Device-measured physical activity and sedentary time in the Nordic countries: A scoping review of population-based studies.

BACKGROUND: The purpose of this scoping review was to summarize and describe the methodology and results from population-based studies of physical activity and sedentary time measured with devices in the Nordic countries (Denmark, Finland, Iceland, Norway, and Sweden) and published in 2000 or later. METHODS: A systematic search was carried out in PubMed and Web of Science in June 2023 using predefined search terms. RESULTS: Fourteen unique research projects or surveillance studies were identified. Additionally, 2 surveillance studies published by national agencies were included, resulting in a total of 16 studies for inclusion. National surveillance systems exist in Finland and Norway, with regular survey waves in school-aged children/adolescents and adults. In Denmark, recent nationally representative data have been collected in school children only. So far, Sweden has no regular national surveillance system using device-based data collection. No studies were found from Iceland. The first study was conducted in 2001 and the most recent in 2022, with most data collected from 2016 to date. Five studies included children/adolescents 6-18 years, no study included preschoolers. In total 11 studies included adults, of which 8 also covered older adults. No study focused specifically on older adults. The analytical sample size ranged from 205 to 27,890. Detailed methodology is presented, such as information on sampling strategy, device type and placement, wear protocols, and physical activity classification schemes. Levels of physical activity and sedentary time in children/adolescents, adults, and older adults across the Nordic countries are presented. CONCLUSION: A growing implementation of device-based population surveillance of physical activity and sedentary behavior in the Nordic countries has been identified. The variety of devices, placement, and data procedures both within and between the Nordic countries highlights the challenges when it comes to comparing study outcomes as well as the need for more standardized data collection.

Joint associations of device-measured physical activity and abdominal obesity with incident cardiovascular disease: a prospective cohort study.

OBJECTIVE: To examine the joint associations between physical activity and abdominal obesity with the risk of cardiovascular disease (CVD) events. METHODS: We included 70 830 UK Biobank participants (mean age±SD=61.6 ± 7.9 years; 56.4% women) with physical activity measured by wrist-worn accelerometers and without major chronic diseases. Participants were jointly categorised into six groups based on their physical activity level (tertiles of total volume and specific intensity levels) and presence or absence of abdominal obesity based on measured waist circumference. Associations with incident CVD (fatal and non-fatal events) were determined using proportional subdistribution hazard models with multivariable adjustment. RESULTS: After excluding events during the first 2 years of follow-up, participants were followed for a median of 6.8 years, during which 2795 CVD events were recorded. Compared with the low abdominal adiposity and highest tertile of physical activity, abdominal obesity was associated with higher risk of incident CVD, especially in those with low levels of vigorous-intensity physical activity (HR 1.42, 95% CI 1.22 to 1.64). Approximately 500 min per week of moderate-to-vigorous intensity and approximately 30-35 min of vigorous-intensity physical activity offset the association of abdominal obesity and the risk of having a CVD event. CONCLUSION: Physical activity equivalent to approximately 30-35 min of vigorous intensity per week appears to offset the association between abdominal obesity and incident CVD. About 15 times more physical activity of at least moderate intensity is needed to achieve similar results.

Leisure-time physical activity and all-cause mortality and cardiovascular disease in adults with type 2 diabetes: Cross-country comparison of cohort studies.

PURPOSE: This study aimed to quantify the dose-response association and the minimal effective dose of leisure-time physical activity (PA) to prevent mortality and cardiovascular disease in adults with type 2 diabetes. METHODS: Cross-country comparison of 2 prospective cohort studies including 14,913 and 17,457 population-based adults with type 2 diabetes from the UK and China. Baseline leisure-time PA was self-reported and categorized by metabolic equivalent hours per week (MET-h/week) according to World Health Organization recommendations: none, below recommendation (>0-7.49 MET-h/week); at recommended level (7.5-14.9 MET-h/week); above recommendation (≥15 MET-h/week). Mortality and cardiovascular disease data were obtained from national registries. RESULTS: During a median follow-up of 12.4 and 9.7 years, in the UK and China cohorts, repectively, higher levels of leisure-time PA were inversely associated with all-cause (1571 and 2351 events) and cardiovascular mortality (392 and 1060 events), mostly consistent with a linear dose-response relationship. PA below, at, and above recommendations, compared with no activity, yielded all-cause mortality hazard ratios of 0.94 (95% confidence interval (95%CI): 0.79-1.12), 0.90 (95%CI: 0.74-1.10), and 0.85 (95%CI: 0.70-1.02) in British adults and 0.87 (95%CI: 0.68-1.10), 0.88 (95%CI: 0.74-1.03), and 0.77 (95%CI: 0.70-0.85) in Chinese adults. Associations with cardiovascular mortality were more pronounced in British adults (0.80 (95%CI: 0.58-1.11), 0.75 (95%CI: 0.52-1.09), and 0.69 (95%CI: 0.48-0.97)) but less pronounced in Chinese adults (1.06 (95%CI: 0.76-1.47), 1.01 (95%CI: 0.80-1.28), and 0.79 (95%CI: 0.69-0.92)). PA at recommended levels was not associated with lower rates of major adverse cardiovascular events (2345 and 4458 events). CONCLUSION: Leisure-time PA at the recommended levels was not convincingly associated with lower mortality and had no association with risk of major adverse cardiovascular events in British or Chinese adults with type 2 diabetes. Leisure-time PA above current recommendations may be needed to prevent cardiovascular disease and premature mortality in adults with type 2 diabetes.

Dose-response associations, physical activity intensity and mortality risk: A narrative review.

Physical activity is consistently associated with reduced mortality, decreased risk for non-communicable diseases, and improved mental health in observational studies. Randomized controlled trials and observational Mendelian randomization studies support causal links between physical activity and health outcomes. However, the scarcity of evidence from randomized controlled trials, along with their inherent challenges like exposure contrasts, healthy volunteer biases, loss to follow-up, and limited real-world dose-response data, warrants a comprehensive approach. This review advocates synthesizing insights from diverse study designs to better understand the causal relationship between physical activity, mortality risk, and other health outcomes. Additionally, it summarizes recent research since the publication of current physical activity recommendations. Novel observational studies utilizing device-measured physical activity underscore the importance of every minute of activity and suggest that all intensity levels confer health benefits, with vigorous-intensity potentially requiring lower volumes for substantial benefits. Future guidelines, informed by device-measured physical activity studies, may offer refined age-specific recommendations, emphasize vigorous-intensity physical activity, and include daily step counts as a simple, easily assessable metric using commercial wearables.

Device-measured physical activity, sedentary time, and risk of all-cause mortality: an individual participant data analysis of four prospective cohort studies.

OBJECTIVES: To examine whether moderate-to-vigorous physical activity (MVPA) modifies the association between sedentary time and mortality and vice versa, and estimate the joint associations of MVPA and sedentary time on mortality risk. METHODS: This study involved individual participant data analysis of four prospective cohort studies (Norway, Sweden, USA, baseline: 2003-2016, 11 989 participants ≥50 years, 50.5% women) with hip-accelerometry-measured physical activity and sedentary time. Associations were examined using restricted cubic splines and fractional polynomials in Cox regressions adjusted for sex, education, body mass index, smoking, alcohol, study cohort, cardiovascular disease, cancer, and/or diabetes, accelerometry wear time and age. RESULTS: 6.7% (n=805) died during follow-up (median 5.2 years, IQR 4.2 years). More than 12 daily sedentary hours (reference 8 hours) was associated with mortality risk only among those accumulating <22 min of MVPA per day (HR 1.38, 95% CI 1.10 to 1.74). Higher MVPA levels were associated with lower mortality risk irrespective of sedentary time, for example, HR for 10 versus 0 daily min of MVPA was 0.85 (95% CI 0.74 to 0.96) in those accumulating <10.5 daily sedentary hours and 0.65 (95% CI 0.53 to 0.79) in those accumulating ≥10.5 daily sedentary hours. Joint association analyses confirmed that higher MVPA was superior to lower sedentary time in lowering mortality risk, for example, 10 versus 0 daily min of MVPA was associated with 28-55% lower mortality risk across the sedentary time spectrum (lowest risk, 10 daily sedentary hours: HR 0.45, 95% CI 0.31 to 0.65). CONCLUSIONS: Sedentary time was associated with higher mortality risk but only in individuals accumulating less than 22 min of MVPA per day. Higher MVPA levels were associated with lower mortality risk irrespective of the amount of sedentary time.

Leisure-Time Physical Activity and Risk of Microvascular Complications in Individuals With Type 2 Diabetes: A UK Biobank Study.

OBJECTIVE: The aim of this study was to determine dose-response associations, including the minimal effective level, between leisure-time physical activity and risk of incident neuropathy, nephropathy, and retinopathy. RESEARCH DESIGN AND METHODS: This cohort study included 18,092 individuals with type 2 diabetes from the UK Biobank. Self-reported leisure-time physical activity was converted into MET-hours per week. Participants were categorized into no physical activity (0 MET-h/week), below recommendations (0-7.49 MET-h/week), at recommendations (7.5-14.9 MET-h/week), and above recommendations (≥15 MET-h/week). Microvascular complications were identified from hospital inpatient records using diagnosis codes. We used Cox proportional hazards regression analysis to calculate adjusted hazard ratios (aHRs) and restricted cubic splines to identify the minimal effective level of physical activity. RESULTS: During a median follow-up of 12.1 years, 672 individuals (3.7%) were diagnosed with neuropathy, 1,839 (10.2%) with nephropathy, and 2,099 (11.7%) with retinopathy. Any level of physical activity was associated with a lower risk of neuropathy and nephropathy but not retinopathy. Compared with those reporting no physical activity, the aHR of neuropathy was 0.71 (95% CI 0.53, 0.90) below recommendations, 0.73 (0.56, 0.96) at recommendations, and 0.67 (0.52, 0.87) above recommendations. Corresponding aHRs for nephropathy were 0.79 (0.68, 0.92), 0.80 (0.67, 0.95), and 0.80 (0.68, 0.95). The association with retinopathy was weaker, with aHRs of 0.91 (0.78, 1.06), 0.91 (0.77, 1.08), and 0.98 (0.84, 1.15), respectively. CONCLUSIONS: Any level of leisure-time physical activity was associated with a lower risk of neuropathy and nephropathy but not retinopathy in individuals with type 2 diabetes. For both neuropathy and nephropathy, the minimal effective physical activity level may correspond to <1.5 h of walking per week.

Body composition and mortality from middle to old age: a prospective cohort study from the UK Biobank.

BACKGROUND: How the association between adiposity and the risk of death changes with age, and which is the optimal level of adiposity to reduce mortality in older ages, is still not completely understood. We aimed to ascertain the age-specific risks of mortality associated with different measures of adiposity. METHODS: This was a prospective UK Biobank cohort study. Participants were categorized based on five different adiposity and body composition metrics. We explored the age-varying associations between body composition indices and all-cause mortality from 45 to 85 years of age at follow-up using hazard ratios (HR) from flexible parametric survival models with multivariable adjustment and age as timescale. Participants were followed from baseline (2006-2010) through 31 March 2020. RESULTS: We included 369,752 participants (mean baseline age = 56.3 ± 8.1 years; range 38.9-73.7 years; 54.1% women) and 10,660 deaths during a median follow-up of 11.4 years. Associations between body mass index and mortality were similar when using the fat mass index in magnitude and shape. Compared to participants with normal weight, overweight was not associated with the risk of death regardless of age and the adiposity measure used. Participants with obesity class I showed an HR of 1.20 (95% confidence interval [CI]: 1.08, 1.33) and 1.14 (95%CI: 0.98, 1.30) at ages 60 and 80, respectively, and participants with obesity class II an HR about 1.55 across all age. More attenuated associations with higher age were found in individuals with the highest obesity using the fat mass index. Very high lean mass was associated with an increased risk of mortality in those aged 55-75 years (HR about 1.20 across all ages). CONCLUSION: Obesity should be prevented at any age. Attenuated associations with older age were observed only among the individuals with the highest obesity, but the risk remained higher compared to normal-weight participants. Lean mass did not reduce mortality risk at any age.

Joint associations of physical activity and sedentary time with body mass index: A prospective study of mortality risk.

Device-measured physical activity and sedentary time are suggested to be more important determinants of all-cause mortality compared to body mass index (BMI) in mainly older adults. However, the joint associations of physical activity and sedentary time with BMI in relation to mortality risk in relatively healthy middle-aged individuals are unclear. We followed 770 adults (56% women, mean age 55.6 years) from a population-based cohort study for up to 15.3 years. BMI categories were combined with tertiles of total, light, and moderate-to-vigorous physical activity and sedentary time. Cox proportional hazards models estimated hazard ratios (HR) of all-cause mortality with 95% confidence intervals (CI). High total and light intensity physical activity and low sedentary time were associated with a lower risk of mortality in normal weight individuals compared with low active overweight/obese; HR: 0.35 (CI: 0.14, 0.86), HR: 0.33 (CI: 0.12, 0.89), and HR: 0.34 (CI: 0.13, 0.92). Among overweight/obese individuals, those who were medium active in light physical activity had a lower mortality risk, HR: 0.36 (CI: 0.15, 0.83), compared with low active. Medium sedentary individuals had a lower risk, HR: 0.43 (CI: 0.20, 0.94) compared with those who were most sedentary. Associations among the most active or least sedentary tertiles were similar irrespective of BMI category. In conclusion, higher physical activity and lower sedentary time were associated with lower mortality risk irrespective of BMI. Physical activity should be promoted and prescribed to individuals with low physical activity levels irrespective of weight status.

Socioeconomic position, built environment and physical activity among children and adolescents: a systematic review of mediating and moderating effects.

BACKGROUND: Physical activity behaviors among children and adolescents are socioeconomically patterned. Understanding if, and how, the built environment contributes to socioeconomic inequalities in physical activity and for whom built environments are most important, can lead to the identification of intervention entry points to reduce inequalities in physical activity. OBJECTIVE: To summarize the existing evidence among children and adolescents on (a) whether the built environment mediates the association between socioeconomic position and physical activity and (b) whether socioeconomic position moderates the association between the built environment and physical activity. METHODS: A systematic literature search was conducted using PubMed, Embase, PsycINFO and Web of Science. Two independent reviewers screened articles for eligibility, extracted information from included studies and assessed risk of bias with the Quality Assessment Tool for Observational Cohort and Cross-Sectional studies. We performed a narrative evidence synthesis considering the totality of the evidence and by study characteristics such as geographic region, age group, and exposure-outcome assessment methodology. The reporting was conducted in agreement with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. RESULTS: A total of 28 papers were included. In general, the studies were of low methodological quality. There was no evidence to support that the built environment functions as a mediator in the relationship between socioeconomic position and physical activity. We observed inconclusive moderation patterns with five studies reporting stronger associations between features of the built environment and physical activity among high socioeconomic positioned youths. Seven studies reported stronger associations among low socioeconomic positioned youth and fourteen studies reported no difference in associations. We observed different moderation patterns across geographical regions (Europe vs. US) indicating that, in Europe, having a walkable neighborhood is important for low socioeconomic positioned youth only. No differences in moderation patterns were observed for younger vs. older children or activity domains. CONCLUSION: Current evidence does not support a strong interplay between built environment and socioeconomic position on physical activity in youth. However, given the low quality of the evidence, firm conclusions cannot be made, and additional high-quality research is likely to have substantial impact on the evidence base.

The metabolic syndrome is frequent in children and adolescents with type 1 diabetes compared to healthy controls.

OBJECTIVE: There is a rise in overweight and obesity among children and adolescents with type 1 diabetes (T1D) in parallel with the rise in the metabolic syndrome (MetS) among children and adolescents. The aim of the study was to describe the prevalence and characteristics of MetS in children and adolescents with T1D compared to their healthy counterparts. RESEARCH DESIGN AND METHODS: The study includes two Danish cohorts; (i) the Copenhagen cross sectional cohort 2016 of 277 children and adolescents with T1D that attend the pediatric outpatient clinic at a large hospital in greater Copenhagen and (ii) the CHAMPS-study DK which is a population-based cohort study of Danish children and adolescents (control cohort). Participants were categorized to have MetS if at least two of the following criteria were met: (i) systolic and/or diastolic blood pressure ≥ 90th percentile, (ii) waist circumference ≥90th percentile, and (iii) triglyceride ≥90th percentile and/or HDL ≤10th percentile. RESULTS: The prevalence of children with Mets in the T1D cohort was higher than in the control cohort (p = 0.002). Moreover, participants with T1D had MetS at a lower level of BMI (p < 0.001) and waist circumference (p < 0.001) than participants with MetS from the control cohort (z-scores = 0.90 and 1.51). Participants with MetS were younger than the other T1D participants (median 12.8 [9.9,14.8] vs. median 14.6 [11.2,16.9] years, p = 0.006). CONCLUSIONS: Children and adolescents with T1D have an increased risk of MetS compared to healthy controls and clinicians and caretakers should consider early prevention and health promotion strategies.

Device-measured sedentary time in Norwegian children and adolescents in the era of ubiquitous internet access: secular changes between 2005, 2011 and 2018.

BACKGROUND: Access to screen-based media has been revolutionized during the past two decades. How this has affected sedentary time (ST) accumulation in children is poorly understood. METHODS: This study, based on the Physical Activity among Norwegian Children Study (PANCS), uses accelerometer data from population-based samples of 9- and 15-year-olds, collected in 2005 (n = 1722), 2011 (n = 1587) and 2018 (n = 1859). Secular changes between surveys were analysed using random-effects linear regression models adjusted for survey-specific factors. Data on ST were collected using hip-worn ActiGraphs and ST was defined using a threshold equivalent to <100 counts/min. Sedentary bouts were grouped by duration: <1, 1-5, 5-15, 15-30 and ≥30 min. RESULTS: Between 2005 and 2018, ST increased by 29 min/day in 9-year-old boys (95% CI: 19, 39; P <0.001), by 21 min/day in 15-year-old boys (95% CI: 8, 34; P = 0.002) and by 22 min/day in 15-year-old girls (95% CI: 10, 35; P <0.001), but not in 9-year-old girls at 6 min/day (95% CI: -3, 16; P = 0.191). All age-sex groups accumulated less ST in bouts lasting <5 min and more ST in longer bouts, particularly in 5-15-min bouts. Adolescent girls also increased ST accumulation in 15-30-min and ≥30-min bouts. Changes were largely mirrored before, during and after school on weekdays and during weekend days. CONCLUSIONS: Coinciding with the introduction of smartphones, tablets and near-universal internet access, total daily ST and ST accumulated in prolonged sedentary bouts increased between 2005 and 2018 in children and adolescents.

Recommendations for Determining the Validity of Consumer Wearables and Smartphones for the Estimation of Energy Expenditure: Expert Statement and Checklist of the INTERLIVE Network.

BACKGROUND: Consumer wearables and smartphone devices commonly offer an estimate of energy expenditure (EE) to assist in the objective monitoring of physical activity to the general population. Alongside consumers, healthcare professionals and researchers are seeking to utilise these devices for the monitoring of training and improving human health. However, the methods of validation and reporting of EE estimation in these devices lacks rigour, negatively impacting on the ability to make comparisons between devices and provide transparent accuracy. OBJECTIVES: The Towards Intelligent Health and Well-Being Network of Physical Activity Assessment (INTERLIVE) is a joint European initiative of six universities and one industrial partner. The network was founded in 2019 and strives towards developing best-practice recommendations for evaluating the validity of consumer wearables and smartphones. This expert statement presents a best-practice validation protocol for consumer wearables and smartphones in the estimation of EE. METHODS: The recommendations were developed through (1) a systematic literature review; (2) an unstructured review of the wider literature discussing the potential factors that may introduce bias during validation studies; and (3) evidence-informed expert opinions from members of the INTERLIVE network. RESULTS: The systematic literature review process identified 1645 potential articles, of which 62 were deemed eligible for the final dataset. Based on these studies and the wider literature search, a validation framework is proposed encompassing six key domains for validation: the target population, criterion measure, index measure, testing conditions, data processing and the statistical analysis. CONCLUSIONS: The INTERLIVE network recommends that the proposed protocol, and checklists provided, are used to standardise the testing and reporting of the validation of any consumer wearable or smartphone device to estimate EE. This in turn will maximise the potential utility of these technologies for clinicians, researchers, consumers, and manufacturers/developers, while ensuring transparency, comparability, and replicability in validation. TRIAL REGISTRATION: PROSPERO ID: CRD42021223508.

Device-measured physical activity, adiposity and mortality: a harmonised meta-analysis of eight prospective cohort studies.

BACKGROUND: The joint associations of total and intensity-specific physical activity with obesity in relation to all-cause mortality risk are unclear. METHODS: We included 34 492 adults (72% women, median age 62.1 years, 2034 deaths during follow-up) in a harmonised meta-analysis of eight population-based prospective cohort studies with mean follow-up ranging from 6.0 to 14.5 years. Standard body mass index categories were cross-classified with sample tertiles of device-measured total, light-to-vigorous and moderate-to-vigorous physical activity and sedentary time. In five cohorts with waist circumference available, high and low waist circumference was combined with tertiles of moderate-to-vigorous physical activity. RESULTS: There was an inverse dose-response relationship between higher levels of total and intensity-specific physical activity and mortality risk in those who were normal weight and overweight. In individuals with obesity, the inverse dose-response relationship was only observed for total physical activity. Similarly, lower levels of sedentary time were associated with lower mortality risk in normal weight and overweight individuals but there was no association between sedentary time and risk of mortality in those who were obese. Compared with the obese-low total physical activity reference, the HRs were 0.59 (95% CI 0.44 to 0.79) for normal weight-high total activity and 0.67 (95% CI 0.48 to 0.94) for obese-high total activity. In contrast, normal weight-low total physical activity was associated with a higher risk of mortality compared with the obese-low total physical activity reference (1.28; 95% CI 0.99 to 1.67). CONCLUSIONS: Higher levels of physical activity were associated with lower risk of mortality irrespective of weight status. Compared with obesity-low physical activity, there was no survival benefit of being normal weight if physical activity levels were low.

Accelerometer-derived physical activity and sedentary behaviors in individuals with newly diagnosed type 2 diabetes: A cross-sectional study from the Danish nationwide DD2 cohort.

Introduction: Habitual physical activity behaviors of individuals with new-onset type 2 diabetes are largely unknown. We aimed to investigate accelerometer-derived physical activity behaviors in individuals with newly diagnosed type 2 diabetes. We also examined sociodemographic and health-related correlates of a high-risk physical activity profile. Methods: This cross-sectional study used data from 768 participants enrolled in an intervention study nested within the Danish Centre for Strategic Research in Type 2 diabetes (DD2) cohort. Physical activity was assessed by 24-h dual monitor accelerometry. Prevalence ratios of having a high-risk physical activity profile were estimated using Poisson regression adjusted for age and sex. Results: Study participants spent on average 9.7 (25th and 75th percentiles, 8.3; 11.1) hours/day sitting, walked for 1.1 (0.8; 1.6) hours/day and accumulated 4,000 (2,521; 5,864) steps/day. Still, 62% met the recommendations for physical activity. Characteristics associated with a high-risk physical activity profile (observed in 24.5% of participants) included older age, higher body mass index (BMI), unemployment, retirement, comorbidities, and current smoking. Hence, participants aged 60-69, 70-79 and 80+ years had prevalence ratios of 2.12 (95% CI 1.31; 3.42), 1.99 (1.18; 3.34) and 3.09 (1.42; 6.75) for a high-risk activity profile, respectively, versus participants <50 years. BMI values of 30-39 and 40+ were associated with 1.83 (1.06; 3.15) and 3.38 (1.88; 6.05) higher prevalence ratios compared to normal-weight. Unemployment or retirement was associated with 1.62 (1.09; 2.41) and 2.15 (1.37; 3.39) times higher prevalence ratios, compared to individuals in the working force. Having a Charlson Comorbidity Index score of 1-2 or 3+ was associated with 1.36 (1.03-1.79) and 1.90 (1.27-1.84) higher prevalence ratios, while current smoking was associated with a prevalence ratio of 1.72 (1.25; 2.35) compared to never smokers. Conclusion: This study shows that 62% of individuals with newly diagnosed type 2 diabetes met the recommendations for physical activity. Still, the majority of participants were also highly sedentary and accumulated very few daily steps, emphasizing the need for focusing on both increasing physical activity and reducing sedentary behaviors in the prevention of diabetes-related complications. Individuals with a high-risk physical activity profile were characterized by more obesity, socioeconomic inequalities, advanced age and comorbidities.Trial registration number: NCT02015130.

Occupational physical activity and longevity in working men and women in Norway: a prospective cohort study.

BACKGROUND: Studies suggest that high occupational physical activity increases mortality risk. However, it is unclear whether this association is causal or can be explained by a complex network of socioeconomic and behavioural factors. We aimed to examine the association between occupational physical activity and longevity, taking a complex network of confounding variables into account. METHODS: In this prospective cohort study, we linked data from Norwegian population-based health examination surveys, covering all parts of Norway with data from the National Population and Housing Censuses and the Norwegian Cause of Death Registry. 437 378 participants (aged 18-65 years; 48·7% men) self-reported occupational physical activity (mutually exclusive groups: sedentary, walking, walking and lifting, and heavy labour) and were followed up from study entry (between February, 1974, and November, 2002) to death or end of follow-up on Dec 31, 2018, whichever came first. We estimated differences in survival time (death from all causes, cardiovascular disease, and cancer) between occupational physical activity categories using flexible parametric survival models adjusted for confounding factors. FINDINGS: During a median of 28 years (IQR 25-31) from study entry to the end of follow-up, 74 203 (17·0%) of the participants died (all-cause mortality), of which 20 111 (27·1%) of the deaths were due to cardiovascular disease and 29 886 (40·3%) were due to cancer. Crude modelling indicated shorter mean survival times among men in physically active occupations than in those with sedentary occupations. However, this finding was reversed following adjustment for confounding factors (birth cohort, education, income, ethnicity, prevalent cardiovascular disease, smoking, leisure-time physical activity, body-mass index), with estimates suggesting that men in occupations characterised by walking, walking and lifting, and heavy labour had life expectancies equivalent to 0·4 (95% CI -0·1 to 1·0), 0·8 (0·3 to 1·3), and 1·7 (1·2 to 2·3) years longer, respectively, than men in the sedentary referent category. Results for mortality from cardiovascular disease and cancer showed a similar pattern. No clear differences in survival times were observed between occupational physical activity groups in women. INTERPRETATION: Our results suggest that moderate to high occupational physical activity contributes to longevity in men. However, occupational physical activity does not seem to affect longevity in women. These results might inform future physical activity guidelines for public health. FUNDING: The Norwegian Research Council (grant number 249932/F20).

Fitness, Fatness, and Mortality in Men and Women From the UK Biobank: Prospective Cohort Study.

Background Cardiorespiratory fitness may moderate the association between obesity and all-cause mortality (ie, the "fat-but-fit" hypothesis), but unaddressed sources of bias are a concern. Methods and Results Cardiorespiratory fitness was estimated as watts per kilogram from a submaximal bicycle test in 77 169 men and women from the UK Biobank cohort and combined with World Health Organization standard body mass index categories, yielding 9 unique fitness-fatness combinations. We also formed fitness-fatness combinations based on bioimpedance as a direct measure of body composition. All-cause mortality was ascertained from death registries. Multivariable-adjusted Cox regression models were used to estimate hazard ratios and 95% CIs. We examined the association between fitness-fatness combinations and all-cause mortality in models with progressively more conservative approaches for accounting for reverse causation, misclassification of body composition, and confounding. Over a median follow-up of 7.7 years, 1731 participants died. In our base model, unfit men and women had higher risk of premature mortality irrespective of levels of adiposity, compared with the normal weight-fit reference. This pattern was attenuated but maintained with more conservative approaches in men, but not in women. In analysis stratified by sex and excluding individuals with prevalent major chronic disease and short follow-up and using direct measures of body composition, mortality risk was 1.78 (95% CI, 1.17-2.71) times higher in unfit-obese men but not higher in obese-fit men (0.94 [95% CI, 0.60-1.48]). In contrast, there was no increased risk in obese-unfit women (1.09 [95% CI, 0.44-1.05]) as compared with the reference. Conclusions Cardiorespiratory fitness modified the association between obesity and mortality in men, but this pattern appeared susceptible to biases in women.

Stair climbing and mortality: a prospective cohort study from the UK Biobank.

BACKGROUND: Regular stair climbing has the potential to lower the risk of premature death, but current evidence is scarce. We aimed to examine whether daily stair climbing is associated with lower risk of all-cause, cancer, and cardiovascular disease (CVD) mortality. METHODS: Using the UK Biobank cohort, we extracted information of self-reported daily flights of stairs climbed at home, categorized as none, 1 to 5, 6 to 10, 11 to 15, and ≥16 flights per day. Associations between flights of stair climbed per day and mortality were examined as hazard ratios (HRs) from Cox proportional hazards models adjusted for demographic, clinical, and behavioural covariates including time spent in other physical activities. We calculated the restricted mean survival time as an absolute measure of association. The risk of residual confounding was examined using propensity score matching and by using lung cancer as negative control outcome. Participants were followed from baseline (2006-2010) through 31 March 2020. RESULTS: A total of 280 423 participants (median follow-up 11.1 years, during which 9445 deaths occurred) were included. Compared with not climbing any stairs, climbing more than five flights of stairs at home per day was associated with lower risk of premature mortality. The lowest risk was found for those climbing 6-10 flights per day: 0.91; 95% confidence interval (CI): 0.85, 0.98, translated to approximately 44 to 55 days of additional survival. A similar pattern was found after applying propensity score matching and for cancer mortality (6-10 flights per day HR: 0.88; 95% CI: 0.80, 0.97), but not for CVD mortality (6-10 flights per day HR: 1.08; 95% CI: 0.91, 1.29). The association between stair climbing and lung cancer was similar to that of all-cause mortality. CONCLUSIONS: Climbing more than five flights of stairs at home per day was associated with a lower risk of all-cause and cancer mortality, but not CVD mortality, compared with those who did not take the stairs. The magnitude of the association was small and appeared susceptible to residual confounding. It is unlikely that at-home stair climbing is sufficient physical activity stimuli to lower the risk of premature mortality.

School-based interventions modestly increase physical activity and cardiorespiratory fitness but are least effective for youth who need them most: an individual participant pooled analysis of 20 controlled trials.

OBJECTIVES: To determine if subpopulations of students benefit equally from school-based physical activity interventions in terms of cardiorespiratory fitness and physical activity. To examine if physical activity intensity mediates improvements in cardiorespiratory fitness. DESIGN: Pooled analysis of individual participant data from controlled trials that assessed the impact of school-based physical activity interventions on cardiorespiratory fitness and device-measured physical activity. PARTICIPANTS: Data for 6621 children and adolescents aged 4-18 years from 20 trials were included. MAIN OUTCOME MEASURES: Peak oxygen consumption (VO2Peak mL/kg/min) and minutes of moderate and vigorous physical activity. RESULTS: Interventions modestly improved students' cardiorespiratory fitness by 0.47 mL/kg/min (95% CI 0.33 to 0.61), but the effects were not distributed equally across subpopulations. Girls and older students benefited less than boys and younger students, respectively. Students with lower levels of initial fitness, and those with higher levels of baseline physical activity benefitted more than those who were initially fitter and less active, respectively. Interventions had a modest positive effect on physical activity with approximately one additional minute per day of both moderate and vigorous physical activity. Changes in vigorous, but not moderate intensity, physical activity explained a small amount (~5%) of the intervention effect on cardiorespiratory fitness. CONCLUSIONS: Future interventions should include targeted strategies to address the needs of girls and older students. Interventions may also be improved by promoting more vigorous intensity physical activity. Interventions could mitigate declining youth cardiorespiratory fitness, increase physical activity and promote cardiovascular health if they can be delivered equitably and their effects sustained at the population level.

Does Additional Physical Education Improve Exam Performance at the End of Compulsory Education? A Secondary Analysis from a Natural Experiment: The CHAMPS-Study DK.

It remains unclear whether the provision of additional physical activity in school improves academic outcomes. We conducted a secondary analysis of the Childhood Health, Activity, and Motor Performance School Study Denmark (CHAMPS-study DK), a natural experiment based on a trebling of curricular physical education, to investigate whether children receiving additional physical education performed better on their academic exams at the conclusion of compulsory education (i.e., 9th grade). Children from six intervention schools received 3-7 years of exposure to 270 weekly minutes of physical education (sports schools), while children from four control schools received the 90-min national standard (normal schools). Academic performance was based on the standard Danish 7-point scale (ranging from -03 to 12) and retrieved from national registries. The primary outcome was calculated as the average exam grade. Comparisons of participants at sports and normal schools were adjusted for individual socioeconomic factors and school-level academic environment. There were no differences in the pooled exam performance among 691 sports- and 510 normal-school participants (0.20 (95% confidence interval: -0.12 to 0.52)). Results for subject-specific exams indicated similar results. This analysis from a non-randomized natural experiment did not provide evidence that simply adding additional physical education is sufficient to affect academic performance relative to the national standard.