Device-measured physical activity and cardiometabolic health: the Prospective Physical Activity, Sitting, and Sleep (ProPASS) consortium.

BACKGROUND AND AIMS: Physical inactivity, sedentary behaviour (SB), and inadequate sleep are key behavioural risk factors of cardiometabolic diseases. Each behaviour is mainly considered in isolation, despite clear behavioural and biological interdependencies. The aim of this study was to investigate associations of five-part movement compositions with adiposity and cardiometabolic biomarkers. METHODS: Cross-sectional data from six studies (n = 15 253 participants; five countries) from the Prospective Physical Activity, Sitting and Sleep consortium were analysed. Device-measured time spent in sleep, SB, standing, light-intensity physical activity (LIPA), and moderate-vigorous physical activity (MVPA) made up the composition. Outcomes included body mass index (BMI), waist circumference, HDL cholesterol, total:HDL cholesterol ratio, triglycerides, and glycated haemoglobin (HbA1c). Compositional linear regression examined associations between compositions and outcomes, including modelling time reallocation between behaviours. RESULTS: The average daily composition of the sample (age: 53.7 ± 9.7 years; 54.7% female) was 7.7 h sleeping, 10.4 h sedentary, 3.1 h standing, 1.5 h LIPA, and 1.3 h MVPA. A greater MVPA proportion and smaller SB proportion were associated with better outcomes. Reallocating time from SB, standing, LIPA, or sleep into MVPA resulted in better scores across all outcomes. For example, replacing 30 min of SB, sleep, standing, or LIPA with MVPA was associated with -0.63 (95% confidence interval -0.48, -0.79), -0.43 (-0.25, -0.59), -0.40 (-0.25, -0.56), and -0.15 (0.05, -0.34) kg/m2 lower BMI, respectively. Greater relative standing time was beneficial, whereas sleep had a detrimental association when replacing LIPA/MVPA and positive association when replacing SB. The minimal displacement of any behaviour into MVPA for improved cardiometabolic health ranged from 3.8 (HbA1c) to 12.7 (triglycerides) min/day. CONCLUSIONS: Compositional data analyses revealed a distinct hierarchy of behaviours. Moderate-vigorous physical activity demonstrated the strongest, most time-efficient protective associations with cardiometabolic outcomes. Theoretical benefits from reallocating SB into sleep, standing, or LIPA required substantial changes in daily activity.

Post-diagnosis adiposity, physical activity, sedentary behaviour, dietary factors, supplement use and colorectal cancer prognosis: Global Cancer Update Programme (CUP Global) summary of evidence grading.

Based on the World Cancer Research Fund Global Cancer Update Programme, we performed systematic reviews and meta-analyses to investigate the association of post-diagnosis adiposity, physical activity, sedentary behaviour, and dietary factors with colorectal cancer prognosis. We searched PubMed and Embase until 28th February, 2022. An independent expert committee and expert panel graded the quality of evidence. A total of 167 unique publications were reviewed, and all but five were observational studies. The quality of the evidence was graded conservatively due to the high risk of several biases. There was evidence of non-linearity in the associations between body mass index and colorectal cancer prognosis. The associations appeared reverse J-shaped, and the quality of this evidence was graded as limited (likelihood of causality: limited-no conclusion). The evidence on recreational physical activity and lower risk of all-cause mortality (relative risk [RR] highest vs. lowest: 0.69, 95% confidence interval [CI]: 0.62-0.77) and recurrence/disease-free survival (RR: 0.80, 95% CI: 0.70-0.92) was graded as limited-suggestive. There was limited-suggestive evidence for the associations between healthy dietary and/or lifestyle patterns (including diets that comprised plant-based foods), intake of whole grains and coffee with lower risk of all-cause mortality, and between unhealthy dietary patterns and intake of sugary drinks with higher risk of all-cause mortality. The evidence for other exposures on colorectal cancer outcomes was sparse and graded as limited-no conclusion. Analyses were conducted excluding cancer patients with metastases without substantial changes in the findings. Well-designed intervention and cohort studies are needed to support the development of lifestyle recommendations for colorectal cancer patients.

How strong is the evidence supporting the WHO guidelines on physical activity, sedentary behaviour and sleep in early childhood?

BACKGROUND: The WHO issued recommendations about the ideal amount of physical activity, sedentary behaviour and sleep in infants, toddlers and preschool children. To facilitate their interpretation and translation into public health policies, we analysed the quantity and quality of the evidence that supported the development of each WHO recommendation. METHODS: All data for each exposure-outcome pair analysed in the studies informing WHO guidelines were extracted, and predefined criteria, based upon GRADE methodology, were used to classify each outcome and study result. RESULTS: Among the 237 studies that could be included, 37 were experimental and 200 were observational, yielding 920 analyses of exposure-outcome associations. Sixty-two analyses used a relevant outcome, with or without significant results. Five of the 10 WHO recommendations were based upon zero analyses with significant results on relevant health outcomes. The remaining recommendations were mostly based upon analyses evaluating obesity-related outcomes. Eight of the 10 GLs thresholds were not supported by any significant analysis on clinically relevant outcomes. CONCLUSION: While these findings should not be interpreted as an attempt to disprove the benefits of healthy lifestyle habits in early childhood, neither to minimize the work of the experts in this complex research field, very limited evidence currently supports the adoption of recommended thresholds as behavioural surveillance and public health interventions targets. Therefore, until further data are available, public health interventions should be developed balancing whether to focus on the achievement of specific targets that are still not supported by high-quality evidence or on the general promotion of healthy behaviours.

Resistance exercise breaks during prolonged sitting augment the blood flow response to a subsequent oral glucose load in sedentary adults.

Sitting-induced impairments in postprandial blood flow are an important link between sedentary behaviour and cardiometabolic disease risk. The objective of this work was to examine the effects of resistance exercise breaks (REB) performed every 30 min during an otherwise sedentary 3-h period on the vasodilatory response to a subsequent oral glucose load in sedentary adults. Twenty-four sedentary adults (27 ± 7 years, 16 females) completed two conditions. Fasting blood glucose, insulin, popliteal artery blood flow (PABF) and gastrocnemius perfusion were measured immediately before standardized breakfast consumption. After breakfast, the 3-h REB or uninterrupted (SIT) intervention period commenced. Participants sat at a workstation, and popliteal artery shear rate (PASR) was measured 60 and 120 min into this period. In the REB condition, participants performed a 3-min REB (3 × [20 s squats, 20 s high knees, 20 s calf raises]) every 30 min. Following the intervention period, baseline measurements were repeated. Participants then consumed a 75 g glucose beverage, and PABF and perfusion were measured every 30-60 min for the following 120 min. Relative to SIT, REB increased PASR at 60 min (+31.4 ± 9.2/s, P = 0.037) and 120 min (+37.4 ± 10.2/s, P = 0.019) into the intervention period. Insulin and glucose increased (P < 0.001) in response to glucose consumption, with no differences between conditions (P ≥ 0.299). In response to the glucose load, perfusion (1.57 vs. 1.11 mL/100 mL/min, P = 0.023) and PABF (+45.3 ± 11.8 mL/min, P = 0.001) were greater after REB versus SIT. Performing 3-min REB every 30 min during an otherwise sedentary 3-h period augmented leg blood flow responses to an oral glucose load. HIGHLIGHTS: What is the central question of this study? Can 3-min resistance exercise breaks (REB) performed during an otherwise sedentary 3-h period augment the vasodilatory response to a subsequent oral glucose load in sedentary adults? What is the main finding and its importance? Performing 3-min REB, which included squats, high knees, and calf raises, every 30 min augmented lower limb blood flow responses to a subsequent oral glucose load compared to 3 h of uninterrupted sitting in sedentary adults. Sitting-induced impairment in postprandial vasodilatory function has been identified as a link between sedentary behaviour and cardiometabolic disease. Thus, the current study presents a potentially effective strategy to offset this risk.

Effects of light-intensity physical activity on cardiometabolic parameters in young adults with overweight and obesity: The SED-ACT randomized controlled crossover trial.

AIMS: To investigate how a change in body position with light-intensity physical activity (PA) 'snacks' (LIPAS, alternate sitting and standing, walking or standing continuously) compared with uninterrupted prolonged sitting affects glucose metabolism and heart rate variability (HRV) parameters in young adults with overweight and obesity. MATERIALS AND METHODS: We conducted a four-arm randomized controlled crossover trial. The following conditions were tested during an 8-h simulated workday: uninterrupted prolonged sitting (SIT), alternate sitting and standing (SIT-STAND; 2.5 h total), continuous standing (STAND), and continuous walking (1.0 mph; WALK). The primary outcome was to investigate how a change in body position (alternate sitting and standing, walking or standing continuously) compared with uninterrupted sitting affects mean 8-h glucose metabolism. Secondary outcomes included the effects on 2-h postprandial glucose concentrations, as well as on 8-h/24-h heart rate and HRV parameters, in the respective study arms. Capillary blood samples were drawn from an hyperemised earlobe in the fasted state and once every hour during each trial intervention by puncturing the earlobe with a lancet and collecting 20 µL of blood (Biosen S-Line Lab+; EKF diagnostics, Barleben, Germany). HRV was assessed for 24 h including the 8-h intervention phase, and a home phase by means of a Holter electrocardiogram. All participants received the same standardized non-relativised breakfast and lunch during the four trial visits. RESULTS: Seventeen individuals (eight women, mean age 23.4 ± 3.3 years, body mass index 29.7 ± 3.8 kg/m2, glycated haemoglobin level 34.8 ± 3.1 mmol/mol [5.4 ± 0.3%], body fat 31.8 ± 8.2%) completed all four trial arms. Compared with SIT (89.4 ± 6.8 mg/dL), 8-h mean glucose was lower in all other conditions (p < 0.05) and this was statistically significant compared with WALK (86.3 ± 5.2 mg/dL; p = 0.034). Two-hour postprandial glucose after breakfast was approximately 7% lower for WALK compared with SIT (p = 0.002). Furthermore, significant time × condition effects on HRV parameters favouring light-intensity walking were observed (p < 0.001). CONCLUSIONS: Replacement and interruption of prolonged sitting with light-intensity walking showed a significant blood glucose-lowering effect and improved HRV during an 8-h work environment in young adults with overweight and obesity.

Effectiveness of workplace interventions with digital elements to reduce sedentary behaviours in office employees: a systematic review and meta-analysis.

BACKGROUND: Digital interventions are potential tools for reducing and limiting occupational sedentary behaviour (SB) in sedentary desk-based jobs. Given the harmful effects of sitting too much and sitting for too long while working, the aim of this systematic review and meta-analysis was to examine the effectiveness of workplace interventions, that incorporated digital elements, to reduce the time spent in SB in office workers. METHODS: Randomised control trials that evaluated the implementation of workplace interventions that incorporated digital elements for breaking and limiting SB among desk-based jobs were identified by literature searches in six electronic databases (PubMed, Web of Science, Scopus, CINAHL, PsycINFO and PEDro) published up to 2023. Studies were included if total and/or occupational SB were assessed. Only studies that reported pre- and postintervention mean differences and standard deviations or standard errors for both intervention arms were used for the meta-analysis. The meta-analysis was conducted using Review Manager 5 (RevMan 5; Cochrane Collaboration, Oxford, UK). Risk of bias was assessed using the Standard Quality Assessment Criteria for Evaluating Primary Research Papers from a Variety of Fields QUALSYST tool. RESULTS: Nineteen studies were included in the systematic review. The most employed digital elements were information delivery and mediated organisational support and social influences. Multicomponent, information, and counselling interventions measuring total and/or occupational/nonoccupational SB time by self-report or via device-based measures were reported. Multicomponent interventions were the most represented. Eleven studies were included in the meta-analysis, which presented a reduction of 29.9 (95% CI: -45.2, -14.5) min/8 h workday in SB (overall effect: Z = 3.81). CONCLUSIONS: Multicomponent interventions, using a wide range of digital features, have demonstrated effectiveness in reducing time spent in SB at the workplace among desk-based employees. However, due to hybrid work (i.e., work in the office and home) being a customary mode of work for many employees, it is important for future studies to assess the feasibility and effectiveness of these interventions in the evolving work landscape. TRIAL REGISTRATION: The review protocol was registered in the Prospero database (CRD42022377366).

Comparing national device-based physical activity surveillance systems: a systematic review.

BACKGROUND: Physical activity surveillance systems are important for public health monitoring but rely mostly on self-report measurement of physical activity. Integration of device-based measurements in such systems can improve population estimates, however this is still relatively uncommon in existing surveillance systems. This systematic review aims to create an overview of the methodology used in existing device-based national PA surveillance systems. METHODS: Four literature databases (PubMed, Embase.com, SPORTDiscus and Web of Science) were searched, supplemented with backward tracking. Articles were included if they reported on population-based (inter)national surveillance systems measuring PA, sedentary time and/or adherence to PA guidelines. When available and in English, the methodological reports of the identified surveillance studies were also included for data extraction. RESULTS: This systematic literature search followed the PRISMA guidelines and yielded 34 articles and an additional 18 methodological reports, reporting on 28 studies, which in turn reported on one or multiple waves of 15 different national and 1 international surveillance system. The included studies showed substantial variation between (waves of) systems in number of participants, response rates, population representativeness and recruitment. In contrast, the methods were similar on data reduction definitions (e.g. minimal number of valid days, non-wear time and necessary wear time for a valid day). CONCLUSIONS: The results of this review indicate that few countries use device-based PA measurement in their surveillance system. The employed methodology is diverse, which hampers comparability between countries and calls for more standardized methods as well as standardized reporting on these methods. The results from this review can help inform the integration of device-based PA measurement in (inter)national surveillance systems.

The Wearable Activity Tracker Checklist for Healthcare (WATCH): a 12-point guide for the implementation of wearable activity trackers in healthcare.

Increasing physical activity in patients offers dual benefits, fostering improved patient health and recovery, while also bolstering healthcare system efficiency by minimizing costs related to extended hospital stays, complications, and readmissions. Wearable activity trackers offer valuable opportunities to enhance physical activity across various healthcare settings and among different patient groups. However, their integration into healthcare faces multiple implementation challenges related to the devices themselves, patients, clinicians, and systemic factors. This article presents the Wearable Activity Tracker Checklist for Healthcare (WATCH), which was recently developed through an international Delphi study. The WATCH provides a comprehensive framework for implementation and evaluation of wearable activity trackers in healthcare. It covers the purpose and setting for usage; patient, provider, and support personnel roles; selection of relevant metrics; device specifications; procedural steps for issuance and maintenance; data management; timelines; necessary adaptations for specific scenarios; and essential resources (such as education and training) for effective implementation. The WATCH is designed to support the implementation of wearable activity trackers across a wide range of healthcare populations and settings, and in those with varied levels of experience. The overarching goal is to support broader, sustained, and systematic use of wearable activity trackers in healthcare, therefore fostering enhanced physical activity promotion and improved patient outcomes.

Thigh-worn accelerometry: a comparative study of two no-code classification methods for identifying physical activity types.

BACKGROUND: The more accurate we can assess human physical behaviour in free-living conditions the better we can understand its relationship with health and wellbeing. Thigh-worn accelerometry can be used to identify basic activity types as well as different postures with high accuracy. User-friendly software without the need for specialized programming may support the adoption of this method. This study aims to evaluate the classification accuracy of two novel no-code classification methods, namely SENS motion and ActiPASS. METHODS: A sample of 38 healthy adults (30.8 ± 9.6 years; 53% female) wore the SENS motion accelerometer (12.5 Hz; ±4 g) on their thigh during various physical activities. Participants completed standardized activities with varying intensities in the laboratory. Activities included walking, running, cycling, sitting, standing, and lying down. Subsequently, participants performed unrestricted free-living activities outside of the laboratory while being video-recorded with a chest-mounted camera. Videos were annotated using a predefined labelling scheme and annotations served as a reference for the free-living condition. Classification output from the SENS motion software and ActiPASS software was compared to reference labels. RESULTS: A total of 63.6 h of activity data were analysed. We observed a high level of agreement between the two classification algorithms and their respective references in both conditions. In the free-living condition, Cohen's kappa coefficients were 0.86 for SENS and 0.92 for ActiPASS. The mean balanced accuracy ranged from 0.81 (cycling) to 0.99 (running) for SENS and from 0.92 (walking) to 0.99 (sedentary) for ActiPASS across all activity types. CONCLUSIONS: The study shows that two available no-code classification methods can be used to accurately identify basic physical activity types and postures. Our results highlight the accuracy of both methods based on relatively low sampling frequency data. The classification methods showed differences in performance, with lower sensitivity observed in free-living cycling (SENS) and slow treadmill walking (ActiPASS). Both methods use different sets of activity classes with varying definitions, which may explain the observed differences. Our results support the use of the SENS motion system and both no-code classification methods.

Device-measured sedentary time and intensity-specific physical activity in relation to all-cause and cardiovascular disease mortality: the UK Biobank cohort study.

BACKGROUND AND AIMS: Understanding the amounts of intensity-specific movement needed to attenuate the association between sedentary time and mortality may help to inform personalized prescription and behavioral counselling. Herein, we examined the joint associations of sedentary time and intensity-specific physical activity with all-cause and cardiovascular disease (CVD) mortality. METHODS: Prospective cohort study including 73,729 adults from the UK Biobank who wore an Axivity AX3 accelerometer on their dominant wrist for at least 3 days, being one a weekend day, between June 2013 and December 2015. We considered the median tertile values of sedentary time and physical activity in each intensity band to determine the amount of physical activity needed to attenuate the association between sedentary time and mortality. RESULTS: During a median of 6.9 years of follow-up (628,807 person-years), we documented 1521 deaths, including 388 from CVD. Physical activity of any intensity attenuated the detrimental association of sedentary time with mortality. Overall, at least a median of 6 min/day of vigorous physical activity, 30 min/day of MVPA, 64 min/day of moderate physical activity, or 163 min/day of light physical activity (mutually-adjusted for other intensities) attenuated the association between sedentary time and mortality. High sedentary time was associated with higher risk of CVD mortality only among participants with low MVPA (HR 1.96; 95% CI 1.23 to 3.14). CONCLUSIONS: Different amounts of each physical activity intensity may attenuate the association between high sedentary time and mortality.

The cross-sectional and prospective associations of parental practices and environmental factors with 24-hour movement behaviours among school-aged Asian children.

BACKGROUND: Parental practices and neighbourhood environmental factors may influence children's movement behaviours. We aimed to investigate the cross-sectional and prospective associations of parental practices and neighbourhood environmental factors with accelerometer-measured 24-hour movement behaviours (24 h-MBs) among school-aged children in Singapore. METHODS: The Growing Up in Singapore Towards healthy Outcomes (GUSTO) study collected information on dimensions of parental practices and neighbourhood environment at age 5.5 years. Confirmatory factor analyses were performed to generate latent variables and used to compute overall parental practices [involvement in PA + support for PA + control of screen viewing context] and environmental scores [facilities for active play + active mobility facilitators + barriers*-1]. Children wore an accelerometer on their non-dominant wrist for seven consecutive days at ages 5.5 and 8 years. The R-package GGIR 2.6 was used to derive moderate-to-vigorous-intensity physical activity (MVPA), light-intensity physical activity (LPA), inactivity, and total-sleep (napping+night sleep) minutes per day. Associations were determined using compositional data analysis with multivariate linear regression models, taking into account potential confounders. RESULTS: Among 425 children (48% girls, 59% Chinese), higher parental involvement in PA, parental support for PA and overall parental practices were associated with 24 h-MBs at ages 5.5 and 8 years, specifically with greater time spent in MVPA and less time being inactive relative to the remaining movement behaviours. The corresponding mean changes in the overall 24 h-MB for increasing parental practices from lowest to highest scores (- 2 to + 2 z-scores) indicated potential increases of up to 15-minutes in MVPA, 20-minutes in LPA, 5-minutes in sleep duration, and a reduction of 40-minutes in inactivity at age 5.5 years. At age 8 years, this could translate to approximately 15-minutes more of MVPA, 20-minutes more of LPA, a 20-minute reduction in sleep duration, and a 20-minute reduction in inactivity. Parental control of screen viewing contexts and neighbourhood environmental factors were not associated with 24 h-MBs. CONCLUSIONS: Parental practices but not environmental factors were associated with higher MVPA and lower inactivity among Singaporean children, even at a later age. Further research may provide insights that support development of targeted public health strategies to promote healthier movement behaviours among children. STUDY REGISTRATION: This study was registered on 4th August 2010 and is available online at ClinicalTrials.gov: NCT01174875.

Cross-sectional associations between 24-hour time-use composition, grey matter volume and cognitive function in healthy older adults.

BACKGROUND: Increasing physical activity (PA) is an effective strategy to slow reductions in cortical volume and maintain cognitive function in older adulthood. However, PA does not exist in isolation, but coexists with sleep and sedentary behaviour to make up the 24-hour day. We investigated how the balance of all three behaviours (24-hour time-use composition) is associated with grey matter volume in healthy older adults, and whether grey matter volume influences the relationship between 24-hour time-use composition and cognitive function. METHODS: This cross-sectional study included 378 older adults (65.6 ± 3.0 years old, 123 male) from the ACTIVate study across two Australian sites (Adelaide and Newcastle). Time-use composition was captured using 7-day accelerometry, and T1-weighted magnetic resonance imaging was used to measure grey matter volume both globally and across regions of interest (ROI: frontal lobe, temporal lobe, hippocampi, and lateral ventricles). Pairwise correlations were used to explore univariate associations between time-use variables, grey matter volumes and cognitive outcomes. Compositional data analysis linear regression models were used to quantify associations between ROI volumes and time-use composition, and explore potential associations between the interaction between ROI volumes and time-use composition with cognitive outcomes. RESULTS: After adjusting for covariates (age, sex, education), there were no significant associations between time-use composition and any volumetric outcomes. There were significant interactions between time-use composition and frontal lobe volume for long-term memory (p = 0.018) and executive function (p = 0.018), and between time-use composition and total grey matter volume for executive function (p = 0.028). Spending more time in moderate-vigorous PA was associated with better long-term memory scores, but only for those with smaller frontal lobe volume (below the sample mean). Conversely, spending more time in sleep and less time in sedentary behaviour was associated with better executive function in those with smaller total grey matter volume. CONCLUSIONS: Although 24-hour time use was not associated with total or regional grey matter independently, total grey matter and frontal lobe grey matter volume moderated the relationship between time-use composition and several cognitive outcomes. Future studies should investigate these relationships longitudinally to assess whether changes in time-use composition correspond to changes in grey matter volume and cognition.

Validity and reliability of self-reported methods for assessment of 24-h movement behaviours: a systematic review.

BACKGROUND: Time spent in sleep, sedentary behaviour (SB), and physical activity are exhaustive and mutually exclusive parts of a 24-h day that need to be considered in a combination. The aim of this study was to identify validated self-reported tools for assessment of movement behaviours across the whole 24-h day, and to review their attributes and measurement properties. METHODS: The databases PubMed, Scopus, and SPORTDiscus were searched until September 2023. Inclusion criteria were: (i) published in English language, (ii) per-reviewed paper, (iii) assessment of self-reported time spent in sleep, SB, and physical activity, (iv) evaluation of measurement properties of all estimates across the full 24-h day, and (v) inclusion of adolescents, adults, or older adults. The methodological quality of included studies was assessed using the Consensus-based Standards for the selection of health Measurement Instruments checklist. RESULTS: Our search returned 2064 records. After studies selection, we included 16 articles that reported construct validity and/or test-retest reliability of 12 unique self-reported tools - eight questionnaires, three time-use recalls, and one time-use diary. Most tools enable assessment of time spent in sleep, and domain-specific SB and physical activity, and account that sum of behaviours should be 24 h. Validity (and reliability) correlation coefficients for sleep ranged between 0.22 and 0.69 (0.41 and 0.92), for SB between 0.06 and 0.57 (0.33 and 0.91), for light-intensity physical activity between 0.18 and 0.46 (0.55 and 0.94), and for moderate- to vigorous-intensity physical activity between 0.38 and 0.56 (0.59 and 0.94). The quality of included studies being mostly fair-to-good. CONCLUSIONS: This review found that only a limited number of validated self-reported tools for assessment of 24-h movement behaviours are currently available. Validity and reliability of most tools are generally adequate to be used in epidemiological studies and population surveillance, while little is known about adequacy for individual level assessments and responsiveness to behavioural change. To further support research, policy, and practice, there is a need to develop new tools that resonate with the emerging 24-h movement paradigm and to evaluate measurement properties by using compositional data analysis. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42022330868.

The impact of the world's first regulatory, multi-setting intervention on sedentary behaviour among children and adolescents (ENERGISE): a natural experiment evaluation.

BACKGROUND: Regulatory actions are increasingly used to tackle issues such as excessive alcohol or sugar intake, but such actions to reduce sedentary behaviour remain scarce. World Health Organization (WHO) guidelines on sedentary behaviour call for system-wide policies. The Chinese government introduced the world's first nation-wide multi-setting regulation on multiple types of sedentary behaviour in children and adolescents in July 2021. This regulation restricts when (and for how long) online gaming businesses can provide access to pupils; the amount of homework teachers can assign to pupils according to their year groups; and when tutoring businesses can provide lessons to pupils. We evaluated the effect of this regulation on sedentary behaviour safeguarding pupils. METHODS: With a natural experiment evaluation design, we used representative surveillance data from 9- to 18-year-old pupils before and after the introduction of the regulation, for longitudinal (n = 7,054, matched individuals, primary analysis) and repeated cross-sectional (n = 99,947, exploratory analysis) analyses. We analysed pre-post differences for self-reported sedentary behaviour outcomes (total sedentary behaviour time, screen viewing time, electronic device use time, homework time, and out-of-campus learning time) using multilevel models, and explored differences by sex, education stage, residency, and baseline weight status. RESULTS: Longitudinal analyses indicated that pupils had reduced their mean total daily sedentary behaviour time by 13.8% (95% confidence interval [CI]: -15.9 to -11.7%, approximately 46 min) and were 1.20 times as likely to meet international daily screen time recommendations (95% CI: 1.01 to 1.32) one month after the introduction of the regulation compared to the reference group (before its introduction). They were on average 2.79 times as likely to meet the regulatory requirement on homework time (95% CI: 2.47 to 3.14) than the reference group and reduced their daily total screen-viewing time by 6.4% (95% CI: -9.6 to -3.3%, approximately 10 min). The positive effects were more pronounced among high-risk groups (secondary school and urban pupils who generally spend more time in sedentary behaviour) than in low-risk groups (primary school and rural pupils who generally spend less time in sedentary behaviour). The exploratory analyses showed comparable findings. CONCLUSIONS: This regulatory intervention has been effective in reducing total and specific types of sedentary behaviour among Chinese children and adolescents, with the potential to reduce health inequalities. International researchers and policy makers may explore the feasibility and acceptability of implementing regulatory interventions on sedentary behaviour elsewhere.

Neighbourhood walkability and greenspace and their associations with health-related fitness in urban dwelling Canadian adults.

OBJECTIVE: Muscular strength and body composition are important components of health-related fitness (HRF). Grip strength and body fat percent, in particular, are associated with chronic disease and affected by health behaviours. Evidence suggests relationships between the neighbourhood built environment (BE) and HRF exist, however, few studies have focused on grip strength and body fat percent. Therefore, our study aimed to estimate the sex-specific associations between the neighbourhood BE, grip strength, and body fat percent among urban-dwelling Canadian adults. METHODS: We analyzed cross-sectional survey and HRF data collected in 2011-2015 from 4052 males and 7841 females (Alberta's Tomorrow Project, Canada). Grip strength and body fat percent were measured via handgrip dynamometry and bioelectrical impedance analysis, respectively. Walkability (Canadian Active Living Index) and greenness (Normalized Difference Vegetation Index) estimates were linked to participant data. Sex-stratified covariate-adjusted linear regression models estimated the associations between the BE and HRF variables. RESULTS: Walkability was negatively associated with grip strength and body fat percent in males (ß -0.21, 95%CI: -0.31 to -0.11 and ß -0.08, 95%CI: -0.15 to -0.02, respectively) and females (ß -0.06, 95%CI: -0.10 to -0.01 and ß -0.08, 95%CI: -0.14 to -0.02, respectively). Greenness was positively associated with grip strength in males (ß 6.99, 95%CI: 3.62 to 10.36) and females (ß 2.72, 95%CI: 1.22 to 4.22) but not with body fat percent. Controlling for physical activity and sitting did not attenuate these associations. CONCLUSION: Characteristics of the neighbourhood BE appear to be associated with muscular strength and body composition, independent of physical activity and sedentary behaviour.

Telework and 24-hour movement behaviours among adults living in Canada during the COVID-19 pandemic.

OBJECTIVE: To assess the association between work location and movement behaviours (physical activity [PA], screen time, sleep) and adherence to the Canadian 24-Hour Movement Guidelines (24-H Guidelines) among Canadian workers during the COVID-19 pandemic. METHODS: Using cross-sectional data from the 2021 Canadian Community Health Survey (n = 10,913 working adults 18-75 years), primary work location was categorized as: worked outside the home at a fixed location (fixed workplace), worked at home (telework), and worked outside the home at no fixed location (non-fixed workplace). Recreational, transportation and occupational/household PA, as well as leisure screen time and sleep duration were self-reported. Logistic regression assessed associations between work location and adherence to movement behaviour recommendations, adjusting for covariates. RESULTS: Compared to a fixed workplace, those teleworking reported more recreational PA (21.1 vs 17.0 min/day, p < 0.0001) and sleep (7.2 vs 7.1 h/night, p = 0.026) and were more likely to meet sleep duration recommendations (adjusted odds ratio [aOR] = 1.28, 95% CI: 1.08-1.51) and the 24-H Guidelines (aOR = 1.25, 95% CI: 1.04-1.51). Compared to fixed workplaces, those at non-fixed workplaces reported more occupational PA (62.7 vs 32.8 min/day, p < 0.0001) and less leisure screen time (2.5 vs 2.7 h/day, p = 0.021), and were more likely to meet the PA recommendation (aOR = 1.46, 95% CI: 1.15-1.85) and the 24-H Guidelines (aOR = 1.38, 95% CI: 1.09-1.75). CONCLUSIONS: Results suggest that adherence to the 24-H Guidelines varies by work location, and work location should be considered when developing strategies to promote healthy movement behaviours. Future studies could explore hybrid work arrangements, and longitudinal study designs.

A narrative review of global and national physical activity and sedentary behaviour guidelines development processes - The GUidelines Standards (GUS) project.

BACKGROUND: Clinical and public health guidelines serve to direct clinical practice and policy, based on the best available evidence. The World Health Organization (WHO) and national health bodies of many countries have released physical activity and sedentary behaviour guidelines. Despite significant overlap in the body of evidence reviewed, the guidelines differ across jurisdictions. This study aimed to review the processes used to develop global and national physical activity and sedentary behaviour guidelines and examine the extent to which they conform with a recommended methodological standard for the development of guidelines. METHODS: We extracted data on nine sets of guidelines from seven jurisdictions (WHO, Australia, Canada, Japan, the Netherlands, United Kingdom, and United States). We rated each set of guidelines as high, medium, or low quality on criteria related to the rigour of the development process. RESULTS: We observed variation in the quality of guidelines development processes across jurisdictions and across different criteria. Guidelines received the strongest overall ratings for criteria on clearly describing the evidence selected and stating an explicit link between the recommendations and the supporting evidence. Guidelines received the weakest overall ratings for criteria related to clearly describing the methods used to formulate the recommendations and reporting external review by experts prior to publication. Evaluated against the selected criteria, the strongest processes were undertaken by the WHO and Canada. CONCLUSIONS: Reaching agreement on acceptable guideline development processes, as well as the inclusion and appraisal procedures of different types of evidence, would help to strengthen and align future guidelines.

Association of sedentary time with risk of cardiovascular diseases and cardiovascular mortality: A systematic review and meta-analysis of prospective cohort studies.

Given the high prevalence of cardiovascular disease (CVD), we meta-analysed CVD relative risk (RR) in relation to high vs. low categories of self-reported and objectively assessed sedentary behaviours from cohort studies; in a sub-sample (n = 4 studies), the theoretical substitution of one hour spent sedentary with the same amount of time spent in light-intense physical activity was evaluated. Based on 19 studies (60,526 fatal and non-fatal CVD, 1,473,354 individuals and 13,559,139 persons-year) we estimated a 30% increased CVD risk for high vs. low categories of sedentary behaviour (RR = 1.29, confidence interval (CI) = 1.22;1.37). Every hour spent sedentary corresponds to a 5% increased fatal and non-fatal CVD risk (RR = 1.05, CI = 1.02;1.07). Dose-response meta-analysis revealed that sedentary behaviour is statistically significantly associated to fatal and non-fatal CVD risk following a J-shaped relation. Substituting one hour spent sedentary with physical activity of light intensity reduced the risk of fatal and non-fatal CVD events by one-fifth (RR =0.84, CI = 0.73;0.97). In meta-regression analysis, potential influential factors such as age, sex, and medical condition did not essentially alter the results.

Children's physical activity and sedentary behaviour in before school care: An observational study.

OBJECTIVE: In Australia, less than one quarter of children aged 5-12 years meet national physical activity (PA) guidelines. Before school care operates as part of Out of School Hours Care (OSHC) services and provide opportunities for children to meet their daily PA recommendations. The aim of this study was to explore factors associated with children meeting 15 min of moderate-to-vigorous-intensity physical activity (MVPA) while attending before school care. METHODS: A cross-sectional study was conducted in 25 services in New South Wales, Australia. Each service was visited twice between March and June 2021. Staff behaviours and PA type and context were captured using staff interviews and the validated System for Observing Staff Promotion of Physical Activity and Nutrition (SOSPAN) time sampling tool. Child PA data were collected using Actigraph accelerometers and associations between program practices and child MVPA analysed. RESULTS: PA data were analysed for 654 children who spent an average of 39.2% (±17.6) of their time sedentary; 45.4% (±11.4) in light PA; and 14.9% (±11.7) in MVPA. Only 17% of children (n = 112) reached ≥15 min MVPA, with boys more likely to achieve this. Children were more likely to meet this recommendation in services where staff promoted and engaged in PA; PA equipment was available; children were observed in child-led free play; and a written PA policy existed. CONCLUSIONS: Before school care should be supported to improve physical activity promotion practices by offering staff professional development and guidance on PA policy development and implementation practices.

Decrease in accelerometer assessed physical activity during the first-year post-myocardial infarction: a prospective cohort study.

OBJECTIVES: To elucidate physical activity in the first year after myocardial infarction (MI), and to explore differences in various subgroups, delineated by age, participation in exercise-based cardiac rehabilitation (exCR), or restrictions due to the covid-19 pandemic. Secondly, to explore associations between changes in physical activity variables with blood pressure and lipid levels. METHODS: A longitudinal study in 2017-2023. Physical activity variables were assessed via accelerometers at two- and twelve months post-MI. The intensity was divided into, sedentary, light, moderate, and vigorous-intensity physical activity, according to established cut-offs. Blood pressure and lipids were measured by standardized procedures at the same time points. RESULTS: There were 178 patients included at baseline, 81% male, mean age of 64 (9 SD) years. Patients spent 72% of their time sedentary, followed by light (19%), moderate (8%), and vigorous physical activity (1%). Patients included during covid-19 restrictions and younger patients had a higher level of moderate-intensity physical activity compared to patients included during non-pandemic restrictions and older patients. At 12-month follow-up, patients overall increased time (1%) in sedentary behavior (p = 0.03) and decreased time (0.6%) in moderate-intensity physical activity (p = 0.04), regardless of participation in exCR or age. There was a positive association between the change in mean physical activity intensity and HDL-cholesterol (p = 0.047). CONCLUSIONS: Participants had a low fraction of time in moderate-to-vigorous-intensity physical activity two months post-MI, which deteriorated during the first year. This emphasizes the need for improved implementation of evidence-based interventions to support and motivate patients to perform regular physical activity.