Activity and Public Health, Australian Conference of Science and Medicine in Sport, National Sports Injury Prevention Conference Abstracts. - : Elsevier BV. ; , s. S94-S94
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Konferensbidrag (refereegranskat)abstract
- Purpose: Physical activity, in particular moderate to vigorous physical activity (MVPA), sedentary behaviour (SB) are known to impact on health. Less well established is how patterning of activity affects health. Capturing the complex time pattern of activity using accelerometry remains a challenge. Occupational health research suggests Exposure Variation Analysis (EVA) could provide a useful tool. The purpose of this paper is to 1) explain the application of EVA to accelerometer data, 2) demonstrate how EVA thresholds, derivatives could be chosen, used to examine adherence to MVPA, SB guidelines, 3) explore the validity of EVA outputs.Methods: EVA reduces a complex time-line of exposure into a two-dimensional matrix showing combinations of exposure level (in categories) and duration of uninterrupted sequences (in categories). Data from 4 individuals with different daily activity patterns were collected to demonstrate the applicability of EVA. EVA outputs were also compared for accelerometer data collected from 3 occupational groups with known different activity patterns: seated workstation office workers, standing workstation office workers and teachers. Standard accelerometer data collection procedures were used. Data processing by a custom LabVIEW program calculated EVA matrices and derivatives aligned to common guidelines.Results: Data from one individual is presented in a time-based line graph form in conjunction with the resultant EVA matrix and EVA graph. Line graphs and related EVA graphs for 3 further individuals highlight the use of EVA derivatives for examining compliance with MVPA and SB guidelines. For the seated office workers, standing office workers and teachers, analyses confirm no difference in bouts of MVPA but very clear differences as expected in extended bouts of SB and brief bursts of activity, thus providing evidence of construct validity of the EVA approach.Conclusion: The major advantage of EVA is its ability in a single analysis to simultaneously capture the time pattern of activity at various levels of intensity according to the choice of the researcher. Whilst presented here with four levels of intensity, sedentary, light, moderate and vigorous, EVA could be utilised with dichotomous data such as sitting vs standing, or adjusted to match future refinements of activity guidelines. EVA offers a unique and comprehensive generic method that is ideal for processing large quantities of accelerometer data. EVA is able, for the first time, to concisely capture the time pattern (both frequency and intensity) of activity, and can be tailored for both occupational and public health research.
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| 3. |
- Straker, Leon, et al.
(författare)
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Capturing the pattern of physical activity and sedentary behavior : Exposure Variation Analysis of accelerometer data
- 2014
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Ingår i: Journal of Physical Activity and Health. - : Human Kinetics. - 1543-3080 .- 1543-5474. ; 11:3, s. 614-625
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Capturing the complex time pattern of physical activity (PA) and sedentary behavior (SB) using accelerometry remains a challenge. Research from occupational health suggests exposure variation analysis (EVA) could provide a meaningful tool. This paper (1) explains the application of EVA to accelerometer data, (2) demonstrates how EVA thresholds and derivatives could be chosen and used to examine adherence to PA and SB guidelines, and (3) explores the validity of EVA outputs.METHODS: EVA outputs are compared with accelerometer data from 4 individuals (Study 1a and1b) and 3 occupational groups (Study 2): seated workstation office workers (n = 8), standing workstation office workers (n = 8), and teachers (n = 8).RESULTS: Line graphs and related EVA graphs highlight the use of EVA derivatives for examining compliance with guidelines. EVA derivatives of occupational groups confirm no difference in bouts of activity but clear differences as expected in extended bouts of SB and brief bursts of activity, thus providing evidence of construct validity.CONCLUSIONS: EVA offers a unique and comprehensive generic method that is able, for the first time, to capture the time pattern (both frequency and intensity) of PA and SB, which can be tailored for both occupational and public health research.
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| 4. |
- Straker, Leon, et al.
(författare)
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Sit-stand desks and sedentary behavior in Swedish call centre workers
- 2012
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Ingår i: Be active 2012. - : Elsevier BV. ; , s. S94-
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Konferensbidrag (refereegranskat)abstract
- Introduction: Adults spend approximately 8 to 9 hours of the day in sedentary behavior and much of this is gathered at work. The rising level of occupational sedentary behavior is both a public health and occupational health concern due to the emerging evidence regarding the deleterious effect that sedentary behavior has on health, independent of physical activity. In the occupational setting, sit-stand desks have been purported to offer a means of reducing sedentariness. This study aimed to investigate whether or not use of sit-stand desks and awareness of the importance of postural variation and breaks are associated with the pattern of sedentary behavior in call centre workers.Method: The data came from a cross-sectional observation study of fifteen Swedish call centres, carried out in 2002–2003. Ten operators were randomly selected from each of the call centres and invited to participate. Inclinometers recorded ‘seated’ or ‘standing/walking’ episodes of the operators over a full work shift. Differences in sedentary behavior based on desk type (categorized as ‘sit-stand’ or ‘sit’) and awareness of the importance of posture variation and breaking up seated computer work within those using a sit-stand desk were assessed by non-parametric analyses.Results: Four operators declined to participate and 15 operators had inclinometer recordings that were not of sufficient quality. Of the remaining 131 operators, 90 (68.7%) worked at a sit-stand desk. Working at a sit-stand desk, as opposed to a sit desk, was associated with a modest reduction in the time seated (78.5 vs 83.8%, p = 0.010), and less time taken to accumulate 5 minutes of standing/walking (36.2 vs 46.3 minutes, p = 0.022), but no significant difference to sitting episode length or the number of switches between sitting and standing/walking per hour. Ergonomics awareness had no significant association with any sedentary behavior pattern variable among those using a sit-stand desk.Conclusion: Use of sit-stand desks was associated with better sedentary behavior in call centre workers, however ergonomics awareness did not enhance the effect. The growing number of people in occupations dominated by sedentary work and the clear evidence of the importance of sedentary behavior as a key lifestyle risk factor support the need to develop effective interventions. Sit-stand desks may be an important remedy in this endeavor, particularly in office settings, while ergonomics awareness may be able to contribute to further changes in sedentary behavior if improved and supported by the work organization.
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| 5. |
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| 6. |
- Straker, Leon, et al.
(författare)
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Sit-stand desks in call centres : associations of use and ergonomics awareness with sedentary behavior
- 2013
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Ingår i: Applied Ergonomics. - : Elsevier BV. - 0003-6870 .- 1872-9126. ; 44:4, s. 517-522
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Sedentary behavior is an independent risk factor for obesity, diabetes, and all cause mortality. With adults in occupational settings spending two thirds or more of their time in sedentary behavior, novel strategies are required to intervene with occupational sitting. To investigate whether or not use of sit-stand desks and awareness of the importance of postural variation and breaks are associated with the pattern of sedentary behavior in office workers.Method. The data came from a cross-sectional observation study of Swedish call centre workers. Inclinometers recorded ‘seated’ or ‘standing/walking’ episodes of 131 operators over a full work shift. Differences in sedentary behavior based on desk type and awareness of the importance of posture variation and breaks were assessed by non-parametric analyses.Results. 90 (68.7%) operators worked at a sit-stand desk. Working at a sit-stand desk, as opposed to a sit desk, was associated with less time seated (78.5 vs 83.8%, p=0.010), and less time taken to accumulate 5 minutes of standing/walking (36.2 vs 46.3 minutes, p=0.022), but no significant difference to sitting episode length or the number of switches between sitting and standing/walking per hour. Ergonomics awareness was not associated with any sedentary pattern variable among those using a sit-stand desk.Conclusion. Use of sit-stand desks was associated with better sedentary behavior in call centre workers, however ergonomics awareness did not enhance the effect. Further investigation into how best to intervene with occupational sitting is required.
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| 7. |
- Straker, Leon, et al.
(författare)
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Teaching our children to sit or be active? Sedentary behavior, light activity and moderate/vigorous activity at and away from school
- 2012
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Ingår i: 4th International Congress on Physical Activity and Public Health, Australian Conference of Science and Medicine in Sport, National Sports Injury Prevention Conference Abstracts. - : Elsevier BV. ; , s. S280-
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Konferensbidrag (refereegranskat)abstract
- Introduction: Sedentary behavior in children is associated with poor health whilst moderate/vigorous activity is associated with better health. The school setting may be an opportunity to reduce sedentariness and enhance physical activity, yet concerns have been raised that children may be more sedentary at school. This paper examined activity patterns, including both sedentary time and time in health enhancing physical activity, in children across their typical week.Methods: Sixty-six 10–12 year old children were recruited from 48 schools in the Perth metropolitan area as part of a randomized controlled study (Australia and New Zealand Clinical Trials Registry ACTRN 12609000279224) investigating the effects of electronic games on physical activity. The data for this paper come from their baseline assessment, which all occurred during school term time. Children wore an Actical accelerometer on their hip for one week. Time spent in sedentary, light, moderate and vigorous physical activity was assessed. School day and weekend day activity patterns were examined along with activity patterns both in (school time) and out of school (non-school-time) on school days.Results: Valid (at least 4 days) accelerometer data were available on 53 children (28 girls). The average time of accelerometer recording per day was 822 ± 71 minutes (13.7 hours). Accumulated time in sedentary behavior was similar on school days and weekend days (mean [SD]: 64.4%[5.3] vs 64.9%[9.0], p = 0.686). Children were more likely to reach physical activity guidelines on school days than at the weekend (47.7% v 22.2%, p < 0.001) and spend more time in brief–less than 5 minutes–bursts of activity of any intensity (35.3%[5.1] vs 32.6%[6.9], p = 0.002). However, children spent a higher proportion of time in sedentary behavior (66.8%[7.3] vs 62.4%[5.2], p < 0.001), and significantly more time in extended sedentariness–sedentary for more than thirty minutes or more (75.6mins[45.8] vs 45.0 mins[26.8], p < 0.002)–within school time compared to non-school time.Discussion: Children spent a considerable proportion of their school or non-school day in sedentary behavior, and routinely spent over two hours of each day in extended sedentary behavior. School should be a place where children learn healthful habits, and whilst it appears to be associated with better moderate/vigorous physical activity exposure it was associated with poorer extended sedentary exposure. Increasing moderate/vigorous physical activity and reducing time spent in sedentary behavior both in and out of school remains an important challenge.
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