Modelling the potential health and economic benefits of reducing population sitting time in Australia.

BACKGROUND: Strong evidence indicates that excessive time spent sitting (sedentary behaviour) is detrimentally associated with multiple chronic diseases. Sedentary behaviour is prevalent among adults in Australia and has increased during the COVID-19 pandemic. Estimating the potential health benefits and healthcare cost saving associated with reductions in population sitting time could be useful for the development of public health initiatives. METHODS: A sedentary behaviour model was developed and incorporated into an existing proportional, multi-state, life table Markov model (ACE-Obesity Policy model). This model simulates the 2019 Australian population (age 18 years and above) and estimates the incidence, prevalence and mortality of five diseases associated with sedentary behaviour (type 2 diabetes, stroke, endometrial, breast and colorectal cancer). Key model inputs included population sitting time estimates from the Australian National Health Survey 2014-2015, healthcare cost data from the Australian Institute of Health and Welfare (2015) and relative risk estimates assessed by conducting literature reviews and meta-analyses. Scenario analyses estimated the potential change in disease incidence as a result of changes in population sitting time. This, in turn, resulted in estimated improvements in long term health outcomes (Health-adjusted life years (HALYs)) and healthcare cost-savings. RESULTS: According to the model, if all Australian adults sat no more than 4 h per day, the total HALYs gained would be approximately 17,211 with health care cost savings of approximately A$185 million over one year. Under a more feasible scenario, where sitting time was reduced in adults who sit 4 or more hours per day by approximately 36 min per person per day (based on the results of the Stand Up Victoria randomised controlled trial), potential HALYs gained were estimated to be 3,670 and healthcare cost saving could reach A$39 million over one year. CONCLUSIONS: Excessive sedentary time results in considerable population health burden in Australia. This paper describes the development of the first Australian sedentary behaviour model that can be used to predict the long term consequences of interventions targeted at reducing sedentary behaviour through reductions in sitting time. These estimates may be used by decision makers when prioritising healthcare resources and investing in preventative public health initiatives.

Did the increase in sitting time due to COVID-19 lead to obesity in adolescents?

INTRODUCTION: Since adolescent with obesity is closely linked with the incidence of cardiovascular disease, it is important to identify the factors that increase the prevalence of adolescent with obesity and prevent it early. This study aimed to examine which of the demographic and lifestyle factors including sitting hours per week for purposes other than study had the greatest influence on Korean adolescents with obesity during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: We used the Korean Youth Risk Behavior Web-based Survey (KYRBWS) data. The primary outcome was the relationship between sitting hours and obesity during and after the COVID-19 pandemic. Multiple logistic regression analysis was performed to examine which of the demographic and lifestyle factors including sitting hours per week for purposes other than study had the greatest influence on Korean adolescents' obesity status. RESULTS: The prevalence of obesity was significantly higher during the COVID-19 than before the COVID-19 (OR, 1.268, CI:1.232-1.305). There was a significant increase in the OR for sitting hours per week for purposes other than study (OR, 1.021, 95% CI, 1.019-1.024). Compared to low household income, the OR decreased for middle (OR = 0.798, 95% CI:0.77, 0.826) and high-income household students (OR, 0.833, 95% CI: 0.803-0.865). DISCUSSION/CONCLUSION: The results of this study confirmed the relationship between sit-ting hours and obesity in adolescents during the pandemic. To prevent adolescent with obesity, further studies are needed to focus on the importance of promoting health policy in adolescents to avoid the continuous rising of its prevalence and needed to understand whether the increase in obesity rates during the pandemic is a temporary trend.

Homes became the "everything space" during COVID-19: impact of changes to the home environment on children's physical activity and sitting.

BACKGROUND: During the 2020 UK COVID-19 lockdown restrictions, children spent almost all of their time at home, which had a significant influence on their physical activity (PA) and sedentary behaviour. This study aimed to: 1) determine changes to the social and physical environment at home and children's home-based sitting, PA, standing and sitting breaks as a result of the COVID-19 restrictions; and 2) examine associations between changes at home and children's movement behaviours. METHODS: One hundred and two children had their PA and sitting, standing and sitting breaks at home objectively measured pre-COVID-19 and during the first COVID-19 lockdown (June-July 2020). Children's parents (n = 101) completed an audit of their home physical environment and a survey on the home social environment at both time points. Changes in the home physical and social environment and behavioural outcomes were assessed using Wilcoxon signed ranked tests, paired t-tests, or chi-square. Repeated linear regression analyses examined associations between changes in homes and changes in the home-based behavioural outcomes. RESULTS: During COVID-19, households increased the amount of seated furniture and electronic media equipment at home. The number of books and PA equipment decreased and fewer parents enforced a screen-time rule. Children's preference for physical activities and socialising at home decreased. Time at home and sitting at home increased during COVID-19, whilst PA, standing and sitting breaks decreased. Both MVPA and TPA were positively associated with child preference for PA, and negatively associated with attending school. Sitting was negatively associated with child preference for PA and child preference for socialising at home. Media equipment was negatively associated with sitting breaks, whilst PA equipment was positively associated with standing. CONCLUSION: The COVID-19 restrictions forced children to spend almost all their time at home. Children's PA, standing, and sitting breaks at home declined during the restrictions, while sitting increased. Mostly negative changes occurred in homes, some of which impacted children's behaviours at home. To avoid the changes persisting post-lockdown, interventions are needed to reset and promote children's PA and discourage prolonged sitting time.

Effectiveness of an intervention for reducing sitting time and improving health in office workers: three arm cluster randomised controlled trial.

OBJECTIVES: To evaluate the effectiveness of an intervention, with and without a height adjustable desk, on daily sitting time, and to investigate the relative effectiveness of the two interventions, and the effectiveness of both interventions on physical behaviours and physical, biochemical, psychological, and work related health and performance outcomes. DESIGN: Cluster three arm randomised controlled trial with follow-up at three and 12 months. SETTING: Local government councils in Leicester, Liverpool, and Greater Manchester, UK. PARTICIPANTS: 78 clusters including 756 desk based employees in defined offices, departments, or teams from two councils in Leicester, three in Greater Manchester, and one in Liverpool. INTERVENTIONS: Clusters were randomised to one of three conditions: the SMART Work and Life (SWAL) intervention, the SWAL intervention with a height adjustable desk (SWAL plus desk), or control (usual practice). MAIN OUTCOMES MEASURES: The primary outcome measure was daily sitting time, assessed by accelerometry, at 12 month follow-up. Secondary outcomes were accelerometer assessed sitting, prolonged sitting, standing and stepping time, and physical activity calculated over any valid day, work hours, workdays, and non-workdays, self-reported lifestyle behaviours, musculoskeletal problems, cardiometabolic health markers, work related health and performance, fatigue, and psychological measures. RESULTS: Mean age of participants was 44.7 years, 72.4% (n=547) were women, and 74.9% (n=566) were white. Daily sitting time at 12 months was significantly lower in the intervention groups (SWAL -22.2 min/day, 95% confidence interval -38.8 to -5.7 min/day, P=0.003; SWAL plus desk -63.7 min/day, -80.1 to -47.4 min/day, P<0.001) compared with the control group. The SWAL plus desk intervention was found to be more effective than SWAL at changing sitting time (-41.7 min/day, -56.3 to -27.0 min/day, P<0.001). Favourable differences in sitting and prolonged sitting time at three and 12 month follow-ups for both intervention groups and for standing time for the SWAL plus desk group were observed during work hours and on workdays. Both intervention groups were associated with small improvements in stress, wellbeing, and vigour, and the SWAL plus desk group was associated with improvements in pain in the lower extremity, social norms for sitting and standing at work, and support. CONCLUSIONS: Both SWAL and SWAL plus desk were associated with a reduction in sitting time, although the addition of a height adjustable desk was found to be threefold more effective. TRIAL REGISTRATION: ISRCTN Registry ISRCTN11618007.

Severe COVID-19 correlates with lower mitochondrial cristae density in PBMCs and greater sitting time in humans.

An interaction between mitochondrial dynamics, physical activity levels, and COVID-19 severity has been previously hypothesized. However, this has not been tested. We aimed to compare mitochondrial morphology and cristae density of PBMCs between subjects with non-severe COVID-19, subjects with severe COVID-19, and healthy controls. Additionally, we compared the level of moderate-vigorous physical activity (MVPA) and sitting time between groups. Blood samples were taken to obtain PBMCs. Mitochondrial dynamics were assessed by electron microscopy images and western blot of protein that regulate mitochondrial dynamics. The International Physical Activity Questionnaire (IPAQ; short version) was used to estimate the level of MVPA and the sitting time The patients who develop severe COVID-19 (COVID-19++) not present alterations of mitochondrial size neither mitochondrial density in comparison to non-severe patients COVID-19 (COVID-19) and control subjects (CTRL). However, compared to CTRL, COVID-19 and COVID-19++ groups have lower mitochondrial cristae length, a higher proportion of abnormal mitochondrial cristae. The COVID-19++ group has lower number (trend) and length of mitochondrial cristae in comparison to COVID-19 group. COVID-19, but not COVID-19++ group had lower Opa 1, Mfn 2 and SDHB (Complex II) proteins than CTRL group. Besides, COVID-19++ group has a higher time sitting. Our results show that low mitochondrial cristae density, potentially due to physical inactivity, is associated with COVID-19 severity.

Physical activity and sitting time changes in response to the COVID-19 lockdown in England.

To reduce the spread of the novel coronavirus disease 2019 (COVID-19), national governments implemented measures to limit contact between citizens. This study evaluated changes in physical activity and sitting in response to the first COVID-19 lockdown in England and factors associated with these changes. A cross-sectional online survey-based study collected data from 818 adults between 29 April and 13 May 2020. Participants self-reported demographic information, physical activity and sitting for a 'typical' week before and during lockdown. Participants were grouped into low, moderate and high physical activity, and low and high (≥8 hours/day) sitting. Paired samples t-tests compared physical activity (MET-min/week) before and during lockdown. Pearson's Chi-squared evaluated the proportion of participants in the physical activity and sitting categories. Logistic regression explored associations of demographic and behavioural factors with physical activity and sitting during lockdown. Walking and total physical activity significantly increased during lockdown by 241 (95% confidence interval [CI]: 176, 304) MET-min/week and 302 (CI: 155, 457) MET-min/week, respectively (P < 0.001). There was a 4% decrease in participants engaging in low physical activity and a 4% increase in those engaging in high physical activity from before to during lockdown (P < 0.001). The proportion engaging in high sitting increased from 29% to 41% during lockdown (P < 0.001). Lower education level (odds ratio [OR] = 1.65, P = 0.045) and higher BMI (OR = 1.05, P = 0.020) were associated with increased odds of low physical activity during lockdown, whereas non-White ethnicity (OR = 0.24, P = 0.001) was associated with reduced odds. Younger age was associated with increased odds of high sitting (OR = 2.28, P = 0.008). These findings suggest that physical activity and sitting both increased during lockdown. Demographic and behavioural factors associated with low physical activity and high sitting have been identified that could inform intervention strategies during situations of home confinement.

Influence of Sit-Stand Tables in Classrooms on Children's Sedentary Behavior and Teacher's Acceptance and Feasibility: A Mixed-Methods Study.

Children spend over 70% of their school day sitting, most of the time in the classroom. Even when meeting physical activity guidelines but sitting for long uninterrupted periods, children are at risk of poorer health outcomes. With an approach to create an active learning environment through the implementation of sit-stand tables, this exploratory mixed-methods study aims to evaluate a holistic concept for reducing sedentary time in schools by implementing sit-stand tables as well as to examine the feasibility and didactic usability in classroom settings. Children from eight German schools aged 7 to 10 in primary schools and 11 to 13 in secondary schools (n = 211), allocated into control and intervention groups, were included in the study, as well as teachers (n = 13). An accelerometer was used as a quantitative measure to assess sitting and standing times and sport motoric tests were taken. Qualitative interviews were performed with teachers regarding feasibility and acceptance of the sit-stand tables. Independent t-test analysis adjusted for age, sex and school type found that sitting times of children in the intervention group could be reduced (by 30.54 min per school day of 6 h, p < 0.001) within all school and age levels. Overall, implementing sit-stand tables in classrooms serves as a feasible and effective opportunity to reduce sedentary behaviour and create an active learning environment.

Levels and Correlates of Objectively Measured Sedentary Behavior in Young Children: SUNRISE Study Results from 19 Countries.

PURPOSE: There is a paucity of global data on sedentary behavior during early childhood. The purpose of this study was to examine how device-measured sedentary behavior in young children differed across geographically, economically, and sociodemographically diverse populations, in an international sample. METHODS: This multinational, cross-sectional study included data from 1071 children 3-5 yr old from 19 countries, collected between 2018 and 2020 (pre-COVID). Sedentary behavior was measured for three consecutive days using activPAL accelerometers. Sedentary time, sedentary fragmentation, and seated transport duration were calculated. Linear mixed models were used to examine the differences in sedentary behavior variables between sex, country-level income groups, urban/rural settings, and population density. RESULTS: Children spent 56% (7.4 h) of their waking time sedentary. The longest average bout duration was 81.1 ± 45.4 min, and an average of 61.1 ± 50.1 min·d-1 was spent in seated transport. Children from upper-middle-income and high-income countries spent a greater proportion of the day sedentary, accrued more sedentary bouts, had shorter breaks between sedentary bouts, and spent significantly more time in seated transport, compared with children from low-income and lower-middle-income countries. Sex and urban/rural residential setting were not associated with any outcomes. Higher population density was associated with several higher sedentary behavior measures. CONCLUSIONS: These data advance our understanding of young children's sedentary behavior patterns globally. Country income levels and population density appear to be stronger drivers of the observed differences, than sex or rural/urban residential setting.

Working from home during the COVID-19 pandemic and its longitudinal association with physical activity and sedentary behavior.

OBJECTIVE: Working from home during the COVID-19 pandemic has affected many workers' daily life and possibly their physical activity behavior. We studied the longitudinal association of working from home during the pandemic with physical activity and sedentary behavior. METHODS: Longitudinal data from 17 questionnaire rounds of the Lifelines COVID-19 cohort (March 2020-February 2021) were used. In total, 33 325 workers were included. In every round, participants reported their current work situation: location, home, or hybrid (working on location and from home). Physical activity levels and sedentary behavior before and during the pandemic were asked. Logistic generalized estimating equations adjusted for demographic/work/health covariates were used to study the association of work situation with physical activity and sedentary behavior. RESULTS: Home workers were less likely to meet the recommended ≥150 minutes/week of moderate-to-vigorous-intensity activity during the pandemic than location workers [odds ratio (OR) 0.93, 95% confidence interval (CI) 0.90-0.96] and more likely to be less physically active than before the pandemic (OR 1.09, 95% CI 1.04-1.14). Furthermore, compared to location workers, home and hybrid workers were more likely to be more sedentary (sitting ≥8 hours/day) on workdays during than before the pandemic (OR 1.51, 95% CI 1.39-1.64/1.36-1.68, respectively). CONCLUSIONS: Compared to location workers, home workers (and to a lesser extent hybrid workers) were more often physically inactive and sedentary during than before the COVID-19 pandemic. As a substantial part of the working population may continue to work (partly) from home after the pandemic, workers should be supported to increase activity and reduce sitting while working from home.

Time to active sitting position: One-year findings from a temporary COVID-19 intensive care unit.

OBJECTIVE: To investigate the association between time to active sitting position and clinical features in people with COVID-19 admitted to intensive care unit (ICU) and referred to physiotherapists. METHOD: Prospective study conducted in the largest temporary ICU in Lombardy (Italy) between April 2020 and June 2021. All individuals with COVID-19 who received physiotherapy were included. Multivariable Cox proportional hazard model was fitted to explore the statistical association between active sitting position and characteristics of patients referred to physiotherapists, also accounting for the different multidisciplinary teams responsible for patients. RESULTS: 284 individuals over 478 (59.4%) had access to physiotherapy, which was performed for a median of 8 days, without difference between multidisciplinary teams (P = 0.446). The active sitting position was reached after a median of 18 (IQR: 10.0-32.0) days. Sex was the only characteristic associated with the time to active sitting position, with males showing a reduced hazard by a factor of 0.65 (95% CI: 0.48-0.87; P = 0.0042) compared to females. At ICU discharge, nearly 50% individuals increased Manchester Mobility Score by 3 points. During physiotherapy no major adverse event was recorded. CONCLUSION: Individuals with COVID-19 take long time to reach active sitting position in ICU, with males requiring longer rehabilitation than females.

Comparison of tracheal intubation between sitting position and standing position in COVID-19 patients: A manikin study.

ABSTRACT: It is recommended to use visual laryngoscope for tracheal intubation in a Corona Virus Disease 2019 patient to keep the operator farther from the patient. How the position of the operator affects the distance in this setting is not ascertained. This manikin study compares the distances between the operator and the model and the intubation conditions when the operator is in sitting position and standing position, respectively.Thirty one anesthesiologists with minimum 3-years' work experiences participated in the study. The participant's posture was photographed when he performed tracheal intubation using UE visual laryngoscope in standing and sitting position, respectively. The shortest distance between the model's upper central incisor and operator's face screen (UF), the horizontal distance between the model's upper central incisor and the operator's face screen, the angle between the UF line and the vertical line of the model's upper central incisor were measured. The success rate of intubation, the duration of intubation procedure, the first-attempt success rate, the Cormack-Lehane grade, and operator comfort score were also recorded.When the operator performed the procedure in sitting position, the horizontal distance between the model's upper central incisor and the operator's face screen distance was significantly longer (9.5 [0.0-17.2] vs 24.3 [10.3-33.0], P ≤ .001) and the angle between the UF line and the vertical line of the model's upper central incisor angle was significantly larger (45.2 [16.3-75.5] vs 17.7 [0.0-38.9], P ≤ .001). There was no significant difference in UF distance when the operator changed the position. Cormack-Lehane grade was significantly improved when it was assessed using visual laryngoscope. Cormack-Lehane grade was not significantly different when the operator assessed it in sitting and standing position, respectively. No significant differences were found in the success rate, duration for intubation, first-attempt success rate, and operator comfort score.The operator is kept farther from the patient when he performs intubation procedure in sitting position. Meanwhile, it does not make the procedure more difficult or uncomfortable for the operator, though all the participants prefer to standing position.

A method for remotely measuring physical function in large epidemiologic cohorts: Feasibility and validity of a video-guided sit-to-stand test.

INTRODUCTION: Traditional measures of muscular strength require in-person visits, making administration in large epidemiologic cohorts difficult. This has left gaps in the literature regarding relationships between strength and long-term health outcomes. The aim of this study was to test the feasibility and validity of a video-led, self-administered 30-second sit-to-stand (STS) test in a sub-cohort of the U.S.-based Cancer Prevention Study-3. METHODS: A video was created to guide participants through the STS test. Participants submitted self-reported scores (n = 1851), and optional video recordings of tests (n = 134). Two reviewers scored all video tests. Means and standard deviations (SD) were calculated for self-reported and video-observed scores. Mean differences (95% confidence intervals (CI)) and Spearman correlation coefficients between self-reported and observed scores were calculated, stratifying by demographic characteristics. RESULTS: Participants who uploaded a video reported 14.1 (SD = 3.5) stands, which was not significantly different from the number of stands achieved by the full cohort (13.9 (SD = 4.2), P-difference = 0.39). Self-reported and video-observed scores were highly correlated (ρ = 0.97, mean difference = 0.3, 95% CI = 0.1-0.5). There were no significant differences in correlations by sociodemographic factors (all P-differences ≥0.42). CONCLUSIONS: This study suggests that the self-administered, video-guided STS test may be appropriate for participants of varying ages, body sizes, and activity levels, and is feasible for implementation within large, longitudinal studies. This video-guided test would also be useful for remote adaptation of the STS test during the COVID-19 pandemic.

A systematic review and meta-analysis of the effect of treadmill desks on energy expenditure, sitting time and cardiometabolic health in adults.

BACKGROUND: As the health risks of sedentary working environments become more clear, greater emphasis on the implementation of walking interventions to reduce sitting time is needed. In this systematic review and meta-analysis, we investigate the role of treadmill-desk interventions on energy expenditure, sitting time, and cardiometabolic health in adults with sedentary occupations. METHODS: Relevant studies published in English were identified using CINAHL, EMBASE, MEDLINE, Web of Science, Scopus, and PubMed databases up to December 2020. Random effects meta-analysis models were used to pool study results. RESULTS: Thirteen relevant studies (six workplaces and seven laboratories) were found with a total of 351 participants. Pooled analysis of laboratory studies showed a significant increase in energy expenditure (105.23 kcal per hour, 95% confidence interval [CI]: 90.41 to 120.4), as well as metabolic rate (5.0 mL/kg/min, 95% CI: 3.35 to 6.64), among treadmill desk users compared to sitting conditions. No evidence of significant differences in blood pressure were found. In workplace studies, we observed a significant reduction in sitting time over a 24-h period (- 1.73 min per hour, 95% CI: - 3.3 to - 0.17) among users of treadmill desks, compared to a conventional desk. However, there were no evidence of statistically significant changes in other metabolic outcomes. CONCLUSIONS: Treadmill desks offer a feasible and effective intervention to increase energy expenditure and metabolic rate and reduce sitting time while performing work-related tasks. Future studies are needed to increase generalizability to different workplace settings and further evaluate their impact on cardiometabolic health.

Association between physical and mental health variables among software professionals working at home: a secondary analysis.

The association of physical activity (PA) or sedentary behaviour (SB) with mental health in remotely working software professionals remains unclear. We administered a secondary analysis of physical health variables (PA and SB time during work and non-work days) and mental health variables (stress, anxiety, depression) from a primary study. Ninety-five per cent of the participants (n = 76) did not meet the global PA recommendations. Our study found daily PA time to be negatively associated with stress (ß = -1.57; p = 0.02), anxiety (ß = -1.01; p = 0.04) and depression (ß = -0.68; p = 0.47). Furthermore, the average daily sitting time during the work day was found to be positively associated with stress (ß = 0.28; p = 0.00), anxiety (ß = 0.01; p = 0.04) and depression (ß = -0.68; p = 0.03). Organizational policies should advocate the implementation of PA or SB strategies for improving mental health in remote workers.Trial registrationClinical Trials Registry India identifier CTRI/2021/03/032146.

Changes to Physical Activity, Sitting Time, Eating Behaviours and Barriers to Exercise during the First COVID-19 'Lockdown' in an English Cohort.

This study aimed to determine the effect of the first English national COVID-19 lockdown on physical activity (PA), sitting time, eating behaviours and body mass in an adult cohort. This was further examined to determine whether conforming to recommended guidelines on PA and sedentary behaviour was improved. Based on an online survey (n = 818) incorporating the International Physical Activity Questionnaire Short Form (IPAQ-SF), self-reported body mass change showed that in 32.2% of participants body mass increased, with 39.1% reporting an increase in food intake. Never exercising at the gym or undertaking an exercise class (online or live), increased by 50.8% during lockdown, with 53.5% changing from exercising frequently to never exercising, suggesting a lack of engagement with online and home workouts. However, outdoor running and cycling >2 times/week increased by 38% during lockdown. Walking at least 30 min continuously on >2 occasions/week increased by 70% during lockdown with minimum 10-min walks on 7 days per week increasing by 23%. The lockdown had a negative impact on sitting time (>8 h a day), which increased by 43.6% on weekdays and 121% at weekends. Furthermore, sitting <4 h/day decreased during lockdown (46.5% and 25.6% for weekdays and weekends, respectively). Those citing tiredness or lack of time as a barrier to exercise reduced by 16% and 60%, respectively, from pre-lockdown to during lockdown. More of the sedentary group met the Public Health England PA recommendations, however most participants still did not meet the UK Government guidelines for PA. Improvements in health per additional minutes of physical activity will be proportionately greater in those previously doing <30 min/week, the area where most improvements were found although, conversely sitting time was greatly increased. This study may assist in informing whether future lifestyle changes could improve the health of the population.

Associations between Physical Activity, Sitting Time, and Time Spent Outdoors with Mental Health during the First COVID-19 Lock Down in Austria.

Measures implemented to reduce the spread of SARS-CoV-2 have resulted in a decrease in physical activity (PA) while sedentary behaviour increased. The aim of the present study was to explore associations between PA and mental health in Austria during COVID-19 social restrictions. In this web-based cross-sectional study (April-May 2020) moderate-to-vigorous physical activity (MVPA), sitting time, and time spent outdoors were self-reported before and during self-isolation. Mental well-being was assessed with the Warwick-Edinburgh Mental Well-being Scale, and the Beck depression and anxiety inventories. The majority of the participants (n = 652) were female (72.4%), with a mean age of 36.0 years and a standard deviation (SD) of 14.4. Moreover, 76.5% took part in ≥30 min/day of MVPA, 53.5% sat ≥10 h/day, and 66.1% spent ≥60 min/day outdoors during self-isolation. Thirty-eight point five percent reported high mental well-being, 40.5% reported depressive symptoms, and 33.9% anxiety symptoms. Participating in higher levels of MVPA was associated with higher mental well-being (odds ratio = OR: 3.92; 95% confidence interval = 95%CI: 1.51-10.15), less depressive symptoms (OR: 0.44; 95%CI: 0.29-0.66) and anxiety symptoms (OR = 0.62; 95%CI: 0.41-0.94), and less loneliness (OR: 0.46; 95%CI: 0.31-0.69). Participants sitting <10 h/day had higher odds of mental well-being (OR: 3.58; 95%CI: 1.13-11.35). Comparable results were found for spending ≥60 min/day outdoors. Maintaining one's MVPA levels was associated with higher mental well-being (OR = 8.61, 95%CI: 2.68-27.62). In conclusion, results show a positive association between PA, time spent outdoors and mental well-being during COVID-19 social restrictions. Interventions aiming to increase PA might mitigate negative effects of such restrictions.

Transient and continuous effects of indoor human movement on nanoparticle concentrations in a sitting person's breathing zone.

Particle concentration in a sitting person's breathing zone can be influenced by human movement around the person, and the transient and continuous effects may differ. In this study, a set of full-scale experiments was conducted to sample the nanoparticle concentration in the breathing zone of a sitting thermal breathing manikin (STBM). The transient fluctuation of the nanoparticle concentration was recorded continuously and analyzed. The results showed that when a manikin moved (at 1 m/s) past the STBM, the nanoparticle concentration in the STBM's breathing zone decreased and reached its lowest after the standing manikin had passed, decreasing 37.6 (±5.7) % compared with the peak value. The average concentration in the STBM's breathing zone during influence periods was 5.18 (±0.99) % less than that during non-influence Periods (NP). This finding reflected the fact that the transient inhalation (over several seconds) of the STBM may be reduced by manikin movement. On the other hand, the exposure of the STBM increased 2.88 (±1.24) % when there was a continuously moving manikin compared with the stable state in a 10-min observation. This finding may be explained by the fuller mix of indoor air and nanoparticles caused by manikin movement, as well as the increase of nanoparticle suspension time. The difference in the transient and continuous effects of the manikin movement on the STBM's exposure shows the importance of considering these effects separately in different scenarios.

Validity of the occupational sitting and physical activity questionnaire (OSPAQ) for home-based office workers during the COVID-19 global pandemic: A secondary analysis.

High levels of occupational sitting is an emerging health concern. As working from home has become a common practice as a result of COVID-19, it is imperative to validate an appropriate self-report measure to assess sitting in this setting. This secondary analysis study aimed to validate the occupational sitting and physical activity questionnaire (OSPAQ) against an activPAL4™ in full-time home-based 'office' workers (n = 148; mean age = 44.90). Participants completed a modified version of the OSPAQ and wore an activPAL4™ for a full work week. The findings suggest that the modified OSPAQ has fair levels of validity in terms of correlation for sitting and standing (ρ = 0.35-0.43, all p < 0.05) and agreement (bias = 2-12%) at the group level; however, estimates were poor at an individual level, as suggested by wide limits of agreement (±22-30%). Overall, the OSPAQ showed to be an easily administered and valid questionnaire to measure group level sitting and standing in this sample of adults.

Sitting for long periods is associated with impaired work performance during the COVID-19 pandemic.

OBJECTIVES: The unprecedented coronavirus disease 2019 (COVID-19) pandemic and the corresponding government state of emergency have dramatically changed our workstyle, particularly through implementing teleworking and social distancing. We investigated the degree to which people's work performance is affected and the association between sedentary behavior under the state of emergency and worsened work performance during the COVID-19 pandemic, as previous studies have suggested that sedentary behavior decreases work performance. METHODS: We used data from the Japan "COVID-19 and Society" Internet Survey (JACSIS) study, a cross-sectional, web-based, self-reported questionnaire survey. The main outcome was change in work performance after the COVID-19 pandemic compared with that before the pandemic. We analyzed the association between the change in work performance and sitting duration under the state of emergency, adjusted for work-related stress, participants' demographics, socio-economic status, health-related characteristics, and personality. RESULTS: The change of work environment from the pandemic decreased work performance in 15% of workers, which was 3.6 times greater than the number of workers reporting increased performance in 14 648 workers (6134 women and 8514 men). Although telework both improved and worsened performance (odds ratio [OR], 95% confidence interval [CI] = 2.0, 1.6-2.5 and 1.7, 1.5-1.9, respectively), sitting for long periods after the state of emergency was significantly associated only with worsened performance (OR, 95% CI = 1.8, 1.5-2.2) in a dose-response manner. CONCLUSION: Sitting duration is likely a risk barometer of worsened work performance under uncertain working situations, such as the COVID-19 pandemic.