Reallocating time to sleep, sedentary behaviors, or active behaviors: associations with cardiovascular disease risk biomarkers, NHANES 2005-2006

Associations of low-intensity light physical activity with physical performance in community-dwelling elderly Japanese: A cross-sectional study

Background

Physical activity and physical performance relate to quality of life, mortality, and morbidity in elderly people. However, little is known about differences in physical performance related to low-intensity light physical activity (LLPA), high-intensity light physical activity (HLPA), and moderate-intensity physical activity (MPA) and how they are separated by sex in elderly populations.

Aims

This study aimed to determine differences in LLPA, HLPA, MPA, and physical performance, and associations between these measures in community-dwelling elderly men and women.

Methods

Physical activity and physical performance such as timed-up-and-go test, one-leg standing time, and maximum gait speed were measured in 181 community-dwelling elderly men (mean age, 75.1 ± 5.3 years) and 109 women (mean age, 73.4 ± 4.8 years) in 2013. Physical activity was classified as LLPA (1.6~1.9 METs of physical activity), HLPA (2.0~2.9 METs of physical activity), and MPA (over 3 METs of physical activity). The association between the values of these three intensities of physical activity in the participants was assessed by Pearson’s correlation coefficients. Multiple linear regression analyses were used to assess the association of physical performance values with the three groups defined by accelerometer-measured physical activity intensity adjusted for sociographic, behavioral, and multiple diseases in the participants.

Results

MPA was beneficially associated with all physical performance indicators in the men (all P<0.05) and women (all P<0.05). Only HLPA showed significant associations with the timed-up-and-go test (P = 0.001) and maximum gait speed (P = 0.006) in women.

Discussion

These results may support the notion that not only HLPA in women but MPA in both sexes appears to improve physical performance in elderly populations.

Conclusion

The present study findings provide novel epidemiological evidence for the potential benefits of HLPA in women and also reinforce the potential benefits of MPA in both sexes, which is the mainstay of public health recommendations.

Screen Time and Health Indicators Among Children and Youth: Current Evidence, Limitations and Future Directions

Despite accumulating evidence linking screen-based sedentary behaviours (i.e. screen time) with poorer health outcomes among children and youth <18 years of age, the prevalence of these behaviours continues to increase, with roughly half of children and youth exceeding the public health screen time recommendation of 2 h per day or less. The purpose of this article is to provide an overview of key research initiatives aimed at understanding the associations between screen time and health indicators including physical health, quality of life and psychosocial health. Available evidence suggests that screen time is deleteriously associated with numerous health indicators in child and youth populations, including adiposity, aerobic fitness, quality of life, self-esteem, pro-social behaviour, academic achievement, depression and anxiety. However, few longitudinal or intervention studies have been conducted, with most of these studies focusing on physical health indicators. While most studies have used self-reported assessments of screen time, the availability of more objective assessment methods presents important opportunities (e.g. more accurate and precise assessment of sedentary time and screen time) and challenges (e.g. privacy and participant burden). Novel statistical approaches such as isotemporal substitution modelling and compositional analysis, as well as studies using longitudinal and experimental methodologies, are needed to better understand the health impact of excessive screen time, and to develop strategies to minimise or reverse the negative impacts of these behaviours. The evidence to date suggests a clear need for policy aimed at minimising the hazardous health consequences associated with screen time among children and youth.

Sex and age differences in the associations between sleep behaviors and all-cause mortality in older adults: results from the National Health and Nutrition Examination Surveys

OBJECTIVE

Our aim was to examine sex- and age-specific relationships of sleep behaviors with all-cause mortality rates.

METHODS

A retrospective cohort study was conducted among 5288 adults (≥50 years) from the 2005-2008 National Health and Nutrition Examination Surveys who were followed-up for 54.9 ± 1.2 months. Sleep duration was categorized as < 7 h, 7-8 h and >8 h. Two sleep quality indices were generated through factor analyses. 'Help-seeking behavior for sleep problems' and 'diagnosis with sleep disorders' were defined as yes/no questions. Sociodemographic covariates-adjusted Cox regression models were applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

A positive relationship was observed between long sleep and all-cause mortality rate in the overall sample (HR = 1.90, 95% CI: 1.38, 2.60), among males (HR = 1.48, 95% CI: 1.05, 2.09), females (HR = 2.32, 95% CI: 1.48, 3.61) and elderly (≥65 years) people (HR = 1.80, 95% CI: 1.30, 2.50). 'Sleepiness/sleep disturbance' (Factor I) and all-cause mortality rate were positively associated among males (HR = 1.22, 95% CI: 1.03, 1.45), whereas 'poor sleep-related daytime dysfunction' (Factor II) and all-cause mortality (HR = 0.75, 95% CI: 0.62, 0.91) were negatively associated among elderly people.

CONCLUSIONS

Sex- and age-specific relationships were observed between all-cause mortality rate and specific sleep behaviors among older adults.

Objectively Measured Sedentary Time and Cardiovascular Risk Factor Control in US Hispanics/Latinos With Diabetes Mellitus: Results From the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

BACKGROUND

Cardiovascular disease (CVD) risk factor control is a cornerstone of diabetes mellitus management. Little is known about relationships of objectively measured sedentary time and physical activity with major CVD risk factor control in individuals with diabetes mellitus. We examined associations of objectively measured sedentary time and moderate-to-vigorous physical activity with reaching major CVD risk factor control goals among US Hispanic/Latino adults with diabetes mellitus.

METHODS AND RESULTS

This cross-sectional analysis included 1699 participants with diabetes mellitus from the Hispanic Community Health Study/Study of Latinos (2008-2011). Logistic regression models were used to estimate the odds ratios (ORs) of meeting the following 5 major CVD risk factor control goals: hemoglobin A1c <7.0%; systolic/diastolic blood pressure <140/80 mm Hg; triglycerides <150 mg/dL; low-density lipoprotein cholesterol <100 mg/dL; and high-density lipoprotein cholesterol >40/50 mg/dL for men/women. After adjustment for covariates including moderate-to-vigorous physical activity, less sedentary time was associated with increased odds of reaching hemoglobin A1c (OR=1.76 [95% CI: 1.10, 2.82]) and triglyceride control goals (OR=2.16 [1.36, 3.46]), and reaching ≥3 CVD risk factor control goals (OR=2.08 [1.34, 3.23]) (all ORs for comparisons of extreme tertiles of sedentary time). Moderate-to-vigorous physical activity was not associated with reaching any CVD risk factor control goals. Substituting 60-min/day of sedentary time with light-intensity physical activity was associated with increased odds of reaching hemoglobin A1c (OR=1.18 [1.04, 1.35]), high-density lipoprotein cholesterol (OR=1.17 [1.04, 1.32]), and triglyceride (OR=1.20 [1.05, 1.36]) control goals.

CONCLUSIONS

Among US Hispanic/Latino adults with diabetes mellitus, less sedentary time, but not moderate-to-vigorous physical activity, was associated with improved CVD risk factor control, specifically in reaching hemoglobin A1c and triglyceride control goals.

Breaking Up Sedentary Behavior: Perceptions From Cancer Survivors

BACKGROUND

Limited data exist on the benefits of, barriers to, and potential strategies to break up time spent sitting in cancer survivors. Such data will be meaningful given the consequences of prolonged sitting.

OBJECTIVES

The aim of this study was to conduct a mixed-method research study consisting of semistructured telephone interviews to identify recurrent themes associated with prolonged sitting in cancer survivors.

METHODS

African American breast cancer survivors (N = 31) were recruited from a local tumor registry. Telephone interviews were conducted and group consensus processes were used to identify recurrent themes. The a priori categories were benefits, barriers, and potential strategies to breaking up prolonged periods of sitting.

RESULTS

Recurrent themes contributing most to prolonged sitting were leisure time interest (45%: eg, watching television and reading) and health challenges (27%: eg, pain and fatigue). Most (66%) women perceived improved health as benefits to breaking up time spent sitting. Nonetheless, many (41%) survivors reported health (eg, pain and fatigue) as the biggest challenge to interrupt time spent sitting. Engaging in light intensity activities (eg, staying active, keep moving) was the most commonly reported strategy for breaking up prolonged sitting.

CONCLUSIONS

African American breast cancer survivors identified the benefits and barriers to breaking up time spent sitting as well as potential strategies to interrupt time-spent sitting.

IMPLICATIONS FOR PRACTICE

Clinicians are integral in promoting breaks from prolonged sitting throughout the initial phases of the cancer continuum. Successful studies will begin with early intervention in the clinical setting, with increasing intensity as survivors transition to the recovery phase.

Impact of a workplace 'sit less, move more' program on efficiency-related outcomes of office employees

Background

Few studies have examined the impact of ‘sit less, move more’ interventions on workplace performance. This study assessed the short and mid-term impacts of and patterns of change within, a 19-week workplace web-based intervention (Walk@WorkSpain; W@WS; 2010–11) on employees´ presenteeism, mental well-being and lost work performance.

Methods

A site randomised control trial recruited employees at six Spanish university campuses (n = 264; 42 ± 10 years; 171 female), assigned by worksite and campus to an Intervention (IG; used W@WS; n = 129; 87 female) or an active Comparison group (A-CG; pedometer, paper diary and self-reported sitting time; n = 135; 84 female). A linear mixed model assessed changes between the baseline, ramping (8 weeks), maintenance (11 weeks) and follow-up (two months) phases for the IG versus A-CG on (i) % of lost work productivity (Work Limitations Questionnaire; WLQ); (ii) three scales for presenteeism (WLQ) assessing difficulty meeting scheduling demands (Time), performing cognitive and inter-personal tasks (Mental-Interpersonal) and decrements in meeting the quantity, quality and timeliness of completed work (Output); and (iii) mental well-being (Warwick-Edinburgh Mental Well-being Scale). T-tests assessed differences between groups for changes on the main outcomes. In the IG, a multivariate logistic regression model identified patterns of response according to baseline socio-demographic variables, physical activity and sitting time.

Results

There was a significant 2 (group) × 2 (program time points) interaction for the Time (F [3]=8.69, p = 0.005), Mental-Interpersonal (F [3]=10.01, p = 0.0185), Output scales for presenteeism (F [3]=8.56, p = 0.0357), and for % of lost work performance (F [3]=10.31, p = 0.0161). Presenteeism and lost performance rose significantly in both groups across all study time points; after baseline performance was consistently better in the IG than in the A-CG. Better performance was linked to employees being more active (Time, p = 0.041) and younger (Mental-interpersonal, p = 0.057; Output, p = 0.017). Higher total sitting time during nonworking days (Mental-interpersonal, p = 0.019) and lower sitting time during workdays (WLQ Index, p = 0.013) also improved performance.

Conclusion

Versus an active comparison condition, a ‘sit less, move more` workplace intervention effectively reduced an array of markers of lost workday productivity.

Trial registration

NCT02960750; Date of registration: 07/11/2016.

Replacing sedentary time with sleep, light, or moderate-to-vigorous physical activity: effects on self-regulation and executive functioning

Recent attention has highlighted the importance of reducing sedentary time for maintaining health and quality of life. However, it is unclear how changing sedentary behavior may influence executive functions and self-regulatory strategy use, which are vital for the long-term maintenance of a health behavior regimen. The purpose of this cross-sectional study is to examine the estimated self-regulatory and executive functioning effects of substituting 30 min of sedentary behavior with 30 min of light activity, moderate-to-vigorous physical activity (MVPA), or sleep in a sample of older adults. This study reports baseline data collected from low-active healthy older adults (N = 247, mean age 65.4 ± 4.6 years) recruited to participate in a 6 month randomized controlled exercise trial examining the effects of various modes of exercise on brain health and function. Each participant completed assessments of physical activity self-regulatory strategy use (i.e., self-monitoring, goal-setting, social support, reinforcement, time management, and relapse prevention) and executive functioning. Physical activity and sedentary behaviors were measured using accelerometers during waking hours for seven consecutive days at each time point. Isotemporal substitution analyses were conducted to examine the effect on self-regulation and executive functioning should an individual substitute sedentary time with light activity, MVPA, or sleep. The substitution of sedentary time with both sleep and MVPA influenced both self-regulatory strategy use and executive functioning. Sleep was associated with greater self-monitoring (B = .23, p = .02), goal-setting (B = .32, p < .01), and social support (B = .18, p = .01) behaviors. Substitution of sedentary time with MVPA was associated with higher accuracy on 2-item (B = .03, p = .01) and 3-item (B = .02, p = .04) spatial working memory tasks, and with faster reaction times on single (B = -23.12, p = .03) and mixed-repeated task-switching blocks (B = -27.06, p = .04). Substitution of sedentary time with sleep was associated with marginally faster reaction time on mixed-repeated task-switching blocks (B = -12.20, p = .07) and faster reaction time on mixed-switch blocks (B = 17.21, p = .05), as well as reduced global reaction time switch cost (B = -16.86, p = .01). Substitution for light intensity physical activity did not produce significant effects. By replacing sedentary time with sleep and MVPA, individuals may bolster several important domains of self-regulatory behavior and executive functioning. This has important implications for the design of long-lasting health behavior interventions. Trial Registration clinicaltrials.gov identifier NCT00438347.

Sedentary behaviour is associated with increased long-term cardiovascular risk in patients with rheumatoid arthritis independently of moderate-to-vigorous physical activity

BACKGROUND

Rheumatoid Arthritis (RA) is associated with an increased risk of cardiovascular disease (CVD). The physical dysfunction symptomatic of RA means people living with this disease spend large periods of the day sedentary, which may further elevate their risk of CVD. The primary aim of this study was to investigate relationships between objectively assessed sedentary behaviour patterns and light physical activity (LPA) with 10-year risk of CVD. Secondary aims were to explore the role of sedentary behaviour patterns and LPA for individual CVD risk factors and functional disability in RA. The extent to which associations were independent of moderate-to-vigorous physical activity (MVPA) engagement was also examined.

METHODS

Baseline data from a subsample of participants recruited to the Physical Activity in Rheumatoid Arthritis (PARA) study were used to answer current research questions. Sixty-one patients with RA (mean age (± SD) = 54.92 ± 12.39 years) provided a fasted blood sample and underwent physical assessments to evaluate factors associated with their cardiovascular health. Sedentary behaviour patterns (sedentary time, sedentary bouts, sedentary breaks), LPA and MVPA were measured via 7-days of accelerometry. Ten-year CVD risk was computed (Q-risk-score2), and functional disability determined via questionnaire.

RESULTS

Regressions revealed significant positive associations between sedentary time and the number of sedentary bouts per day ≥20 min with 10-year CVD risk, with the reverse true for LPA participation. Associations were independent of MVPA engagement.

CONCLUSIONS

Promoting LPA participation and restricting sedentary bouts to <20 min may attenuate long-term CVD risk in RA, independent of MVPA engagement.

TRIAL REGISTRATION

ISRCTN04121489 (retrospectively registered 19/10/2012).

Examining sedentary time as a risk factor for cardiometabolic diseases and their markers in South Asian adults: a systematic review

OBJECTIVES

The objective was to systematically review the literature to determine whether sedentary time was associated with cardiometabolic diseases and their risk factors among South Asian adults.

METHODS

Six electronic databases were searched to identify all studies that examined the association between sedentary time and cardiometabolic diseases (e.g., diabetes, cardiovascular disease) and their risk factors [e.g., body mass index (BMI), waist circumference (WC), lipids, blood pressure (BP), glucose] among South Asian adults. Two independent reviewers performed abstract/full-text screening, data abstraction, and quality assessments.

RESULTS

Searching identified 1757 potential articles; 22 were used in the analysis. Greater sedentary time was associated with an increased likelihood of diabetes (n = 5), higher BMI (n = 13), WC (n = 3), BP (n = 2), and glucose (n = 4). Thirteen out of 22 studies were of higher quality.

CONCLUSION

Results identified a trend whereby greater sedentary time was associated with an increased risk for diabetes, and several other cardiometabolic risk factors among South Asian adults. High quality studies are needed to identify whether risk factors are independent of physical activity levels to inform culturally-specific interventions for South Asians.

Leisure-time physical activity, sedentary behaviors, sleep, and cardiometabolic risk factors at baseline in the PREDIMED-PLUS intervention trial: A cross-sectional analysis

Limited data exists on the interrelationships between physical activity (PA), sedentary behaviors and sleep concerning cardiometabolic risk factors in aged adults at high cardiovascular disease risk. Our aim was to examine independent and joint associations between time spent in leisure-time PA, sedentary behaviors and sleep on the prevalence of obesity, type 2 diabetes (T2D) and components of the metabolic syndrome (MetS) in Mediterranean individuals at high cardiovascular risk. Cross-sectional analyses were performed on baseline data from 5776 Spanish adults (aged 55-75y in men; 60-75y in women) with overweight/obesity and MetS, from October 2013 to October 2016, in the PREDIMED-PLUS trial. Employing multivariable-adjusted Cox regression with robust variance and constant time (given the cross-sectional design), higher prevalence of obesity, T2D and abdominal obesity as component of the MetS were associated with greater time in TV-viewing (Relative Risk, RR: 1.02, 95%CI: 1.01, 1.03; RR:1.04, 95%CI: 1.02, 1.06 and RR: 1.01 95%CI: 1.00, 1.02; respectively, all P < .01). Conversely, greater time in moderate-vigorous PA (MVPA) was associated with lower prevalence of obesity, T2D, abdominal obesity and low HDL-cholesterol (RR: 0.95, 95%CI: 0.93, 0.97; RR: 0.94, 95%CI: 0.89, 0.99; RR: 0.97, 95%CI: 0.96, 0.98; and RR: 0.95, 95%CI: 0.91, 0.99, respectively, all P < .05). For these outcomes, theoretically substituting 1-h/day of MVPA for 1-h/day TV-viewing was also significantly associated with lower prevalence (RR 0.91 to 0.97, all P < .05). Similar lower RR in these outcomes was observed when substituting 1-h/day of MVPA for 1-h/day of sleeping. Longer time watching TV and not meeting MVPA recommendations were jointly associated with higher RR of the prevalence of obesity and T2D. We concluded that, in senior individuals at high cardiovascular risk, greater time spent on MVPA and fewer on sedentary behaviors was inversely associated with prevalence of obesity, T2D, and some of the components of MetS.

Reallocating time to sleep, sedentary, and active behaviours in non-Hodgkin lymphoma survivors: associations with patient-reported outcomes

The purpose of this study was to examine potential effects of reallocating time between sleep, sedentary and active behaviours on fatigue symptoms and quality of life in a sample of non-Hodgkin lymphoma survivors. Non-Hodgkin lymphoma survivors identified from the Western Australian Cancer Registry (N = 149) (response rate = 36%; median age = 64 years) wore an Actigraph® GT3X+ accelerometer for 7 days and completed the Fatigue Scale, the Functional Assessment of Cancer Therapy-General and the Pittsburgh Sleep Quality Index. We used isotemporal substitution methods in linear regression models to examine the potential effects of reallocating time between sleep, sedentary and activity behaviours on fatigue and quality of life. Data collection was conducted in Western Australia in 2013. Significant differences were observed for fatigue symptoms when 30 min per day of bouted moderate-to-vigorous physical activity (10 min) was reallocated from 30 min per day of sleep (5.7 points, 95% CI = 1.8, 9.7), sedentary time bouts (20 min) (5.7 points, 95% CI = 1.6, 9.7), sedentary time non-bouts (5.1 points, 95% CI = 1.0, 9.3) or light intensity activity (5.5 points, 95% CI = 1.5, 9.5). Isotemporal substitution effects of reallocating sedentary time, sleep and light physical activity with bouted physical activity was significantly associated with fatigue, but not quality of life. Findings from the present study may aid in the development and delivery of health behaviour interventions that are more likely to influence the health outcome of interest.

The association between displacement of sedentary time and chronic musculoskeletal pain: an isotemporal substitution analysis

OBJECTIVES

Physical activity is an effective intervention for the prevention and management of chronic musculoskeletal pain (CMP). However, there is a lack of research to inform the intensity of physical activity that should be recommended. The aim of this study was to investigate the association between substituting 10minutes of sedentary time with either 10minutes of light physical activity (LPA) or moderate-to-vigorous physical activity (MVPA) and the CMP prevalence ratio.

DESIGN

Secondary Analysis (November 2015) of data from the Health Survey for England (2008).

PARTICIPANTS

2313 adults (≥16years).

MAIN OUTCOME MEASURES

Sedentary time, LPA and MVPA were measured using accelerometry. We used isotemporal models to quantify the prevalence ratio for CMP of replacing 10minutes of sedentary time with 10minutes of LPA or MVPA.

RESULTS

The prevalence of CMP in this sample was 17%. The unadjusted prevalence ratio was 0.99 (95% CI: 0.97 to 1.01) for LPA and 0.76 (0.70 to 0.84) for MVPA. The fully adjusted prevalence ratio was 1.01 (95% CI: 0.99 to 1.02) for LPA and 0.89 (0.82 to 0.96) for MVPA.

CONCLUSIONS

Substituting 10minutes of sedentary time with an equivalent period of LPA was not associated with a reduction in the prevalence ratio for CMP, whereas the equivalent replacement with MVPA showed a small protective relationship. Regarding CMP prevalence, physical activity intensity appears to be important, with MVPA rather than LPA showing a protective relationship. Prospective studies are needed to investigate causality.

Health associations with meeting new 24-hour movement guidelines for Canadian children and youth

The study objective was to examine whether meeting the new Canadian 24-hour movement guidelines was associated with health indicators in a representative sample of Canadian children and youth. Cross-sectional findings are based on 4157 (1239 fasting subsample) children and youth aged 6-17years from cycles 1-3 of the Canadian Health Measures Survey (CHMS). Sleep and screen time were subjectively measured while moderate- to vigorous-intensity physical activity (MVPA) was accelerometer-determined. Health indicators in the full sample (body mass index (BMI) z-scores, waist circumference, blood pressure, behavioral strengths and difficulties score (lower=better), and aerobic fitness) and fasting subsample (triglycerides, high-density lipoprotein (HDL)-cholesterol, C-reactive protein, and insulin) were measured. Meeting the overall guidelines was defined as: 9-11 hour/night (5-13years) or 8-10 hour/day (14-17years) of sleep, ≤2 hour/day of screen time, and ≥60 minute/day of MVPA. Compared to meeting all three recommendations, meeting none, one, and two recommendations were associated with a higher BMI z-score, waist circumference, and behavioral strengths and difficulties score and lower aerobic fitness in a gradient pattern (P_trend<0.05). Additionally, compared to meeting all three recommendations, meeting none and one recommendation were associated with higher systolic blood pressure and insulin (P_trend<0.05). Finally, compared to meeting all three recommendations, meeting no recommendations was associated with higher triglycerides and lower HDL-cholesterol (P_trend<0.05). Collectively, meeting more recommendations within the 24-hour movement guidelines was associated with better overall health. Since a small proportion (17%) of this representative sample was meeting the overall guidelines, efforts to promote adoption are needed.

Future directions in physical activity intervention research: expanding our focus to sedentary behaviors, technology, and dissemination

Despite the increased health risks of a sedentary lifestyle, only 49 % of American adults participate in physical activity (PA) at the recommended levels. In an effort to move the PA field forward, we briefly review three emerging areas of PA intervention research. First, new intervention research has focused on not only increasing PA but also on decreasing sedentary behavior. Researchers should utilize randomized controlled trials, common terminology, investigate which behaviors should replace sedentary behaviors, evaluate long-term outcomes, and focus across the lifespan. Second, technology has contributed to an increase in sedentary behavior but has also led to innovative PA interventions. PA technology research should focus on large randomized trials with evidence-based components, explore social networking and innovative apps, improve PA monitoring, consider the lifespan, and be grounded in theory. Finally, in an effort to maximize public health impact, dissemination efforts should address the RE-AIM model, health disparities, and intervention costs.

An intervention to reduce sitting and increase light-intensity physical activity at work: Design and rationale of the 'Stand & Move at Work' group randomized trial

BACKGROUND

American workers spend 70-80% of their time at work being sedentary. Traditional approaches to increase moderate-vigorous physical activity (MVPA) may be perceived to be harmful to productivity. Approaches that target reductions in sedentary behavior and/or increases in standing or light-intensity physical activity [LPA] may not interfere with productivity and may be more feasible to achieve through small changes accumulated throughout the workday METHODS/DESIGN: This group randomized trial (i.e., cluster randomized trial) will test the relative efficacy of two sedentary behavior focused interventions in 24 worksites across two states (N=720 workers). The MOVE+ intervention is a multilevel individual, social, environmental, and organizational intervention targeting increases in light-intensity physical activity in the workplace. The STAND+ intervention is the MOVE+ intervention with the addition of the installation and use of sit-stand workstations to reduce sedentary behavior and enhance light-intensity physical activity opportunities. Our primary outcome will be objectively-measured changes in sedentary behavior and light-intensity physical activity over 12months, with additional process measures at 3months and longer-term sustainability outcomes at 24months. Our secondary outcomes will be a clustered cardiometabolic risk score (comprised of fasting glucose, insulin, triglycerides, HDL-cholesterol, and blood pressure), workplace productivity, and job satisfaction DISCUSSION: This study will determine the efficacy of a multi-level workplace intervention (including the use of a sit-stand workstation) to reduce sedentary behavior and increase LPA and concomitant impact on cardiometabolic health, workplace productivity, and satisfaction.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02566317 (date of registration: 10/1/2015).

Interactions between sleep, movement and other non-movement behaviours in the pathogenesis of childhood obesity

Research examining the health effects of physical activity, sedentary behaviour and sleep on different health outcomes has largely been conducted independently or in isolation of the other behaviours. However, the fact that time is finite (i.e. 24 h) suggests that the debate on whether or not the influence of a single behaviour is independent of another one is conceptually incorrect. Time spent in one behaviour should naturally depend on the composition of the rest of the day. Recent evidence using more appropriate analytical approaches to deal with this methodological issue shows that the combination of sleep, movement and non-movement behaviours matters and all components of the 24-h movement continuum should be targeted to enhance health and prevent childhood obesity. The objective of this review is to discuss research investigating how combinations of physical activity, sedentary behaviour and sleep are related to childhood obesity. Emerging statistical approaches (e.g. compositional data analysis) that can provide a good understanding of the best 'cocktail' of behaviours associated with lower adiposity and improved health are also discussed. Finally, future research directions are provided. Collectively, it becomes clearer that guidelines and public health interventions should target all movement behaviours synergistically to optimize health of children and youth around the world.

Canadian 24-Hour Movement Guidelines for Children and Youth: An Integration of Physical Activity, Sedentary Behaviour, and Sleep

Leaders from the Canadian Society for Exercise Physiology convened representatives of national organizations, content experts, methodologists, stakeholders, and end-users who followed rigorous and transparent guideline development procedures to create the Canadian 24-Hour Movement Guidelines for Children and Youth: An Integration of Physical Activity, Sedentary Behaviour, and Sleep. These novel guidelines for children and youth aged 5-17 years respect the natural and intuitive integration of movement behaviours across the whole day (24-h period). The development process was guided by the Appraisal of Guidelines for Research Evaluation (AGREE) II instrument and systematic reviews of evidence informing the guidelines were assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Four systematic reviews (physical activity, sedentary behaviour, sleep, integrated behaviours) examining the relationships between and among movement behaviours and several health indicators were completed and interpreted by expert consensus. Complementary compositional analyses were performed using Canadian Health Measures Survey data to examine the relationships between movement behaviours and health indicators. A stakeholder survey was employed (n = 590) and 28 focus groups/stakeholder interviews (n = 104) were completed to gather feedback on draft guidelines. Following an introductory preamble, the guidelines provide evidence-informed recommendations for a healthy day (24 h), comprising a combination of sleep, sedentary behaviours, light-, moderate-, and vigorous-intensity physical activity. Proactive dissemination, promotion, implementation, and evaluation plans have been prepared in an effort to optimize uptake and activation of the new guidelines. Future research should consider the integrated relationships among movement behaviours, and similar integrated guidelines for other age groups should be developed.

Associations of reallocating sitting time into standing or stepping with glucose, insulin and insulin sensitivity: a cross-sectional analysis of adults at risk of type 2 diabetes

OBJECTIVE

To quantify associations between sitting time and glucose, insulin and insulin sensitivity by considering reallocation of time into standing or stepping.

DESIGN

Cross-sectional.

SETTING

Leicestershire, UK, 2013.

PARTICIPANTS

Adults aged 30-75 years at high risk of impaired glucose regulation (IGR) or type 2 diabetes. 435 adults (age 66.8±7.4 years; 61.7% male; 89.2% white European) were included.

METHODS

Participants wore an activPAL3 monitor 24 hours/day for 7 days to capture time spent sitting, standing and stepping. Fasting and 2-hour postchallenge glucose and insulin were assessed; insulin sensitivity was calculated by Homeostasis Model Assessment of Insulin Secretion (HOMA-IS) and Matsuda-Insulin Sensitivity Index (Matsuda-ISI). Isotemporal substitution regression modelling was used to quantify associations of substituting 30 min of waking sitting time (accumulated in prolonged (≥30 min) or short (<30 min) bouts) for standing or stepping on glucose regulation and insulin sensitivity. Interaction terms were fitted to assess whether the associations with measures of glucose regulation and insulin sensitivity was modified by sex or IGR status.

RESULTS

After adjustment for confounders, including waist circumference, reallocation of prolonged sitting to short sitting time and to standing was associated with 4% lower fasting insulin and 4% higher HOMA-IS; reallocation of prolonged sitting to standing was also associated with a 5% higher Matsuda-ISI. Reallocation to stepping was associated with 5% lower 2-hour glucose, 7% lower fasting insulin, 13% lower 2-hour insulin and a 9% and 16% higher HOMA-IS and Matsuda-ISI, respectively. Reallocation of short sitting time to stepping was associated with 5% and 10% lower 2-hour glucose and 2-hour insulin and 12% higher Matsuda-ISI. Results were not modified by IGR status or sex.

CONCLUSIONS

Reallocating a small amount of short or prolonged sitting time with standing or stepping may improve 2-hour glucose, fasting and 2-hour insulin and insulin sensitivity. Findings should be confirmed through prospective and intervention research.

TRIAL REGISTRATION NUMBER

ISRCTN31392913, Post-results.

Physical Activity, Energy Expenditure, Nutritional Habits, Quality of Sleep and Stress Levels in Shift-Working Health Care Personnel

BACKGROUND

Among health care personnel working regular hours or rotating shifts can affect parameters of general health and nutrition. We have investigated physical activity, sleep quality, metabolic activity and stress levels in health care workers from both groups.

METHODS

We prospectively recruited 46 volunteer participants from the workforce of a University Medical Department of which 23 worked in rotating shifts (all nursing) and 21 non-shift regular hours (10 nursing, 13 clerical staff). All were investigated over 7 days by multisensory accelerometer (SenseWear Bodymedia® armband) and kept a detailed food diary. Physical activity and resting energy expenditure (REE) were measured in metabolic equivalents of task (METs). Quality of sleep was assessed as Pittsburgh Sleeping Quality Index and stress load using the Trier Inventory for Chronic Stress questionnaire (TICS).

RESULTS

No significant differences were found for overall physical activity, steps per minute, time of exceeding the 3 METs level or sleep quality. A significant difference for physical activity during working hours was found between shift-workers vs. non-shift-workers (p<0.01) and for shift-working nurses (median = 2.1 METs SE = 0.1) vs. non-shift-working clerical personnel (median = 1.5 METs SE = 0.07, p<0.05). Non-shift-working nurses had a significantly lower REE than the other groups (p<0.05). The proportion of fat in the diet was significantly higher (p<0.05) in the office worker group (median = 42% SE = 1.2) whereas shift-working nurses consumed significantly more carbohydrates (median = 46% SE = 1.4) than clerical staff (median = 41% SE = 1.7). Stress assessment by TICS confirmed a significantly higher level of social overload in the shift working group (p<0.05).

CONCLUSION

In this prospective cohort study shift-working had no influence on overall physical activity. Lower physical activity during working hours appears to be compensated for during off-hours. Differences in nutritional habits and stress load warrant larger scale trials to determine the effect on implicit health-associated conditions.

Displacing Sedentary Time: Association with Cardiovascular Disease Prevalence

PURPOSE

Isotemporal substitution analysis offers new insights for public health but has only recently been applied to sedentary behavior research. We aimed to quantify associations between the substitution of 10 min of sedentary behavior with 10 min of light physical activity (LPA) or moderate-to-vigorous physical activity (MVPA) and the prevalence of cardiovascular disease (CVD). Age was also explored as a potential effect modifier.

METHODS

We completed a secondary analysis of data from 1477 adults from the Health Survey for England (2008). Sedentary time, LPA, and MVPA were measured using accelerometry. We applied isotemporal models to quantify the relationship with CVD prevalence of replacing 10 min of sedentary time with equivalent amounts of LPA or MVPA. Prevalence risk ratios (RR) with 95% confidence intervals (CI) are presented, adjusted for covariates. The role of age as an effect modifier was explored via age-MVPA and age-LPA interactions. CVD was defined as per the International Classification of Diseases.

RESULTS

The prevalence of CVD was 24%. The RR was 0.97 (95% CI, 0.96-0.99) for LPA and 0.88 (0.81-0.96) for MVPA. Substitution of approximately 50 min of LPA would be required for an association equivalent to 10 min of MVPA. The beneficial association of MVPA was attenuated with age, with a decrease in the relative risk reduction of approximately 7% per decade.

CONCLUSIONS

Isotemporal substitution of sedentary time with LPA was associated with a trivial relative risk reduction for CVD, whereas the equivalent replacement with MVPA had a small beneficial relationship. With respect to CVD prevalence, MVPA might become decreasingly important in older individuals. Prospective studies are needed to investigate causality.

Using Sit-to-Stand Workstations in Offices: Is There a Compensation Effect?

PURPOSE

Sit-to-stand workstations are becoming common in modern offices and are increasingly being implemented in sedentary behavior interventions. The purpose of this study was to examine whether the introduction of such a workstation among office workers leads to reductions in sitting during working hours, and whether office workers compensate for any reduction in sitting at work by increasing sedentary time and decreasing physical activity (PA) outside work.

METHODS

Office workers (n = 40; 55% female) were given a WorkFit-S, sit-to-stand workstation for 3 months. Participants completed assessments at baseline (before workstation installation), 1 wk and 6 wk after the introduction of the workstation, and again at 3 months (postintervention). Posture and PA were assessed using the activPAL inclinometer and ActiGraph GT3X+ accelerometer, which participants wore for 7 d during each measurement phase.

RESULTS

Compared with baseline, the proportion of time spent sitting significantly decreased (75% ± 13% vs 52% ± 16% to 56% ± 13%), and time spent standing and in light activity significantly increased (standing: 19% ± 12% vs 32% ± 12% to 37% ± 15%, light PA: 14% ± 4% vs 16% ± 5%) during working hours at all follow-up assessments. However, compared with baseline, the proportion of time spent sitting significantly increased (60% ± 11% vs 66% ± 12% to 68% ± 12%) and light activity significantly decreased (21% ± 5% vs 19% ± 5%) during nonworking hours across the follow-up measurements. No differences were seen in moderate-to-vigorous activity during nonworking hours throughout the study.

CONCLUSION

The findings suggest that introducing a sit-to-stand workstation can significantly reduce sedentary time and increase light activity levels during working hours. However, these changes were compensated for by reducing activity and increasing sitting outside of working hours. An intervention of a sit-to-stand workstation should be accompanied by an intervention outside of working hours to limit behavior compensation.

Physical Activity Contributes to Several Sleep-Cardiometabolic Health Relationships

PURPOSE

To estimate the contribution of accelerometer-derived physical activity to the relationship between sleep and cardiometabolic health.

METHODS

Data from the 2005 to 2006 US National Health and Nutritional Examination Survey were used (N = 1226; 20 years+). Metabolic syndrome (MetS) was defined by the Joint Interim Statement, and sleep quality and quantity by the Sleep Disorders Questionnaire. Physical activity intensities were defined by activity thresholds (counts per minute) as sedentary activity (0-99), light intensity (100-759), lifestyle activity (760-2019), moderate intensity (2020-5996), and vigorous intensity (≥5999). Outcomes were MetS, number of MetS components, waist circumference (WC), systolic and diastolic blood pressure (BP), triglycerides, HDL-cholesterol, fasting plasma glucose, and fasting insulin concentration. The bootstrap method was used to estimate the amount of mediation or contribution of activity intensities (ab) to the sleep-cardiometabolic health relationships, which were quantified as large (≥0.25) or moderate (≥0.09).

RESULTS

Lifestyle activity level contributes to several sleep duration and cardiometabolic health relationships, most notably for WC (ab: 0.28), systolic BP (0.39), and fasting insulin concentration (0.85). While moderate intensity and lifestyle activity intensities were large contributors to the sleep quality-fasting insulin concentration relationship (0.47 and 0.48, respectively), light intensity activity only moderately contributed to the relationship between sleep duration and quality with abdominal obesity (0.15).

CONCLUSION

Lifestyle and moderate intensity physical activity have a large effect on the relationship between sleep and cardiometabolic health, including WC, BP, and fasting insulin concentration. Appropriate sleep hygiene, in combination with regular physical activity should be considered mutually beneficial targets for cardiometabolic health.

Accelerometer-measured dose-response for physical activity, sedentary time, and mortality in US adults

BACKGROUND

Moderate-to-vigorous-intensity physical activity is recommended to maintain and improve health, but the mortality benefits of light activity and risk for sedentary time remain uncertain.

OBJECTIVES

Using accelerometer-based measures, we 1) described the mortality dose-response for sedentary time and light- and moderate-to-vigorous-intensity activity using restricted cubic splines, and 2) estimated the mortality benefits associated with replacing sedentary time with physical activity, accounting for total activity.

DESIGN

US adults (n = 4840) from NHANES (2003-2006) wore an accelerometer for ≤7 d and were followed prospectively for mortality. Proportional hazards models were used to estimate adjusted HRs and 95% CIs for mortality associations with time spent sedentary and in light- and moderate-to-vigorous-intensity physical activity. Splines were used to graphically present behavior-mortality relation. Isotemporal models estimated replacement associations for sedentary time, and separate models were fit for low- (<5.8 h total activity/d) and high-active participants to account for nonlinear associations.

RESULTS

Over a mean of 6.6 y, 700 deaths occurred. Compared with less-sedentary adults (6 sedentary h/d), those who spent 10 sedentary h/d had 29% greater risk (HR: 1.29; 95% CI: 1.1, 1.5). Compared with those who did less light activity (3 h/d), those who did 5 h of light activity/d had 23% lower risk (HR: 0.77; 95% CI: 0.6, 1.0). There was no association with mortality for sedentary time or light or moderate-to-vigorous activity in highly active adults. In less-active adults, replacing 1 h of sedentary time with either light- or moderate-to-vigorous-intensity activity was associated with 18% and 42% lower mortality, respectively.

CONCLUSIONS

Health promotion efforts for physical activity have mostly focused on moderate-to-vigorous activity. However, our findings derived from accelerometer-based measurements suggest that increasing light-intensity activity and reducing sedentary time are also important, particularly for inactive adults.

Sitting Less and Moving More: Improved Glycaemic Control for Type 2 Diabetes Prevention and Management

Epidemiological evidence indicates that excessive time spent in sedentary behaviours (too much sitting) is associated with an increased risk of type 2 diabetes (T2D). Here, we highlight findings of experimental studies corroborating and extending the epidemiological evidence and showing the potential benefits for T2D of reducing and breaking up sitting time across the whole day. We also discuss future research opportunities and consider emerging implications for T2D prevention and management. This new evidence is stimulating an expansion of diabetes-related physical activity guidelines-suggesting that in addition to moderate-vigorous physical activity, reducing and regularly interrupting prolonged sitting time is likely to have important and varied benefits across the spectrum of diabetes risk.

Reallocating Time to Sleep, Sedentary Time, or Physical Activity: Associations with Waist Circumference and Body Mass Index in Breast Cancer Survivors

BACKGROUND

Moderate-to-vigorous intensity physical activity (MVPA) is inversely associated with waist circumference and body mass index (BMI) among breast cancer survivors. Limited research has focused on behaviors that account for larger portions of the day [sleep, sedentary time, and light-intensity physical activity (LPA)]. We investigated the interdependent associations of self-reported sleep, objectively assessed prolonged and short bouts of sedentary time, total LPA, and total MVPA with waist circumference and BMI.

METHODS

A cross-sectional sample of breast cancer survivors (N = 256, mean age = 60 years; mean time since diagnosis = 3 years) wore an Actigraph GT3X+ accelerometer during waking hours for 7 days. Participants completed the Pittsburgh Sleep Quality Index and self-reported their waist circumference, height, and weight. An isotemporal substitution approach was used in linear regression models to explore the associations of reallocating time to sleep, sedentary and active behaviors on waist circumference, and BMI, after adjusting for potential confounders.

RESULTS

Reallocating 30 minutes to MVPA was significantly associated with lower waist circumference when allocated from sleep (-2.50 cm), prolonged sedentary time (-2.51 cm), or LPA (-2.71 cm). Reallocating 30 minutes of prolonged sedentary time to nonprolonged sedentary time was significantly associated with lower waist circumference (-0.94 cm). Similar results were observed for BMI.

CONCLUSIONS

Reallocating 30 minutes to MVPA was associated with significantly lower waist circumference and BMI, as was reallocating 30 minutes of prolonged sedentary time to 30 minutes of nonprolonged sedentary time.

IMPACT

Increasing MVPA levels and decreasing time spent in prolonged, unbroken sedentary bouts may be avenues for improving body composition in this population. Cancer Epidemiol Biomarkers Prev; 26(2); 254-60. ©2016 AACR.

Physical activity among older Chinese adults living in urban and rural areas: A review

With an increase in rural-to-urban migration, a rapidly aging population, and the rising risk of developing noncommunicable diseases in China, it is important to understand the epidemiology of physical activity (PA) and health in the context of disease prevention and population health. Despite its public health importance, there is a significant lack of knowledge about PA in older Chinese adults that may hamper primary prevention efforts of health promotion in an increasingly aging population. To fill this gap, this article presents a narrative review of PA in the older Chinese adult population with a special focus on residential settings (i.e., urban and rural). Using existing studies, the review examines overall PA patterns and their correlates and discusses public health implications and future research. Although there are some preliminary indications of urban and rural differences in PA in the aging population in China, continued research efforts are needed to facilitate primary prevention efforts aimed at reducing noncommunicable diseases and promoting an active lifestyle among the largest population of older people in the world.

BeWell24: development and process evaluation of a smartphone "app" to improve sleep, sedentary, and active behaviors in US Veterans with increased metabolic risk

Lifestyle behaviors across the 24-h spectrum (i.e., sleep, sedentary, and active behaviors) drive metabolic risk. We describe the development and process evaluation of BeWell24, a multicomponent smartphone application (or "app") that targets behavior change in these interdependent behaviors. A community-embedded iterative design framework was used to develop the app. An 8-week multiphase optimization strategy design study was used to test the initial efficacy of the sleep, sedentary, and exercise components of the app. Process evaluation outcomes included objectively measured app usage statistics (e.g., minutes of usage, self-monitoring patterns), user experience interviews, and satisfaction ratings. Participants (N = 26) logged approximately 60 % of their sleep, sedentary, and exercise behaviors, which took 3-4 min/day to complete. Usage of the sleep and sedentary components peaked at week 2 and remained high throughout the intervention. Exercise component use was low. User experiences were mixed, and overall satisfaction was modest.

Sedentary Behavior and Cardiovascular Morbidity and Mortality: A Science Advisory From the American Heart Association

Epidemiological evidence is accumulating that indicates greater time spent in sedentary behavior is associated with all-cause and cardiovascular morbidity and mortality in adults such that some countries have disseminated broad guidelines that recommend minimizing sedentary behaviors. Research examining the possible deleterious consequences of excess sedentary behavior is rapidly evolving, with the epidemiology-based literature ahead of potential biological mechanisms that might explain the observed associations. This American Heart Association science advisory reviews the current evidence on sedentary behavior in terms of assessment methods, population prevalence, determinants, associations with cardiovascular disease incidence and mortality, potential underlying mechanisms, and interventions. Recommendations for future research on this emerging cardiovascular health topic are included. Further evidence is required to better inform public health interventions and future quantitative guidelines on sedentary behavior and cardiovascular health outcomes.

Too much sitting and all-cause mortality: is there a causal link?

Background

Sedentary behaviours (time spent sitting, with low energy expenditure) are associated with deleterious health outcomes, including all-cause mortality. Whether this association can be considered causal has yet to be established.

Using systematic reviews and primary studies from those reviews, we drew upon Bradford Hill’s criteria to consider the likelihood that sedentary behaviour in epidemiological studies is likely to be causally related to all-cause (premature) mortality.

Methods

Searches for systematic reviews on sedentary behaviours and all-cause mortality yielded 386 records which, when judged against eligibility criteria, left eight reviews (addressing 17 primary studies) for analysis. Exposure measures included self-reported total sitting time, TV viewing time, and screen time. Studies included comparisons of a low-sedentary reference group with several higher sedentary categories, or compared the highest versus lowest sedentary behaviour groups. We employed four Bradford Hill criteria: strength of association, consistency, temporality, and dose–response. Evidence supporting causality at the level of each systematic review and primary study was judged using a traffic light system depicting green for causal evidence, amber for mixed or inconclusive evidence, and red for no evidence for causality (either evidence of no effect or no evidence reported).

Results

The eight systematic reviews showed evidence for consistency (7 green) and temporality (6 green), and some evidence for strength of association (4 green). There was no evidence for a dose–response relationship (5 red). Five reviews were rated green overall. Twelve (67 %) of the primary studies were rated green, with evidence for strength and temporality.

Conclusions

There is reasonable evidence for a likely causal relationship between sedentary behaviour and all-cause mortality based on the epidemiological criteria of strength of association, consistency of effect, and temporality.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3307-3) contains supplementary material, which is available to authorized users.

In-school versus out-of-school sedentary behavior patterns in U.S. children

Background

This study contributes to the literature by using accelerometers to describe sedentary behavior (SB) patterns in US children. The purpose of this study was to examine SB patterns in fifth-graders by specifically focusing on in-school versus out-of-school SB patterns to identify when (during the school day or outside of the school day) interventions should take place in order to decrease SB in children.

Methods

Data were collected from 206 fifth-graders (9–11 years old) in the Cherry Creek School District in metro Denver, Colorado (USA) during the spring of the 2010–2011 school year and fall of the 2011–2012 school year. Children wore Actical accelerometers continuously over an eight-day period. Data were analyzed using Wilcoxon rank tests, paired samples t-tests, and independent samples t-tests. Awake time was 6 AM–11 PM. We compared the percent of time spent in SB before school, during school, at recess/lunch and after school, as well as differences between boys and girls, and between children from low and high socioeconomic status schools. Children were classified as ‘non-sedentary’ or ‘sedentary’ if they participated in <360 min or ≥360 min per day of SB, respectively and were classified as ‘inactive’ or ‘active’ if they participated in <60 min or ≥ 60 min per day of MVPA, respectively.

Cross-tabs were used (and Fisher’s exact test) to identify the proportion of children in the following categories: 1) non-sedentary/inactive; 2) sedentary/inactive; 3) non-sedentary/active; and 4) sedentary/active. Statistical significance was set at p < 0.05.

Results

All children (boys and girls and children from low and high socioeconomic status schools) participated in significantly more SB outside of school hours versus during school hours and on weekend days compared to weekdays (p < 0.001). Girls participated in significantly more SB than boys during weekdays (p = 0.015). The majority of children (65.3 %) were classified as sedentary/active.

Conclusions

Given that children appear to be more sedentary during the weekend, where more opportunities to be physically active with the whole family can easily be implemented, future interventions should focus on time periods outside of school hours in order to decrease sedentary behavior and increase light physical activity in particular.

Rationale, design and protocol of a longitudinal study assessing the effect of total knee arthroplasty on habitual physical activity and sedentary behavior in adults with osteoarthritis

Background

Physical activity levels are decreased and sedentary behaviour levels are increased in patients with knee osteoarthritis (OA). However, previous studies have shown that following total knee arthroplasty (TKA), objectively measured physical activity levels do not change compared to before the surgery. Very few studies have objectively assessed sedentary behaviour following TKA. This study aims to assess patterns of objective habitual physical activity and sedentary behaviour in patients with knee OA and to determine whether these change following TKA.

Methods

Patients diagnosed with knee osteoarthritis and scheduled for unilateral primary total knee arthroplasty will be recruited from the Orthopaedic Division at the Charlotte Maxeke Johannesburg Academic Hospital. Eligible participants will have assessments completed one week before the scheduled arthroplasty, six weeks, and six months post-operatively. The primary outcomes are habitual physical activity and sedentary behaviour which will be measured using accelerometry (Actigraph GTX3+ and activPal monitors) at the specific time points. The secondary outcomes will be improvements in osteoarthritis-specific quality of life measures using the following questionnaires: Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee injury and Osteoarthritis Outcome Score (KOOS), Oxford Knee Score (OKS), Knee Society Clinical Rating System (KSS), UCLA activity index; subjective pain scores, and self reported sleep quality.

Discussion

The present study will contribute to the field of musculoskeletal health by providing a rich detailed description of the patterns of accumulation of physical activity and sedentary behaviour in patients with knee OA. These data will contribute to existing knowledge using an objective measurement for the assessment of functional ability after total knee arthroplasty. Although studies have used accelerometry to measure physical activity in knee OA patients, the data provided thus far have not delved into the detailed patterns of how and when physical activity is accumulated before and after TKA. Accurate assessment of physical activity is important for physical activity interventions that target special populations.

Trial registration

NCT02675062 (4 February 2016).

A comparison of work-related physical activity levels between inpatient and outpatient physical therapists: an observational cohort trial

Background

Physical therapists (PTs) work in a variety of healthcare settings with varied levels of physical activity demands placed on them. The purpose of this study is to compare the physical activity (PA) levels between PTs in inpatient versus outpatient environments for one work week using a cross-sectional design.

Methods

Sixty-one PTs (30 inpatient, 31 outpatient) wore a tri-axial accelerometer and inclinometer for one work-week. The number steps-per-day, PA intensities, energy expenditures and postural positions adopted during the work day were recorded.

Result

Significantly longer amounts of time spent sitting was found for inpatient PTs regardless of the significantly higher number of steps-per-day. Outpatient PTs had a higher number of breaks from sedentary activity with those breaks being longer than the inpatient PTs. The percentage of time spent performing moderate-vigorous PA approached significance implying more time was spent performing these types of activities for outpatient PTs. The energy expenditures between the two groups of PTs were not different.

Conclusion

This study compared the differences in physical activity levels between physical therapists who worked at inpatient versus outpatient environment as little is known about their activity levels. Inpatient physical therapists took more steps per day than outpatient physical therapists but the outpatient physical therapists were less sedentary and took more frequent and longer breaks from sedentary activities. The energy expenditures were similar between both types of therapists and this may be reflective of the gender and bodyweight differences between the groups that equalizes the energy expenditures. The findings of this study suggests that there are differences in the physical activity demands between inpatient and outpatient physical therapists. The results of this study may serve dual purposes: (1) employers may be able to more accurately describe the expected physical activity demands to future employees; (2) individuals tasked with preparing PTs to physically manage their work environment can outline training programs that are diverse based on the specific work environment of PTs.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-016-2119-y) contains supplementary material, which is available to authorized users.

The Potential Impact of Displacing Sedentary Time in Adults with Type 2 Diabetes

Purpose

Sedentary time, in particular, prolonged unbroken sedentary time, is detrimental to health and displaces time spent in either light or moderate intensity physical activity. This cross-sectional study aimed to identify the potential impact of reallocating time from sedentary behaviors to more active behaviors on measures of body composition and metabolic health in people with type 2 diabetes.

Methods

Participants were 519 adults with newly diagnosed type 2 diabetes who had been recruited to the Early Activity in Diabetes (Early ACTID) randomized controlled trial. Waist-worn accelerometers were used to obtain objective measurement of sedentary time, light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) at baseline alongside clinical measurements and fasting blood samples to determine cholesterol, triglycerides, HOMA-IR, and glucose. Isotemporal substitution modeling was performed to determine the potential impact of reallocating 30 min of sedentary time accumulated in a single bout (long bout) with 30 min of interrupted sedentary time, LPA, or MVPA.

Results

Sedentary time accounted for 65% of the waking day, of which 45% was accumulated in prolonged (≥30 min) bouts. Reallocation of 30 min of long-bout sedentary time with 30 min of short-bout sedentary time was associated with lower body mass index (BMI) (adjusted β, −0.60; 95% confidence interval [CI], −1.00, −0.21) and waist circumference (WC) (adjusted β, −1.16; 95% CI, −2.08, −0.25). Stronger effects were seen for LPA and MVPA. Reallocation of 30 min of long-bout sedentary time with LPA was associated with higher HDL-cholesterol (adjusted β, 0.02; 95% CI, 0.00–0.03 mmol·L⁻¹).

Conclusions

Encouraging adults with newly diagnosed type 2 diabetes to break up prolonged periods of sedentary time may be an effective strategy for improving body composition and metabolic health.

Associations of Low- and High-Intensity Light Activity with Cardiometabolic Biomarkers

PURPOSE

Light-intensity physical activity (LIPA) accounts for much of adults' waking hours (≈40%) and substantially contributes to overall daily energy expenditure. Encompassing activity behaviors of low intensity (standing with little movement) to those of higher intensity (slow walking), LIPA is ubiquitous, yet little is known about how associations with health may vary depending on its intensity. We examined the associations of objectively assessed LIPA (categorized as either low LIPA [LLPA] or high LIPA [HLPA]) and moderate- to vigorous-intensity activity with cardiometabolic risk biomarkers.

METHODS

Cardiometabolic biomarkers were measured in 4614 US adults (47 ± 17 yr) who participated in the 2003-2004 and 2005-2006 National Health and Nutrition Examination Survey cycles. Multiple linear regression analyses examined the associations of three accelerometer-derived physical activity (SD increment per day) intensity categories (LLPA, 100-761 counts per minute; HLPA, 762-1951 counts per minute; moderate-intensity physical activity [MPA], 1952-5724 counts per minute; vigorous-intensity physical activity [VPA], ≥5725 counts per minute) with cardiometabolic biomarkers, adjusting for potential sociodemographic, behavioral, and medical confounders.

RESULTS

All intensities of physical activity were beneficially associated with waist circumference, C-reactive protein, triglycerides, fasting insulin, β-cell function, and insulin sensitivity (P < 0.05); only some activity intensities showed significant associations with systolic blood pressure (LLPA), body mass index, HDL cholesterol, fasting glucose, and 2-h plasma glucose (HLPA, MPA, and VPA). Generally, effect size increased with intensity of physical activity. Overall, further adjustment for waist circumference attenuated associations with MPA and VPA to a greater extent than associations with LLPA and HLPA.

CONCLUSIONS

The cross-sectional findings provide novel evidence for the potential benefits of increasing both LLPA and HLPA. They further reinforce the established importance of moderate- to vigorous-intensity activity, the mainstay of public health recommendations.

What Is the Effect on Obesity Indicators from Replacing Prolonged Sedentary Time with Brief Sedentary Bouts, Standing and Different Types of Physical Activity during Working Days? A Cross-Sectional Accelerometer-Based Study among Blue-Collar Workers

Introduction

The aim of the study was to investigate if (a) substituting total sedentary time or long sedentary bouts with standing or various types of physical activity and (b) substituting long sedentary bouts with brief sedentary bouts; is associated with obesity indicators using a cross sectional isotemporal substitution approach among blue-collar workers.

Methods

A total of 692 workers from transportation, manufacturing and cleaning sectors wore an Actigraph GT3X+ accelerometer on the thigh for 1–4 working days. The sedentary (sit and lie), standing, walking, and moderate to vigorous physical activity (MVPA) time on working days was computed using validated Acti4 software. The total sedentary time and uninterrupted sedentary time spent in brief (≤5 mins), moderate (>5 and ≤30 mins), and long (>30mins) bouts, were determined for the whole day and during work and non-work time separately. The obesity indicators, BMI (kg/m²), waist circumference (cm) and fat percentage were objectively measured. Isotemporal substitution modelling was utilized to determine the linear association with obesity indicators of replacing 30 min of total sedentary time or long sedentary bouts with standing, walking or MVPA and separately replacing 30 min of long sedentary bouts with brief sedentary bouts.

Results

Workers [mean (standard deviation, SD); age = 45.1 (9.9) years, BMI = 27.5 (4.9) kg/m², %BF = 29.6 (9.5), waist circumference = 94.4 (13.0) cm] sat for 2.4 hours (~32% of the measured time, SD = 1.8 hours) across the day during work period and 5.5 hours (~62% of the measured time, SD = 1.5 hours) during non-work period. Most of the sedentary time was accrued in moderate bouts [work = 1.40 (SD = 1.09) hours] during work and in long bouts during non-work [2.7 (SD = 1.4) hours], while least in long sedentary bouts during work [work = 0.5 (SD = 0.9)] and in brief sedentary bouts [0.5 hours (SD = 0.3)] during non-work. Significant associations with all obesity indicators were found when 30 min of total sedentary time or long sedentary bouts were replaced with standing time (~1–2% lower) or MVPA (~4–9% lower) during whole day, work, and non-work periods. The exception was that a statistically significant association was not observed with any obesity indicator when replacing total sedentary time or long sedentary bouts with standing time during the work period. Significant beneficial associations were found when replacing the long sedentary bouts with brief sedentary bouts (~3–5% lower) during all domains.

Conclusion

Replacing total sedentary time and long sedentary bouts, respectively, not only with MVPA but also standing time appears to be beneficially associated with obesity indicators among blue-collar workers. Additionally, replacing long sedentary bouts with brief sedentary bouts was also beneficially associated with obesity indicators. Studies using prospective design are needed to confirm the findings.

Sedentary behaviour in people with multiple sclerosis: Is it time to stand up against MS?

Historically, people with multiple sclerosis (MS) have been considered sedentary, although the actual scientific study of sedentary behaviour in MS did not originate until 2011. Sedentary behaviour, which is conceptually distinct from physical inactivity, is defined as any waking activity characterised by an energy expenditure ⩽ 1.5 metabolic equivalents and in a sitting or reclining posture. In the general population, the volume of sitting time is associated with increased risks of morbidity and mortality, independent of physical activity, and has been suggested to carry a greater risk of mortality than smoking behaviour. There are many symptoms of MS (e.g. mobility disability and fatigue) that could increase the prevalence of sedentary behaviour, and sedentary behaviour may have considerable implications for the development of comorbid conditions prevalent in MS. This review provides a summary of the rates, correlates, consequences and interventions attempting to reduce sedentary behaviour in MS. We provide a research agenda that guides future research on sedentary behaviour in MS. This paper provides a clarion call that it is time to 'stand up against MS'.

Modeling how substitution of sedentary behavior with standing or physical activity is associated with health-related quality of life in colorectal cancer survivors

PURPOSE

Previous research indicates that sedentary behavior is unfavorably associated with health-related quality of life (HRQoL) of colorectal cancer (CRC) survivors. Using isotemporal substitution modeling, we studied how substituting sedentary behavior with standing or physical activity was associated with HRQoL in CRC survivors, 2-10 years post-diagnosis.

METHODS

A cross-sectional study was conducted in stage I-III CRC survivors (n = 145) diagnosed at Maastricht University Medical Center+, the Netherlands (2002-2010). Sedentary, standing, and physical activity time were measured by the thigh-mounted MOX activity monitor. HRQoL outcomes comprised global quality of life, physical, role, and social functioning, and disability (scales: 0-100), fatigue (20-140), and depression and anxiety (0-21). Isotemporal substitution modeling was applied to analyze associations with HRQoL of substituting sedentary time with equal time in standing or physical activity.

RESULTS

On average, participants spent 10.2 h/day sedentary (SD, 1.7), 3.4 h/day standing (1.3), and 1.7 h/day in physical activity (0.8). In confounder-adjusted isotemporal models, substituting sedentary time with standing or with physical activity was associated with significantly better physical functioning (regression coefficient [β], i.e., difference in outcome score per 1 h/day of sedentary time substituted with standing or physical activity, 3.1; 95% confidence interval [CI] 0.5, 5.7; and 5.6; 0.7, 10.6, respectively). Substituting sedentary time with standing was also associated with significantly lower disability (β, -3.0; 95% CI -4.9, -1.1) and fatigue (-4.0; -7.6, -0.3).

CONCLUSIONS

Our results suggest that substituting sedentary behavior with standing or physical activity may be beneficially associated with certain HRQoL outcomes in CRC survivors. Prospective studies are warranted to confirm whether actual substitution of sedentary behavior with these activities may improve HRQoL in CRC survivors.

Objectively measured patterns of sedentary time and physical activity in young adults of the Raine study cohort

Background

To provide a detailed description of young adults’ sedentary time and physical activity.

Methods

384 young women and 389 young men aged 22.1 ± 0.6 years, all participants in the 22 year old follow-up of the Raine Study pregnancy cohort, wore Actigraph GT3X+ monitors on the hip for 24 h/day over a one-week period for at least one ‘valid’ day (≥10 h of waking wear time). Each minute epoch was classified as sedentary, light, moderate or vigorous intensity using 100 count and Freedson cut-points. Mixed models assessed hourly and daily variation; t-tests assessed gender differences.

Results

The average (mean ± SD) waking wear time was 15.0 ± 1.6 h/day, of which 61.4 ± 10.1 % was spent sedentary, 34.6 ± 9.1 % in light-, 3.7 ± 5.3 % in moderate- and, 0.3 ± 0.6 % in vigorous-intensity activity. Average time spent in moderate to vigorous activity (MVPA) was 36.2 ± 27.5 min/day. Relative to men, women had higher sedentary time, but also higher vigorous activity time. The ‘usual’ bout duration of sedentary time was 11.8 ± 4.5 min in women and 11.7 ± 5.2 min in men. By contrast, other activities were accumulated in shorter bout durations. There was large variation by hour of the day and by day of the week in both sedentary time and MVPA. Evenings and Sundays through Wednesdays tended to be particularly sedentary and/or inactive.

Conclusion

For these young adults, much of the waking day was spent sedentary and many participants were physically inactive (low levels of MVPA). We provide novel evidence on the time for which activities were performed and on the time periods when young adults were more sedentary and/or less active. With high sedentary time and low MVPA, young adults may be at risk for the life-course sequelae of these behaviours.

Electronic supplementary material

The online version of this article (doi:10.1186/s12966-016-0363-0) contains supplementary material, which is available to authorized users.

Does duration of physical activity bouts matter for adiposity and metabolic syndrome? A cross-sectional study of older British men

Background

Older adults have low physical activity(PA) and high sedentary behaviour(SB) levels. We investigate how total volume and specific patterns of moderate to vigorous PA(MVPA), light PA(LPA) and SB are related to adiposity and metabolic syndrome (MS). Then, with reference to physical activity guidelines which encourage MVPA in bouts > =10 min and avoiding “long” sedentary bouts, we investigate whether accumulating PA and SB in bouts of different defined durations are differently associated with these outcomes.

Methods

Cross-sectional study of men (71–91 years) recruited in UK primary care centres. Nurses made physical measures (weight, height, bio-impedance, blood pressure) and took fasting blood samples. 1528/3137 (49 %) surviving men had ≥3 valid days (≥600 min) accelerometer data. 450 men with pre-existing chronic disease were excluded. 1009/1078 (93.6 %) had complete covariate data.

Results

Men (n = 1009, mean age 78.5(SD 4.7) years) spent 612(SD 83), 202(SD 64) and 42(SD 33) minutes in SB, LIPA and MVPA respectively. Each additional 30 min/day of SB and MVPA were associated with 0.32 (95 % CI 0.23, 0.40)Kg/m² higher Body Mass Index (BMI) and −0.72(−0.93, −0.51) lower BMI Kg/m² respectively. Patterns for waist circumference (WC), fat mass index (FMI), fasting insulin and MS were similar. MVPA in bouts lasting <10 min or ≥10 min duration were not associated differently with outcomes. In models adjusted for total MVPA, each minute accumulated in SB bouts lasting 1–15 min was associated with lower BMI −0.012 kg/m², WC −0.029 cm, and OR 0.989 for MS (all p < 0.05), and coefficients for LPA bouts 1–9 min were very similar in separate models adjusted for total MVPA. Minutes accumulated in SB bouts 1–15 min and LPA bouts 1–9 min were correlated, r = 0.62.

Conclusions

Objectively measured MVPA, LPA and SB were all associated with lower adiposity and metabolic risk. The beneficial associations of LPA are encouraging for older adults for whom initiating MVPA and maintaining bouts lasting ≥10 min may be particularly challenging. Findings that short bouts of LPA (1–9 min) and SB (1–15 min), but that all MVPA, not just MVPA accumulated in bouts ≥10 min were associated with lower adiposity and better metabolic health could help refine older adult PA guidelines.

Behavioral Periodicity Detection from 24 h Wrist Accelerometry and Associations with Cardiometabolic Risk and Health-Related Quality of Life

Periodicities (repeating patterns) are observed in many human behaviors. Their strength may capture untapped patterns that incorporate sleep, sedentary, and active behaviors into a single metric indicative of better health. We present a framework to detect periodicities from longitudinal wrist-worn accelerometry data. GENEActiv accelerometer data were collected from 20 participants (17 men, 3 women, aged 35–65) continuously for 64.4 ± 26.2 (range: 13.9 to 102.0) consecutive days. Cardiometabolic risk biomarkers and health-related quality of life metrics were assessed at baseline. Periodograms were constructed to determine patterns emergent from the accelerometer data. Periodicity strength was calculated using circular autocorrelations for time-lagged windows. The most notable periodicity was at 24 h, indicating a circadian rest-activity cycle; however, its strength varied significantly across participants. Periodicity strength was most consistently associated with LDL-cholesterol (r's = 0.40–0.79, P's < 0.05) and triglycerides (r's = 0.68–0.86, P's < 0.05) but also associated with hs-CRP and health-related quality of life, even after adjusting for demographics and self-rated physical activity and insomnia symptoms. Our framework demonstrates a new method for characterizing behavior patterns longitudinally which captures relationships between 24 h accelerometry data and health outcomes.

Free-living cross-comparison of two wearable monitors for sleep and physical activity in healthy young adults

There is a growing need for free-living monitoring of the full 24 h spectrum of behaviors with a single or integrated set of sensors. The validity of field standard wearable monitors in sleep and physical activity have yet to be assessed for the complementary behavior in the context of 24 h continuous monitoring. We conducted a free-living comparison study of the Actigraph GT3X+ (GT3X+) to assess sleep parameters as compared with the Actiwatch-64 (AW-64) and concurrently, the AW-64 to assess sedentary and physical activity behaviors as compared with the GT3X+. Thirty young adults (15 female, 19.2±0.86 years) wore both monitors for 3 consecutive days and 2 consecutive nights. Agreement of sleep, sedentary, and physical activity metrics were evaluated using analyses of variance, intraclass correlation coefficients, Bland-Altman plots with associated confidence limits, mean absolute percentage of errors and equivalence tests. For sleep, the GT3X+ showed high agreement for total sleep time and sleep efficiency, but underestimated wakefulness after sleep onset and sleep onset latency relative to the AW-64. For sedentary behavior and physical activity, the AW-64 showed a moderate agreement for activity energy expenditure, but not for sedentary, light or moderate-vigorous physical activities relative to the GT3X+. Overall our results showed good agreement of the GT3X+ with AW-64 for assessing sleep but a lack of agreement between AW-64 and GT3X+ for physical activity and sedentary behaviors. These results are likely due to the monitor placement (wrist vs hip), as well as the algorithm employed to score the data. Future validation work of existing and emerging technologies that may hold promise for 24 h continuous monitoring is needed.

The relation between sleep duration and sedentary behaviours in European adults

Too much sitting, and both short and long sleep duration are associated with obesity, but little is known on the nature of the relations between these behaviours. We therefore examined the associations between sleep duration and time spent sitting in adults across five urban regions in Europe. We used cross-sectional survey data from 6,037 adults (mean age 51.9 years (SD 16.4), 44.0% men) to assess the association between self-reported short (<6 h per night), normal (6-8 h per night) and long (>8 h per night) sleep duration with self-report total time spent sitting, time spent sitting at work, during transport, during leisure and while watching screens. The multivariable multilevel linear regression models were tested for moderation by urban region, age, gender, education and weight status. Because short sleepers have more awake time to be sedentary, we also used the percentage of awake time spent sedentary as an outcome. Short sleepers had 26.5 min day(-1) more sedentary screen time, compared with normal sleepers (CI 5.2; 47.8). No statistically significant associations were found with total or other domains of sedentary behaviour, and there was no evidence for effect modification. Long sleepers spent 3.2% higher proportion of their awake time sedentary compared with normal sleepers. Shorter sleep was associated with increased screen time in a sample of European adults, irrespective of urban region, gender, age, educational level and weight status. Experimental studies are needed to assess the prospective relation between sedentary (screen) time and sleep duration.

Isotemporal substitution of sedentary time by physical activity of different intensities and bout lengths, and its associations with metabolic risk

BACKGROUND

Time spent being sedentary, regardless of time in exercise, has been associated with metabolic risk using regression modelling. By using isotemporal substitution modelling, the effect of replacing sedentary time with an equal amount of time in physical activity (PA) of different intensities can be considered. The present study aims to investigate the effect of replacing sedentary time with time in light, moderate and vigorous PA to the prevalence of the metabolic syndrome (MetS). Also, replacement of sedentary time by PA of different bout lengths was studied.

METHODS

In total, 836 participants (52% women), aged 50-64 years, from the SCAPIS pilot study were included. Daily time spent sedentary and in PA of different intensities was assessed using hip-worn accelerometers.

RESULTS

In this cross-sectional study, replacing 10 minutes of sedentary time with the same amount of light PA was associated with significant lower MetS prevalence, odds ratio (OR) 0.96 (95% confidence interval 0.93-0.98). Replacement with moderate PA resulted in even lower OR, 0.89 (0.82-0.97), with the lowest OR for vigorous PA, 0.41 (0.26-0.66). Participants with high energy intake and high daily sedentary time benefitted more from the replacement of sedentary time with light PA. Significant associations were seen for all bout lengths of light, moderate and vigorous PA in a stepwise-like fashion from one minute to up to 120 minute bouts.

CONCLUSION

Theoretical substitutions of sedentary time with PA of any intensity and of as little as one minute were associated with significantly lower ORs for MetS. This may be an easily communicable message in clinical practice and for public health purposes.