The "sweet- and sour-spot" of occupational physical activity for back pain: a prospective accelerometer study among eldercare workers.

OBJECTIVES: Both high and low levels of occupational physical activity are associated with back pain. Thus, there might be a "sweet- and sour-spot" of occupational physical activity for back pain. Our aim was to investigate if there exists an occupational physical activity "sweet- (lowest risk) and sour-spot" (highest risk) for back pain. METHODS: A total of 396 eldercare workers from 20 Danish nursing homes participated. Occupational physical activity was measured between 1-4 working days using thigh-worn accelerometry. Back pain intensity was reported monthly on a scale from 0-10 over 1-year. A zero-inflated mixed-effects model was developed regressing occupational physical activity against back pain, adjusted for confounders. The "sweet- and sour-spot" were defined as the occupational physical activity compositions (sitting, standing, light, and moderate-to-vigorous) associated with the 5% lowest and highest risk for back pain, respectively. RESULTS: The composition associated with the lowest risk of back pain - the "sweet-spot"- consisted of 71% worktime spent sitting, 18% spent standing, 5% spent on light physical activity and 6% spent on moderate-to-vigorous physical activity. The composition associated with highest risk for back pain -the "sour-spot"- consisted of 8% worktime spent sitting, 66% spent standing, 4% spent on light physical activity, and 21% spent on moderate-to-vigorous physical activity. CONCLUSIONS: The "sweet-spot" of occupational physical activity for back pain among eldercare workers involves more sitting and light physical activity time, while the "sour-spot" involves more standing and moderate-to-vigorous physical activity time. Research on the occupational physical activity "sweet- and sour-spot" is needed.

Is patients' activities of daily living self-care score in Norwegian home care a proxy for workers standing at work?

BACKGROUND: Prolonged standing at work may contribute to increased risk of musculoskeletal pain in home care workers. Patients' activities of daily living (ADL) score may be a proxy for home care workers' standing time at work. The objective of the present study was to investigate the association between patients' ADL self-care score, and workers standing time. METHODS: This cross-sectional study measured time spent standing, sitting and in physical activity for seven days using thigh-worn accelerometers, among 14 home care workers. Patients' ADL self-care scores are routinely adjusted by home care nurses, and time intervals of home care visits are stored in home care services electronic patient journal. We collected ADL self-care scores and start and end time points of visits, and categorized ADL self-care scores as low (ADL ≤ 2.0), medium (ADL > 2.0 to 3.0) or high (ADL > 3.0). Physical behavior data were transformed to isometric log-ratios and a mixed-effect model was used to investigate differences in physical behavior between the three ADL self-care score categories. RESULTS: We analyzed 931 patient visits and found that high ADL self-care scores were associated with longer standing times relative to sitting and physical activity, compared to low ADL score (0.457, p = 0.001). However, no significant differences in time spent standing were found between high and medium ADL patient visits (0.259, p = 0.260), nor medium and low (0.204, p = 0.288). High ADL score patients made up 33.4% of the total care time, despite only making up 7.8% of the number of patients. CONCLUSION: Our findings suggest that caring for patients with high ADL self-care score requires workers to stand for longer durations and that this group of patients constitute a significant proportion of home care workers' total work time. The findings of this study can inform interventions to improve musculoskeletal health among home care workers by appropriate planning of patient visits.

Effectiveness of a Goldilocks Work intervention in childcare workers - A cluster-randomized controlled trial.

OBJECTIVE: Poor cardiorespiratory fitness and health is common among childcare workers. We designed the `Goldilocks-games` according to the Goldilocks Work principle to provide high-intensity physical activity for childcare workers. We investigated the effectiveness of this Goldilocks Work intervention in increasing occupational high-intensity physical activity and improving work-related health. METHODS: In a two-arm cluster randomized trial, 16 childcare institutions with 142 workers were randomly allocated to either an 8-week Goldilocks Work intervention or a control group. The primary outcome was occupational time in high-intensity physical activity. Secondary outcomes were occupational time in active physical behaviors, heart rate during sleep, pain, physical exhaustion, energy at work, work productivity, and need for recovery. RESULTS: The intervention was successfully delivered and received. Both groups had a low amount of occupational high-intensity physical activity at baseline, and the intervention group reported playing the games 3.1 [standard deviation (SD) 1.5] times/week for a duration of 112.2 (SD 175.0) min/week. However, the intervention did not increase high-intensity physical activity or the secondary outcomes, except for energy at work, measured on a scale from 0-10, increasing 0.65 [95% confidence interval (CI) 0.08-1.21], and need for recovery, measured on a scale from 1-5, decreasing -0.32 (95% CI, -0.54- -0.09). CONCLUSION: The intervention was successfully delivered and received, but did not increase high-intensity physical activity. The intervention group increased their energy at work and decreased their need for recovery, but not the other health-related outcomes. Further research on how to design and implement health-promoting work environment interventions in childcare is needed.

Physical activity dose for generalized anxiety disorder & worry: Results from the Irish longitudinal study on ageing.

The lowest moderate-to-vigorous physical activity (MVPA) dose that conveys protection for Generalized Anxiety Disorder (GAD) and worry is unknown. This study quantified associations of weekly accumulated MVPA doses with GAD and worry across 10 years using data from The Irish Longitudinal Study on Ageing (TILDA). Continuous MVPA (metabolic equivalent of task [MET] minutes per week [MET.min.week-1]; e.g., moderate-intensity brisk walking = 4METs), three-dose and, more precise, five-dose MVPA categories were examined. Worry symptoms and GAD status were measured using the Penn State Worry Questionnaire-Abbreviated and the Composite International Diagnostic Interview. Multivariable negative random effect binomial regression and logistic models adjusted for relevant covariates quantified associations across time. Among the 7,650 participants, compared to no MVPA (0 MET.min.week-1), 18 % (OR: 0.82; 95 %CI: [0.69-0.98]), 22 % (OR: 0.78; [ 0.64-0.95]) and 31 % (OR: 0.69; [0.59-0.79]) lower odds of GAD were found for the doses of 1-<600, 600-<1,200 and ≥2,400 MET.min.week-1 respectively. Post-hoc analysis demonstrated 47 % lower odds (OR: 0.53; (0.36-0.78) of GAD for 1-<200 MET.min.week1 compared to inactivity. Compared to no activity, engaging in even minimal physical activity equivalent of 10 min/day for five days/week of moderate-intensity activity (e.g., brisk walking), may lower the risk of GAD over time among older adults.

Objective Measurement of Posture and Movement in Young Children Using Wearable Sensors and Customised Mathematical Approaches: A Systematic Review.

Given the importance of young children's postures and movements to health and development, robust objective measures are required to provide high-quality evidence. This study aimed to systematically review the available evidence for objective measurement of young (0-5 years) children's posture and movement using machine learning and other algorithm methods on accelerometer data. From 1663 papers, a total of 20 papers reporting on 18 studies met the inclusion criteria. Papers were quality-assessed and data extracted and synthesised on sample, postures and movements identified, sensors used, model development, and accuracy. A common limitation of studies was a poor description of their sample data, yet over half scored adequate/good on their overall study design quality assessment. There was great diversity in all aspects examined, with evidence of increasing sophistication in approaches used over time. Model accuracy varied greatly, but for a range of postures and movements, models developed on a reasonable-sized (n > 25) sample were able to achieve an accuracy of >80%. Issues related to model development are discussed and implications for future research outlined. The current evidence suggests the rapidly developing field of machine learning has clear potential to enable the collection of high-quality evidence on the postures and movements of young children.

Physical Activity Dose and Depression in a Cohort of Older Adults in The Irish Longitudinal Study on Ageing.

Importance: Among older adults (aged ≥50 years), depression is associated with an increased risk of physical, social, and cognitive dysfunction. Regular moderate to vigorous physical activity (MVPA) has been associated with lower odds of depression. However, the lowest dose for protection against depression and the extent to which exceeding this level conveys additional protection are unknown. Objective: To evaluate different MVPA doses, depressive symptoms, and major depression status in a large cohort of older adults with and without chronic disease. Design, Setting, and Participants: A longitudinal cohort study of the same 4016 individuals at each of 5 time points (ie, waves) from The Irish Longitudinal Study on Ageing was conducted. Data were collected from October 2009 to December 2018, and data were analyzed from June 15 to August 8, 2022. Exposures: Continuous MVPA (metabolic equivalent of task [MET]-minutes per week [MET-min/wk]), 3 dose categories, and 5 dose categories measured with the International Physical Activity Questionnaire. Main Outcomes and Measures: Depressive symptoms and major depression status were measured using the short form of the Centre for Epidemiological Studies Depression scale along with the Composite International Diagnostic Interview for diagnosis of a major depressive episode during the past 12 months. Multivariable negative random-effects binomial regression models, adjusted for relevant covariates, quantified associations across time. Results: Among the 4016 participants at each wave of the study (2205 women [54.9%]; mean [SD] age, 61.0 [8.1] years) during 10.0 years of follow-up, depression rates increased from a mean of 8.2% (95% CI, 7.4%-9.1%) to 12.2% (95% CI, 11.2%-13.2%). Bonferroni-corrected post hoc analysis indicated that participants performing 400 to less than 600 MET-min/wk had a 16% lower rate of depressive symptoms (adjusted incidence rate ratio [AIRR], 0.84; 95% CI, 0.81-0.86) and 43% lower odds of depression (adjusted odds ratio [AOR], 0.57; 95% CI, 0.49-0.66) compared with 0 MET-min/wk. Those with chronic disease performing 600 to less than 1200 MET-min/wk had an 8% (AIRR, 0.92; 95% CI, 0.86-0.98) lower rate of depressive symptoms and 44% (AOR, 0.56; 95% CI, 0.42-0.74) lower odds of depression compared with 0 MET-min/wk. Those without disease required more than 2400 MET-min/wk for similar protection for depressive symptoms (AIRR, 0.81; 95% CI, 0.73-0.90). Conclusions and relevance: In this cohort study of older adults, significant antidepressant benefits were noted for MVPA doses below current recommendations for overall health, although greater doses were associated with larger AIRR reductions. It may be useful for public health interventions to investigate the achievability of lower physical activity thresholds among older adults with and without chronic illness to reduce the risk of depression.

Physical activity for depression among the chronically Ill: Results from older diabetics in the Irish longitudinal study on ageing.

Among chronically-ill older adults, the benefits of moderate-to-vigorous physical activity (MVPA) are established. Comorbid depressive symptoms and Major Depression are prevalent among the chronically-ill, but how different doses of MVPA may protect against depression remains understudied. Thus, using 10 years of data from The Irish Longitudinal Study on Ageing, we quantified longitudinal associations between MVPA doses and depressive symptoms and Major Depression among chronically-ill older adults living with type 2 diabetes (T2DM). Continuous MVPA (MET.min.week-1), three dose and five dose MVPA categories were examined. Depressive symptoms and Major Depression were measured using the center for Epidemiological Studies Depression and the Composite International Diagnostic Interview for Major Depressive Episode. Negative binomial regression and logistic models, adjusted for covariates, quantified associations across time. Among the 2,262 participants, those adhering to the WHO guidelines of 600-<1,200 MET.min.week-1 had 28% lower odds of Major Depression compared to those not achieving the guidelines (OR: 0.72; 95%CI: 0.53-0.98). For depressive symptoms, a higher MVPA dose was required with a 13% (IRR: 0.87; 95%CI: 0.82-0.93) lower rate of symptoms among those exceeding recommendations (1200-<2,400 MET.min.week-1). Interventions should focus on enhancing achievability of and compliance with these MVPA doses among the chronically-ill, including T2DM, to protect against depression.

Associations of activity, sedentary, and sleep behaviors with cognitive and social-emotional health in early childhood.

Background: Early childhood is important for cognitive and social-emotional development, and a time in which to promote healthy movement behaviors (sedentary behavior, physical activity, and sleep). Movement behaviors may have interactive influences on cognition and social-emotional factors in young children, but most previous research has explored them independently. The purpose of this study was to determine if movement behaviors are associated with measures of cognitive and social-emotional health in young children and if so, to describe optimal compositions of movement behaviors of a daily cycle for such outcomes. Methods: Children (n = 388, 33 to 70 months, 44.6% female) from a clinical trial (ClinicalTrials.gov ID: NCT03285880, first posted September 18, 2017) wore accelerometers on their wrists for 24-h for 9.56 ± 3.3 days. Movement behavior compositions consisted of time spent in sedentary behaviors, light intensity physical activity, moderate to vigorous intensity physical activity (MVPA), and sleep. Outcomes were cognitive (receptive vocabulary, declarative and procedural memory, and executive attention) and social-emotional measures (temperament and behavioral problems). Compositional linear regression models with isometric log ratios were used to investigate the relations between the movement behavior composition and the cognitive and social-emotional health measures. If a significant association was found between the composition and an outcome, we further explored the "optimal" 24-h time-use for said outcome. Results: Movement behavior compositions were associated with receptive vocabulary. The composition associated with the predicted top five percent of vocabulary scores consisted of 12.1 h of sleep, 4.7 h of sedentary time, 5.6 h of light physical activity, and 1.7 h of MVPA. Conclusions: While behavior compositions are related to vocabulary ability in early childhood, our findings align with the inconclusiveness of the current evidence regarding other developmental outcomes. Future research exploring activities within these four movement behaviors, that are meaningful to cognitive and social-emotional development, may be warranted. Supplementary Information: The online version contains supplementary material available at 10.1186/s44167-023-00016-6.

Does occupational forward bending of the back increase long-term sickness absence risk? A 4-year prospective register-based study using device-measured compositional data analysis.

OBJECTIVE: Forward bending of the back is common in many jobs and a risk factor for sickness absence. However, this knowledge is based on self-reported forward bending that is generally imprecise. Thus, we aimed to investigate the dose-response relation between device-measured forward bending at work and prospective register-based risk of long-term sickness absence (LTSA). METHODS: At baseline, 944 workers (93% from blue-collar jobs) wore accelerometers on their upper back and thigh over 1-6 workdays to measure worktime with forward bending (>30˚ and >60˚) and body positions. The first event of LTSA (≥6 consecutive weeks) over a 4-year follow-up were retrieved from a national register. Compositional Cox proportional hazard analyses were used to model the association between worktime with forward bending of the back in an upright body position and LTSA adjusted for age, sex, body mass index (BMI), occupational lifting/carrying, type of work, and, in an additional step, for leisure time physical activity (PA) on workdays. RESULTS: During a mean worktime of 457 minutes/day, the workers on average spent 40 and 10 minutes on forward bending >30˚ and >60˚ in the upright position, respectively. Five more minutes forward bending >30˚ and >60˚ at work were associated with a 4% [95% confidence interval (CI) 1.01-1.07] and 8% (95% CI 1.01-1.16) higher LTSA risk, respectively. Adjustment for leisure-time PA did not influence the results. CONCLUSION: We found a dose-response association between device-measured forward bending of the back and prospective LTSA risk. This knowledge can be integrated into available feasible methods to measure forward bending of the back for improved workplace risk assessment and prevention.

Designing industrial work to be 'just right' to promote health - a study protocol for a goldilocks work intervention.

BACKGROUND: The Goldilocks Work Principle expresses that productive work should be designed to promote workers' health. We recently showed that it is feasible to develop and implement modifications to productive work that change physical behaviors (i.e. sitting, standing and being active) in a direction that may promote health among industrial workers. Therefore, the aim of the present study is to conduct a cluster randomised controlled trial investigating health effects of implementing the Goldilocks Work intervention among industrial workers. METHODS: Our implementation plan consists of educating work teams, organizing implementation meetings, and providing feedback to workers. Three meetings with a preselected local workplace group will be scheduled. The first meeting educates the group to use a planning tool by which work can be planned to have 'just right' physical behaviors. The second and third meetings will focus on supporting implementation of the tool in daily work. An expected 28 clusters of work teams across two participating production sites will be randomized to either intervention or control group. Data collection will consist of 1) questionnaires regarding work and musculoskeletal health, 2) wearable sensor measurements of the physical behavior, and 3) assessment of general health indicators, including BMI, blood pressure, and fat percentage. The primary outcome is musculoskeletal health, measured by low back pain intensity, and secondary outcomes are 1) physical behaviors at work, 2) accumulated time in long bouts of sitting, standing, and being active and 3) perceived fatigue and energy during work. Furthermore, implementation and cost of the intervention will be evaluated based on questionnaires and data from the planning tool completed by the workers. DISCUSSION: This study will evaluate the effectiveness and implementation of a 12 - weeks Goldilocks Work intervention with the aim of improving musculoskeletal health among industrial workers. The cluster randomized controlled study design and the evaluation of the implementation, results and costs of the intervention will make it capable of contributing with valuable evidence of how productive work may be designed to promote industrial workers' health. TRIAL REGISTRATION: Clinical trial registration was assigned 10-09-2021 (ISRCTN80969503). https://doi.org/10.1186/ISRCTN80969503.

Physical Activity Advice for Prevention and Rehabilitation of Low Back Pain- Same or Different? A Study on Device-Measured Physical Activity and Register-Based Sickness Absence.

Purpose We lack knowledge on whether the advice of "being physically active" should be the same for prevention and rehabilitation of low back pain (LBP). Sickness absence is a key outcome for LBP prevention and rehabilitation. We investigated the associations between physical activity and long-term sickness absence (LTSA) among employees with and without LBP. Methods Between 2011 and 2013, 925 Danish employees wore a Actigraph GTX3 accelerometer for 1-5 workdays to measure physical activity and reported LBP in past 7 days. Employees were followed for 4 years to determine their first register-based LTSA event (≥ 6 consecutive weeks). Results Among employees with LBP, increasing moderate-to-vigorous-intensity physical activity at work by 20 min and decreasing the remaining behaviors at work (ie., sitting, standing and light-intensity activity) by 20 min was associated with 38% (95% CI 17%; 63%) higher LTSA risk. Increasing light-intensity activity at work by 20 min and decreasing 20 min from the remaining behaviors was associated with 18% (95% CI 4%; 30%) lower risk. During leisure, increasing moderate-to-vigorous-intensity activity by 20 min or standing by 40 min was associated with 26% (95% CI 3%; 43%) lower and 37% (95% CI 0%; 87%) higher risk, respectively. Among employees without LBP, we found no such associations. Conclusions The physical activity advice ought to be different for LBP prevention and rehabilitation to reduce LTSA risk, and specified by domain and activity intensity. At work, employees with LBP should be advised to spend time on light-intensity physical activity and limit their time on moderate-to-vigorous-intensity physical activity. During leisure, employees should spend time on moderate-to-vigorous-intensity physical activity.

The influence of organizational factors, eldercare worker characteristics and care situation on the use of assistive devices during resident handling in eldercare work.

We evaluated the influence of organization, eldercare worker and care situation on the use of assistive devices during resident handling in eldercare work. We conducted a multi-level study among 20 nursing homes, 126 wards within the nursing homes, 549 eldercare workers within the wards, who performed a total of 1306 care episodes including 3695 resident handlings. The influence of organization (i.e. nursing home and ward), eldercare worker and care situation (i.e. care episode and resident handling) on the use of assistive devices was evaluated using variance components analysis and multivariate generalized linear mixed model. Nursing homes, wards, eldercare workers, care episodes and 'within care episode' all contributed to the total variance in use of assistive devices. Organizational factors and care situation factors were significantly associated with use of assistive devices. All levels of the nursing homes, but in particular care situation, influence the use of assistive devices during resident handling.

How does accelerometry-measured arm elevation at work influence prospective risk of long-term sickness absence?

OBJECTIVE: Elevated arm work is prevalent in many jobs. Feasible device-based methods are available to measure elevated arm work. However, we lack knowledge on the association between device-measured elevated arm work and prospective risk of long-term sickness absence (LTSA). We aimed to investigate this association. METHODS: At baseline, 937 workers wore accelerometers on the right arm and thigh over 1-5 workdays to measure work time spent with elevated arms in an upright position. Between baseline and 4-year prospective follow-up in the national registers, we obtained information on the individuals` first event of LTSA (≥6 consecutive weeks). We performed compositional Cox proportional hazard analyses to model the association between work time with arm elevation >30˚, >60˚, or >90˚ and the probability of LTSA. RESULTS: Workers spent 21% of their work time with >30˚ arm elevation, 4% with >60˚ arm elevation, and 1% with >90˚ arm elevation; in the upright body position. We found a positive dose-response association between work time spent with elevated arm work and the risk of LTSA. Specifically, we found that increasing two minutes of work time spent with arm elevation at (i) >90˚ increased the risk of LTSA by 14% [hazard ratio (HR) 1.14, 95% confidence intervals (95% CI 1.04-1.25)] (ii) >60˚ increased the LTSA risk by 3% (HR 1.03, 95% CI 1.03-1.06), and (iii) >30˚ increased the LTSA risk by 1% (HR 1.01, 95% CI 1.00-1.02). CONCLUSION: Device-measured elevated arm work is associated with increased prospective LTSA. This information ought to be brought into preventive workplace practice by accessible and feasible device-based methods of elevated arm work.

24-Hour Physical Behavior Balance for Better Health for All: "The Sweet-Spot Hypothesis".

"Sit less-move more" has been the univocal advice to adults for better health. Predominantly, this advice is based on research of physical behaviors during leisure-time. A recent study among > 100,000 adults indicates a u-shaped association between leisure-time physical activity and risk for cardiovascular disease and mortality among adults in physically active occupations. This may be explained by the considerable difference in 24-h physical behaviors between adults in sedentary and physically active occupations. Thus, the advice "sit less-move more" might not be the best for health among adults in physically active occupations. To provide a scientific approach and encourage research on 24-h physical behaviors and health for those in physically active occupations, we propose the "Sweet-Spot Hypothesis." The hypothesis postulates that the "Sweet-Spot" of 24-h physical behaviors for better health differs between adults, depending on their occupation. Specifically, the hypothesis claims that the advice "sit less-move more" does not bring adults in physically active occupations toward their "Sweet-Spot" of 24-h physical behaviors for better health. The purpose of our paper is to encourage researchers to test this proposed hypothesis by describing its origin, its theoretical underpinning, approaches to test it, and practical implications. To promote health for all, and decrease social health inequalities, we see a great need for empirically testing the "Sweet-Spot Hypothesis." We propose the "Sweet-Spot Hypothesis" to encourage discussion, debates, and empirical research to expand our collective knowledge about the healthy "24-h physical behavior balance" for all.

Does Childcare Work Promote Cardiorespiratory Fitness and Health? A Cross-Sectional Study of Danish Childcare Workers Based on Accelerometry and Heart Rate Measurements.

Childcare workers are reported to have poor cardiorespiratory fitness and health. The Goldilocks Work Principle argues that productive work should be designed with the right composition, intensity and alternations of physical behaviors so that workers get fit and healthy. The purpose of this study was to investigate: (1) composition, (2) intensity and (3) alternations of physical behaviors during work and leisure among childcare workers. Data were collected using accelerometers and heart rate monitors over five workdays among 51 childcare workers at five Danish childcare institutions. Workers mainly spent their work time sedentary (43.0%), spent little time (0.7%) at sufficiently high cardiometabolic intensity to increase cardiorespiratory fitness and often alternated between physical behaviors (67.0% occurred in bouts of <5 min). These findings indicate that the workers have a composition of behaviors at work dominated by sedentary time, little time with high cardiometabolic intensity, and frequent alternations between behaviors. During leisure, workers spent more time sedentary (59.4%), more time at high cardiometabolic intensity (3.4%) and less time occurred in bouts <5 min (38.7%). We see a potential for promoting cardiorespiratory fitness and health of childcare workers by redesigning the way they play with the children, so that work time with high cardiometabolic intensity is increased.

Day-to-day pattern of work and leisure time physical behaviours: are low socioeconomic status adults couch potatoes or work warriors?

BACKGROUND: Most studies on day-to-day patterns of physical behaviours (i.e. physical activities and sedentary behaviour) are based on adults with high socioeconomic status (SES) and without differentiating between work and leisure time. Thus, we aimed to characterise the day-to-day leisure time physical behaviours patterns among low SES adults and investigate the influence of work physical behaviours. METHODS: This cross-sectional study included 963 adults from low SES occupations (e.g. manufacturing, cleaning and transportation). The participants wore accelerometers for 1-7 days to measure physical behaviours during work and leisure time, expressed as time-use compositions consisting of time spent sedentary, standing or being active (walking, running, stair climbing, or cycling). Compositional multivariate multilevel models were used to regress daily leisure time-use composition against work time-use compositions. Interaction between weekday and (1) type of day, (i.e., work/non-work) and (2) the work time-use composition were tested. Compositional isotemporal substitution was used to interpret the estimates from the models. RESULTS: Each weekday, workers consistently spent most leisure time being sedentary and most work time standing. Leisure time physical behaviours were associated with type of day (p < 0.005, more sedentary on workdays vs. non-workdays), weekday (p < 0.005, more sedentary on Friday, Saturday and Sunday), standing work (p < 0.005, more sedentary and less standing and active leisure time on Sunday), and active work (p < 0.005, less sedentary and more standing and active leisure time on Sunday). Sedentary leisure time increased by 18 min, while standing and active leisure time decreased by 11 and 7 min, respectively, when 30 min were reallocated to standing at work on Sunday. Conversely, sedentary leisure time decreased by 25 min, and standing and active leisure time increased by 15 and 10 min, respectively, when 30 min were reallocated to active time at work on Sunday. CONCLUSIONS: While low SES adults' leisure time was mostly sedentary, their work time was predominantly standing. Work physical behaviours differently influenced day-to-day leisure time behaviours. Thus, public health initiatives aiming to change leisure time behaviours among low SES adults should consider the influence of work physical behaviours.

The effect of leisure time physical activity and sedentary behaviour on the health of workers with different occupational physical activity demands: a systematic review.

BACKGROUND: Although it is generally accepted that physical activity reduces the risk for chronic non-communicable disease and mortality, accumulating evidence suggests that occupational physical activity (OPA) may not confer the same health benefits as leisure time physical activity (LTPA). It is also unclear if workers in high OPA jobs benefit from LTPA the same way as those in sedentary jobs. Our objective was to determine whether LTPA and leisure time sedentary behaviour (LTSB) confer the same health effects across occupations with different levels of OPA. METHODS: Searches were run in Medline, Embase, PsycINFO, ProQuest Public Health and Scopus from inception to June 9, 2020. Prospective or experimental studies which examined the effects of LTPA or LTSB on all-cause and cardiovascular mortality and cardiovascular disease, musculoskeletal pain, diabetes, metabolic syndrome, arrhythmias and depression among adult workers grouped by OPA (low OPA/sitters, standers, moderate OPA/intermittent movers, high OPA/heavy labourers) were eligible. Results were synthesized using narrative syntheses and harvest plots, and certainty of evidence assessed with GRADE. RESULTS: The review includes 38 papers. Across all outcomes, except cardiovascular mortality, metabolic syndrome and atrial fibrillation, greater LTPA was consistently protective among low OPA, but conferred less protection among moderate and high OPA. For cardiovascular mortality and metabolic syndrome, higher levels of LTPA were generally associated with similar risk reductions among all OPA groups. Few studies examined effects in standers and none examined effects of LTSB across OPA groups. CONCLUSIONS: Evidence suggests that LTPA is beneficial for all workers, but with larger risk reductions among those with low compared to high OPA jobs. This suggests that, in our attempts to improve the health of workers through LTPA, tailored interventions for different occupational groups may be required. More high-quality studies are needed to establish recommended levels of LTPA/LTSB for different OPA groups. PROTOCOL REGISTRATION: PROSPERO # CRD42020191708 .

Development and Implementation of 'Just Right' Physical Behavior in Industrial Work Based on the Goldilocks Work Principle-A Feasibility Study.

The Goldilocks Work Principle expresses that productive work should be redesigned to comprise physical behaviors of different intensities in a composition promoting workers' health and fitness. This study is the first to assess the feasibility of redesigning work in an industrial setting according to the Goldilocks Work Principle. We recruited workers (n = 20) from a brewery in Denmark, and we conducted a participatory 16-week intervention including a workshop and two consultations. The workshop aimed to support the workers in modifying their work, while the consultations assisted the eventual implementation. Feasibility was evaluated as per three aspects: (1) developing modifications of work, (2) implementing these modifications, and (3) changing physical behavior and self-reported fatigue, pain and energy. The three aspects were addressed through records completed by the workers, measurements of workers' physical behavior and intensity during 'control' workdays (i.e., usual work) and 'intervention' workdays (i.e., modified work), and self-reported fatigue, pain and energy level following both types of workday. Five modifications to work were developed, and three of these five modifications were implemented. To some extent, physical behavior and intensity changed as intended during 'intervention' workdays compared to 'control' workdays. Workers were also less fatigued, had less pain, and had more energy after 'intervention' workdays. These results suggest that it is feasible to develop and implement modified work based on the Goldilocks Work Principle among industrial workers. However, we also identified several barriers to the implementation of such modifications.

The Relation between Domain-Specific Physical Behaviour and Cardiorespiratory Fitness: A Cross-Sectional Compositional Data Analysis on the Physical Activity Health Paradox Using Accelerometer-Assessed Data.

In contrast to leisure time physical activity (LTPA), occupational physical activity (OPA) does not have similar beneficial health effects. These differential health effects might be explained by dissimilar effects of LTPA and OPA on cardiorespiratory fitness (CRF). This study investigated cross-sectional associations between different physical behaviours during both work and leisure time and CRF by using a Compositional Data Analysis approach. Physical behaviours were assessed by two accelerometers among 309 workers with various manual jobs. During work time, more sedentary behaviour (SB) was associated with higher CRF when compared relatively to time spent on other work behaviours, while more SB during leisure time was associated with lower CRF when compared to other leisure time behaviours. Reallocating more time to moderate-to-vigorous physical activity (MVPA) from the other behaviours within leisure time was positively associated with CRF, which was not the case for MVPA during work. The results of our study are in line with the physical activity health paradox and we call for further study on the interaction between LTPA and OPA by implementing device-worn measures in a longitudinal design. Our results highlight the need for recommendations to take into account the different effects of OPA and LTPA on CRF.

Zero problems with compositional data of physical behaviors: a comparison of three zero replacement methods.

BACKGROUND: Researchers applying compositional data analysis to time-use data (e.g., time spent in physical behaviors) often face the problem of zeros, that is, recordings of zero time spent in any of the studied behaviors. Zeros hinder the application of compositional data analysis because the analysis is based on log-ratios. One way to overcome this challenge is to replace the zeros with sensible small values. The aim of this study was to compare the performance of three existing replacement methods used within physical behavior time-use epidemiology: simple replacement, multiplicative replacement, and log-ratio expectation-maximization (lrEM) algorithm. Moreover, we assessed the consequence of choosing replacement values higher than the lowest observed value for a given behavior. METHOD: Using a complete dataset based on accelerometer data from 1310 Danish adults as reference, multiple datasets were simulated across six scenarios of zeros (5-30% zeros in 5% increments). Moreover, four examples were produced based on real data, in which, 10 and 20% zeros were imposed and replaced using a replacement value of 0.5 min, 65% of the observation threshold, or an estimated value below the observation threshold. For the simulation study and the examples, the zeros were replaced using the three replacement methods and the degree of distortion introduced was assessed by comparison with the complete dataset. RESULTS: The lrEM method outperformed the other replacement methods as it had the smallest influence on the structure of relative variation of the datasets. Both the simple and multiplicative replacements introduced higher distortion, particularly in scenarios with more than 10% zeros; although the latter, like the lrEM, does preserve the ratios between behaviors with no zeros. The examples revealed that replacing zeros with a value higher than the observation threshold severely affected the structure of relative variation. CONCLUSIONS: Given our findings, we encourage the use of replacement methods that preserve the relative structure of physical behavior data, as achieved by the multiplicative and lrEM replacements, and to avoid simple replacement. Moreover, we do not recommend replacing zeros with values higher than the lowest observed value for a behavior.