Identifying adults' valid waking wear time by automated estimation in activPAL data collected with a 24 h wear protocol

Validation of a Modified Version of the German Sedentary Behavior Questionnaire

Background: Physical inactivity and excessive sedentary behavior (SB) are growing public health issues that require surveillance, guidelines, and targeted interventions. In addition to a variety of sophisticated technical methods, questionnaires are still an attractive method for quick, easy, comprehensive, and cost-effective estimation of SB. The aim of this study was to validate a modified version of the widely used Sedentary Behavior Questionnaire (SBQ) compared to waist-worn accelerometers as an objective measurement. Contemporary explanations covering the use of smart devices have been added to the original instrument, and sitting while handwriting was explicated in more detail. Methods: Cross-sectional data from an adult sample (n = 64, 20−85 y, 25 m, 39 f) were used in this first validation study. Based on prior investigations of the SBQ, analyses were conducted in a gender-specific manner. Criterion validity was assessed using Spearman’s Rho coefficients. The Bland−Altman method was used to test the agreement between self-reported and accelerometer-measured SB time. Results: Using the modified SBQ (mSBQ), a significant gender difference in weekly sedentary time was found. Women estimated their sedentary time to be almost 50% higher than men (median 74.5 h vs. 51.0 h). No correlation was found between the questionnaire and accelerometer data for both subgroups (rho ≤ 0.281, p ≥ 0.174). Individual differences in daily SB estimation between both methods (in relation to accelerometry) were +3.82 h ± 4.36 h for women and +0.48 h ± 2.58 h for men (p < 0.001). Conclusion: The modifications to the SBQ did not improve the correlation between self-assessment of SB and objective determination. The reasons for the presented gender-specific overestimation of the participants’ own sedentary time, which contradicts the findings of other studies, remain unclear and need to be investigated further.

Physical Activity, Sedentary Time, and Cardiometabolic Health in Heavy Goods Vehicle Drivers

OBJECTIVE

Physical inactivity, prolonged sitting, and unhealthy dietary habits are common in Heavy Goods Vehicle (HGV) drivers. These factors increase risk of long-term health conditions.

METHODS

329 HGV drivers across 25 UK depots completed a health assessment, including questionnaire completion, and objectively measured anthropometrics, blood biomarkers, physical activity (PA), and sedentary behavior.

RESULTS

The sample demonstrated a high-risk cardiometabolic health profile. 88.1% were overweight or had obesity, and 11.9% had pre-diabetes or diabetes. 28.3% had hypertension, 83.6% had clinically elevated circulating low-density lipoprotein-cholesterol concentrations (>2mmol/l), and 66.6% had high total cholesterol levels (>4mmol/l). On workdays drivers accumulated 12 hours/day of sitting, 1.7 hours/day of light PA, and 9.8 mins/day of moderate-to-vigorous PA. Associations between light PA and cardiometabolic markers were observed.

CONCLUSION

This sample presents high levels of inactivity, overweight, and obesity, and unhealthy cardiometabolic health profiles.

High Levels of Sedentary Time in Patients with COVID-19 after Hospitalisation

Many patients with COVID-19 experience severe and even fatal disease. Survivors may have long-term health consequences, but data on physical activity and sedentary behaviour are scarce. Therefore, we objectively assessed physical activity (PA) patterns among post-hospitalised patients with COVID-19 and explored associations with patient characteristics, disease severity and cardiac dysfunction. We objectively assessed PA, sedentary behaviour and sleep duration for 24 h/day during 8 days at 3-6 months after COVID-19 hospitalisation. PA and sedentary time were compared across pre-defined subgroups based on patient and disease characteristics, cardiac biomarker release during hospitalisation, abnormal transthoracic echocardiogram at 3-6 months post-hospitalisation and persistence of symptoms post-discharge. PA and sedentary behaviour were assessed in 37 patients (60 ± 10 years old; 78% male). Patients spent 4.2 [3.2; 5.3] h/day light-intensity PA and 1.0 [0.8; 1.4] h/day moderate-to-vigorous intensity PA. Time spent sitting was 9.8 [8.7; 11.2] h/day, which was accumulated in 6 [5; 7] prolonged sitting bouts (≥30 min) and 41 [32; 48] short sitting bouts (<30 min). No differences in PA and sedentary behaviour were found across subgroups, but sleep duration was higher in patients with versus without persistent symptoms (9.1 vs. 8.3 h/day, p = 0.02). Taken together, high levels of sedentary time are common at 3-6 months after COVID-19 hospitalisation, whilst PA and sedentary behaviour are not impacted by patient or disease characteristics.

Lower Amounts of Daily and Prolonged Sitting Do Not Lower Free-Living Continuously Monitored Glucose Concentrations in Overweight and Obese Adults: A Randomised Crossover Study

This study compared the short-term continuously monitored glucose responses between higher and lower amounts of prolonged sitting in overweight and obese adults under free-living conditions. In a randomised crossover design, 12 participants (age 48 ± 10 years, body mass index 33.3 ± 5.5 kg/m2) completed two four-day experimental regimens while wearing a continuous glucose monitor, as follows: (1) uninterrupted sitting (participants were instructed to sit for ≥10 h/day and accrue ≥7, 1 h sitting bouts each day), and (2) interrupted sitting (participants were instructed to interrupt sitting every 30 min during ten of their waking hours with 6−10 min of activity accrued in each hour). Linear mixed models compared outcomes between regimens. None of the continuously monitored glucose variables differed between regimens, e.g., 24 h net incremental area under the glucose curve was 5.9 [95% CI: −1.4, 13.1] and 5.6 [95% CI: −1.7, 12.8] mmol/L∙24 h, respectively (p = 0.47). Daily sitting (−58 min/day, p = 0.001) and sitting bouts lasting ≥30 min (−99 min/day, p < 0.001) were significantly lower and stepping time significantly higher (+40 min/day, p < 0.001) in the interrupted sitting than the uninterrupted sitting regimen. In conclusion, lower amounts of daily and prolonged sitting did not improve free-living continuously measured glucose among overweight and obese adults.

How reliable is measurement of posture during sleep: real-world measurement of body posture and movement during sleep using accelerometers

Objective Understanding sleeping behaviours could improve prevention and treatment of sleep problems and associated health conditions. This study aimed to evaluate a method to assess body posture and movement during sleep using trunk-worn accelerometers for 28 days. Approach Participants (50 adults with low back pain (66% female); aged 32(±9) years) wore two activPAL-micro sensors (thigh, trunk) during their normal daily life for 28 consecutive days. Parameters related to body posture (e.g., time spent lying supine or prone) and movement (e.g., number of turns) during sleep were calculated for each night. Average values for each parameter were identified for different periods, the Spearman-Brown Prophecy Formula was used to estimate the minimum number of nights required to obtain a reliable estimate of each parameter, and repeatability of measures between different weeks was calculated. Main Results Participants spent 8.1(±0.8) hours asleep and most time (44%) was spent in a supine posture. The minimum number of nights required for reliable estimates varied between sleep parameters, range 4-21 nights. The most stable parameters (i.e., requiring less than seven nights) were "average activity", "no. of turns", "time spent prone", and "posture changes in the first hour". Some measures differed substantially between weeks. Significance Most sleep parameters related to body posture and movement require a week or more of monitoring to provide reliable estimates of behaviour over one month. Notably, one week may not reflect behaviour in another week, and the time varying nature of sleep needs to be considered.

Contrasting compositions of sitting, standing, stepping, and sleeping time: associations with glycaemic outcome by diabetes risk

BACKGROUND

Recent evidence suggests that prolonged sitting and its adverse impact on glycaemic indicators appear to be proportional to the degree of insulin resistance. To investigate this finding in a free-living context, we aimed to examine associations of device-measured 24-h time-use compositions of sitting, standing, stepping, and sleeping with fasting glucose (FPG) and 2 h post-load glucose (2hPLG) levels, and to examine separately the associations with time-use compositions among those at lower and at higher risk of developing type 2 diabetes.

METHODS

Cross-sectional analyses examined thigh-worn inclinometer data (activPAL, 7 day, 24 h/day protocol) from 648 participants (aged 36-80 years) at either lower (< 39 mmol/mol; < 5.7% HbA1c) or higher (≥39 mmol/mol; ≥5.7% HbA1c) diabetes risk from the 2011-2012 Australian Diabetes, Obesity and Lifestyle study. Multiple linear regression models were used to examine associations of differing compositions with FPG and 2hPLG, with time spent in each behaviour allowed to vary up to 60 min.

RESULTS

In general, the associations with the FPG within the time-use compositions were small, with statistically significant associations observed for sitting and sleeping (in the lower diabetes risk group) and standing (in higher diabetes risk group) only. For 2hPLG, statistically significant associations were observed for stepping only, with findings similar between lower (β = - 0.12 95%CI:-0.22, - 0.02) and higher (β = - 0.13 95%CI:-0.26, - 0.01) risk groups. Varying the composition had minimal impact on FPG; however 1 h less sitting time and equivalent increase in standing time was associated with attenuated FPG levels in higher risk only (Δ FPG% = - 1.5 95%CI: - 2.4, - 0.5). Large differences in 2hPLG were observed for both groups when varying the composition. One hour less sitting with equivalent increase in stepping was associated with attenuated 2hPLG, with estimations similar in lower (Δ 2hPLG% = - 3.8 95%CI: - 7.3, - 0.2) and higher (Δ 2hPLG% = - 5.0 95%CI: - 9.7, - 0.0) risk for diabetes.

CONCLUSIONS

In middle-aged and older adults, glycaemic control could be improved by reducing daily sitting time and replacing it with stepping. Standing could also be beneficial for those at higher risk of developing type 2 diabetes.

Evaluation of a natural workspace intervention with active design features on movement, interaction and health

BACKGROUND

There is increasing focus on designing workspaces that promote less sitting, more movement and interaction to improve physical and mental health.

OBJECTIVE

This study evaluates a natural intervention of a new workplace with active design features and its relocation to a greener and open space.

METHODS

An ecological model was used to understand how organisations implement change. Pre and post survey data from 221 matched cases of workers and accelerometery data (n = 50) were analysed.

RESULTS

Results show a decrease in occupational sitting (-20.65 mins/workday, p = 0.001) and an increase in workplace walking (+5.61 mins/workday, p = 0.001) using survey data, and accelerometery data (occupational sitting time: -31.0 mins/workday, p = 0.035, standing time: +22.0 mins/workday, p = 0.022, stepping time: +11.0 mins/workday, p = 0.001). Improvements in interaction, musculoskeletal pain and mental health were reported.

CONCLUSIONS

Application of the ecological model shows that the organisation understands how to target the built environment and social/cultural environment but not how to target behaviour change at the individual level.

Patterns and correlates of sedentary behaviour among people with multiple sclerosis: a cross-sectional study

High levels of sedentary behaviour are associated with poor health outcomes in people with multiple sclerosis (MS). Identifying modifiable correlates of sedentary behaviour for people with MS is essential to design effective intervention strategies to minimise sedentary time. This study aimed to quantify patterns and identify correlates of sedentary behaviour among adults with MS. Fatigue, self-efficacy, walking capability, the physical and psychological impact of MS, health-related quality of life, and participation and autonomy were assessed by questionnaire. Participants wore an activPAL monitor. Total (min/day), prolonged bouts (≥ 30 min) and breaks in sedentary time were calculated. Associations were examined using regression analysis adjusted for demographic and clinical confounders. Fifty-six adults with MS participated (mean ± SD age: 57.0 ± 9.25 years; 66% female). Self-efficacy for control over MS was associated with sedentary time (β = 0.16, 95% CI 0.01, 0.30). Self-efficacy in function maintenance (β = 0.02, 95% CI 0.00, 0.04), health-related quality of life (EuroQol-5D) (β = 31.60, 95% CI 7.25, 55.96), and the autonomy indoors subscale of the Impact on Participation and Autonomy Questionnaire (β = − 5.11, 95% CI − 9.74, − 0.485) were associated with breaks in sedentary time. Future studies should consider self-efficacy, health-related quality of life and participation and autonomy as potential components of interventions to reduce sedentary behaviour.

Are individual and social factors specific to the home associated with children's behaviour and physical environment at home

This study used linear regression analyses to investigate the influence of parent-reported home-specific social and individual factors on: (i) 235 children's home-based objectively measured overall sitting time, breaks in sitting, and PA, and; (ii) the home physical environment via an audit. Parental importance assigned to active play for children was positively associated with PA equipment (accessibility and availability), as well as light physical activity (LPA) and sitting breaks on both weekdays and weekend days. Parental preference for being active at home and limits on screen-time were associated with less household media equipment and portable media equipment, respectively. Greater parental importance placed on playing electronic games/using computers for fun was associated with less LPA and more sitting on weekdays. Further, children who preferred being sedentary sat more and engaged in less moderate-vigorous physical activity (MVPA) on weekdays. Parental and child preferences and priorities, as well as parental rules for activity at home, were associated with children's home-based sitting and PA, especially on weekdays. Such factors were also associated with the physical environment in the expected directions. The findings suggest interventions need to target social and individual factors, alongside adapting the physical environment to create homes more promotive of physical activity.

Effect of a personalised mHealth home-based training application on physical activity levels during and after centre-based cardiac rehabilitation: rationale and design of the Cardiac RehApp randomised control trial

Many patients lapse into a physically inactive lifestyle within months after cardiac rehabilitation (CR) programme completion. A mobile-health (mHealth) home-based training application can be used to intensify and/or prolong the CR programme to induce long-lasting improvements of habitual physical activity levels. This study will assess the effect of an additional home-based training module during CR and post-CR on habitual physical activity levels among coronary artery disease patients. A total of 132 patients (>18 years old) will be recruited in an 18-week randomised controlled trial with four arms: (1) 6 weeks centre-based CR (ie, standard care), (2) 6 weeks combined centre-based+mHealth home-based CR, (3) 6 weeks centre-based CR followed by 12 weeks mHealth home-based CR, (4) 6 weeks combined centre-based+mHealth home-based CR followed by 12 weeks mHealth home-based CR. The intervention groups will receive a daily and personalised exercise training using a smartphone application (Virtual Training) in addition to and/or as extension of the centre-based CR programme. The participants will be assessed prior to the centre-based CR programme, after completion of the 6-week CR programme and after the 12 weeks extension. Primary outcome will be objectively measured habitual physical activity levels expressed as moderate to vigorous intensity activities (min/week). Secondary outcome parameters include sedentary behaviour, physical fitness (estimated VO₂max), handgrip strength, cardiovascular risk profile, quality of life and cardiac anxiety scores. The findings of the Cardiac RehApp study will provide insight into the added value of a personalised mHealth home-based training application on physical activity levels during and after centre-based CR. Trial registration number: NL72182.091.019.

Validity of Two Awake Wear-Time Classification Algorithms for activPAL in Youth, Adults, and Older Adults

Background

The authors assessed agreement between participant diaries and two automated algorithms applied to activPAL (PAL Technologies Ltd, Glasgow, United Kingdom) data for classifying awake wear time in three age groups.

Methods

Study 1 involved 20 youth and 23 adults who, by protocol, removed the activPAL occasionally to create nonwear periods. Study 2 involved 744 older adults who wore the activPAL continuously. Both studies involved multiple assessment days. In-bed, out-of-bed, and nonwear times were recorded in the participant diaries. The CREA (in PAL processing suite) and ProcessingPAL (secondary application) algorithms estimated out-of-bed wear time. Second- and day-level agreement between the algorithms and diary was investigated, as were associations of sedentary variables with self-rated health.

Results

The overall accuracy for classifying out-of-bed wear time as compared with the diary was 89.7% (Study 1) to 95% (Study 2) for CREA and 89.4% (Study 1) to 93% (Study 2) for ProcessingPAL. Over 90% of the nonwear time occurring in nonwear periods >165 min was detected by both algorithms, while <11% occurring in periods ≤165 min was detected. For the daily variables, the mean absolute errors for each algorithm were generally within 0-15% of the diary mean. Most Spearman correlations were very large (≥.81). The mean absolute errors and correlations were less favorable for days on which any nonwear time had occurred. The associations between sedentary variables and self-rated health were similar across processing methods.

Conclusion

The automated awake wear-time classification algorithms performed similarly to the diary information on days without short (≤2.5-2.75 hr) nonwear periods. Because both diary and algorithm data can have inaccuracies, best practices likely involve integrating diary and algorithm output.

Preliminary efficacy of the "SitLess with MS" intervention for changing sedentary behaviour, symptoms, and physical performance in multiple sclerosis

PURPOSE

People with multiple sclerosis (MS) sit (i.e., are sedentary) more than peers. We examined the preliminary efficacy of an internet-based intervention that focuses on sitting less and moving more for changing sedentary behaviour outcomes, symptoms, QOL, and physical performance in adults with MS.

METHODS

Persons with mild-to-moderate disability from MS took part in a 15-week pre-post trial. Outcomes including sedentary behaviour, representative symptoms (e.g., fatigue, pain), QOL and physical performance measures (e.g., walking speed) were measured at three time points: pre-post intervention and at follow-up. An unstructured linear mixed-effects model was used to determine change over time per outcome.

RESULTS

Forty-one persons with MS participated (age 50 ± 10.3 years). There were significant reductions in total sedentary time (d = 0.34) and the number of long (≥30 min) bouts of sedentary time (d = 0.39) post-intervention. All symptoms and physical performance measures were significantly improved following the intervention, with effects sizes greatest for fatigue (d = 0.61) and depression (d = 0.79). Changes were maintained during the 7-week follow-up, except for all sedentary behaviour outcomes and sleep quality. Cognition did not change.

CONCLUSIONS

This study provides preliminary support for the efficacy of an intervention focused on sitting less and moving more for improving symptoms in adults with MS.IMPLICATIONS FOR REHABILITATIONThis research provides preliminary evidence that an intervention aimed at reducing sedentary behaviour and increasing light intensity activity throughout the day can have an impact.Fatigue, depression and anxiety, symptoms frequently encountered by people with MS, showed the greatest improvement following the intervention.Weekly coaching sessions including discussions about results from activity monitoring provided motivation for participants.

TRIAL REGISTRATION

The "SitLess with MS" feasibility study was registered at ClinicalTrials.gov Trial Registration Number: NCT03136744. Date of registration was 2 May 2017. Find at https://clinicaltrials.gov/ct2/show/NCT03136744.

Sleep duration and sleep efficiency in UK long-distance heavy goods vehicle drivers

OBJECTIVES

To profile sleep duration and sleep efficiency in UK long-distance heavy goods vehicle (HGV) drivers and explore demographic, occupational and lifestyle predictors of sleep.

METHODS

Cross-sectional analyses were carried out on 329 HGV drivers (98.5% men) recruited across an international logistics company within the midland's region, UK. Sleep duration and efficiency were assessed via wrist-worn accelerometry (GENEActiv) over 8 days. Proportions of drivers with short sleep duration (<6 hour/24 hours and <7 hour/24 hours) and inadequate sleep efficiency (<85%) were calculated. Demographic, occupational and lifestyle data were collected via questionnaires and device-based measures. Logistic regression assessed predictors of short sleep duration and inadequate sleep efficiency.

RESULTS

58% of drivers had a mean sleep duration of <6 hour/24 hours, 91% demonstrated <7-hour sleep/24 hours and 72% achieved <85% sleep efficiency. Sleeping <6 hour/24 hours was less likely in morning (OR 0.45, 95% CI 0.21 to 0.94) and afternoon (OR 0.24, CI 0.10 to 0.60) shift workers (vs night) and if never smoked (vs current smokers) (OR 0.45, CI -0.22 to 0.92). The likelihood of sleeping <7 hour/24 hours reduced with age (OR 0.92, CI 0.87 to 0.98). The likelihood of presenting inadequate sleep efficiency reduced with age (OR 0.96, CI 0.93 to 0.99) and overweight body mass index category (vs obese) (OR 0.47, CI 0.27 to 0.82).

CONCLUSIONS

The high prevalence of short sleep duration and insufficient sleep quality (efficiency) rate suggest that many HGV drivers have increased risk of excessive daytime sleepiness, road traffic accidents and chronic disease. Future sleep research in UK HGV cohorts is warranted given the road safety and public health implications.

Sit Less and Move More-A Multicomponent Intervention With and Without Height-Adjustable Workstations in Contact Center Call Agents: A Pilot Randomized Controlled Trial

OBJECTIVE

To pilot a multicomponent intervention to sit less and move more, with (SLAMM+) and without (SLAMM) height-adjustable workstations, in contact center call agents.

METHODS

Agents were individually randomized to SLAMM or SLAMM+ in this 10-month, parallel, open-label, pilot trial. Mixed-methods assessed response, recruitment, retention, attrition and completion rates, adverse effects, trial feasibility and acceptability, preliminary effectiveness on worktime sitting, and described secondary outcomes.

RESULTS

The participant recruitment rate, and randomization, data collection, and interventions were mostly acceptable. Refinements to organization recruitment were identified. High staff turnover negatively impacted retention and completion rates. The multicomponent intervention with height-adjustable workstations has potential to reduce sitting time at work.

CONCLUSIONS

The demonstrated findings will help prepare for a future randomized controlled trial designed to assess the effect of the interventions.

Objectively-Measured Activity Patterns are Associated with Home Blood Pressure in Memory Clinic Patients

Background:

Physicians are cautious to prescribe antihypertensive drugs in frail older adults because of the potential adverse effects, especially in those with cognitive complaints. Lifestyle aspects might provide safe targets to lower blood pressure in older adults.

Objective:

Our goal was to evaluate the associations between activity patterns and blood pressure in memory clinic patients.

Methods:

We used an observational cross-sectional study to measure activity patterns with the ActivPAL accelerometer, and simultaneous home blood pressure levels in memory clinic patients (age range 51–87 years old). Office blood pressure was assessed during routine clinical practice.

Results:

41 patients (mean age of 74.3 (7.7) years of age, 46% female) were included. Sedentary parameters were associated with higher mean home blood pressure, with the strongest correlation between more prolonged sitting bouts and higher SBP (r = 0.58, p < .0001). Physical activity parameters were negatively associated with mean home blood pressure. Adjusted regression estimates remained significant, showing, e.g., a 4.5 (95% CI = 1.6;7.4) mmHg increase in SBP for every hour of sitting per day and a –1.0 (95% CI = –1.8;–0.2) mmHg decrease in DBP for every additional 1000 steps per day. No strong correlations were found between any of the activity pattern variables and office blood pressure.

Conclusion:

Associations between activity pattern variables and blood pressure were only found with home blood pressure measurements, not with office measurements. Longitudinal evaluations of these associations are now needed to explore if reducing prolonged sedentary bouts and increasing step count indeed serve as safe targets to lower blood pressure.

Socioeconomic correlates of sedentary time during pregnancy among women at risk of gestational diabetes in the UK

Little is known about the relationship between socioeconomic position (SEP) and duration and patterning of objectively measured sedentary time (ST) among adults, especially adults at high risk of diabetes. The aim of this study was to examine cross-sectional associations of SEP with ST (total, prolonged ST, breaks in ST) and self-reported TV time among pregnant women at risk of gestational diabetes in the UK. At 20 weeks' gestation, pregnant women (n=174) wore an activPAL accelerometer and reported their usual TV time. Generalized linear mixed models were used to test associations of education, household income and area-level deprivation (separately and with mutual adjustment) with total ST, prolonged ST and breaks in ST. Logistic regression models were used to test associations between SEP indicators and high (≥2h/day) TV time. Those with the lowest education, lowest household income and highest area-level deprivation had the lowest ST and lowest prolonged ST. After mutual adjustment, area-level deprivation remained associated with total ST (β=0.10 [0.01, 0.20]). There was an inverse association between area-level deprivation and breaks in sedentary time (exp(b)=1.11 [1.01, 1.22]). Education was the only SEP correlate of high TV time, with more of those with least education reporting high TV time; this association persisted after adjustment for household income and area-level deprivation. The association between SEP and total and prolonged ST (positive) was the opposite of the association between education and high TV time (negative) in this sample of high-risk pregnant women. These findings should inform interventions to reduce sedentary time.

Descriptive Epidemiology of Interruptions to Free-Living Sitting Time in Middle-Age and Older Adults

National guidelines recommend physically active interruptions to sitting time, however, the characteristics of these interruptions are broadly stated and ill-defined. A robust methodology for population surveillance for such interruptions is needed.

PURPOSE

To describe the frequency and characteristics (i.e., duration, stepping time, and estimated intensity) of all interruptions and physically active interruptions to adults' free-living sitting time (i.e., transitions from sitting to upright posture) across segments of the population.

METHODS

Australian Diabetes, Obesity and Lifestyle (AusDiab) study participants (321 men; 406 women; mean ± SD 58.0 ± 10.3 years) wore the activPAL3TM for ≥1 valid day. The characteristics of interruptions from laboratory studies demonstrating health benefits were selected to define active interruptions (≥5 min upright and/or ≥ 2 min stepping) and ambulatory interruptions (≥2 min stepping). The frequency and characteristics of all, active, and ambulatory interruptions were described and compared by age, gender, diabetes status, and body mass index.

RESULTS

Adults averaged 55.0 ± 21.8 interruptions per day, but only 20.3 ± 6.7 were active and 14.0 ± 5.4 were ambulatory. Median (25th, 75th percentile) duration was 2.6 (0.9, 7.8) minutes, stepping time was 0.8 (0.3, 2.0) minutes, and estimated energy expenditure was 4.3 (1.4, 12.5) MET-min. Those who were older, had obesity, or had diabetes had significantly (p < 0.05) fewer interruptions of all types and less stepping time during active interruptions than their counterparts (Cohen's d < 0.2).

CONCLUSION

Free-living interruptions were often less active than interruptions performed in effective acute laboratory studies and their content varied widely between population groups. Monitoring all interruptions as well as those that are more active is advisable to provide a comprehensive understanding of free-living sedentary behavior.

The "Worktivity" mHealth intervention to reduce sedentary behaviour in the workplace: a feasibility cluster randomised controlled pilot study

Background

Office work generally consists of high amounts of sedentary behaviour (SB) which has been associated with negative health consequences. We developed the “WorktivIty” mobile app to help office workers reduce their SB through self-monitoring and feedback on sedentary time, prompts to break sedentary time, and educational facts. The aim of this paper is to report the feasibility of delivering the Worktivity intervention to desk-based office workers in the workplace setting and describe methodological considerations for a future trial.

Methods

We conducted a three-arm feasibility cluster randomised controlled pilot study over an 8-week period with full time-desk based employees. Clustered randomisation was to one of three groups: Worktivity mobile app (MA; n = 20), Worktivity mobile app plus SSWD (MA+SSWD; n = 20), or Control (C; n = 16). Feasibility was assessed using measures of recruitment and retention, intervention engagement, intervention delivery, completion rates and usable data, adverse events, and acceptability.

Results

Recruitment of companies to participate in this study was challenging (8% of those contacted), but retention of individual participants within the recruited groups was high (81% C, 90% MA + SSWD, 95% MA). Office workers’ engagement with the app was moderate (on average 59%). Intervention delivery was partially compromised due to diminishing user engagement and technical issues related to educational fact delivery. Sufficient amounts of useable data were collected, however either missing or unusable data were observed with activPAL™, with data loss increasing at each follow up time point. No serious adverse events were identified during the study. The majority of participants agreed that the intervention could be implemented within the workplace setting (65% MA; 72% MA + SSWD) but overall satisfaction with the intervention was modest (58% MA; 39% MA + SSWD).

Conclusions

The findings suggest that, in principle, it is feasible to implement a mobile app-based intervention in the workplace setting however the Worktivity intervention requires further technical refinements before moving to effectiveness trials. Challenges relating to the initial recruitment of workplaces and maintaining user engagement with the mHealth intervention over time need to be addressed prior to future large-scale implementation. Further research is needed to identify how best to overcome these challenges.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11473-6.

An Exploration of Sedentary Behavior Patterns in Community-Dwelling People With Stroke: A Cluster-Based Analysis

BACKGROUND AND PURPOSE

Long periods of daily sedentary time, particularly accumulated in long uninterrupted bouts, are a risk factor for cardiovascular disease. People with stroke are at high risk of recurrent events and prolonged sedentary time may increase this risk. We aimed to explore how people with stroke distribute their periods of sedentary behavior, which factors influence this distribution, and whether sedentary behavior clusters can be distinguished?

METHODS

This was a secondary analysis of original accelerometry data from adults with stroke living in the community. We conducted data-driven clustering analyses to identify unique accumulation patterns of sedentary time across participants, followed by multinomial logistical regression to determine the association between the clusters, and the total amount of sedentary time, age, gender, body mass index (BMI), walking speed, and wake time.

RESULTS

Participants in the highest quartile of total sedentary time accumulated a significantly higher proportion of their sedentary time in prolonged bouts (P < 0.001). Six unique accumulation patterns were identified, all of which were characterized by high sedentary time. Total sedentary time, age, gender, BMI, and walking speed were significantly associated with the probability of a person being in a specific accumulation pattern cluster, P < 0.001 - P = 0.002.

DISCUSSION AND CONCLUSIONS

Although unique accumulation patterns were identified, there is not just one accumulation pattern for high sedentary time. This suggests that interventions to reduce sedentary time must be individually tailored.Video Abstract available for more insight from the authors (see the Video Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A343).

The PERSonalized Glucose Optimization Through Nutritional Intervention (PERSON) Study: Rationale, Design and Preliminary Screening Results

Background: It is well-established that the etiology of type 2 diabetes differs between individuals. Insulin resistance (IR) may develop in different tissues, but the severity of IR may differ in key metabolic organs such as the liver and skeletal muscle. Recent evidence suggests that these distinct tissue-specific IR phenotypes may also respond differentially to dietary macronutrient composition with respect to improvements in glucose metabolism.

Objective: The main objective of the PERSON study is to investigate the effects of an optimal vs. suboptimal dietary macronutrient intervention according to tissue-specific IR phenotype on glucose metabolism and other health outcomes.

Methods: In total, 240 overweight/obese (BMI 25 – 40 kg/m²) men and women (age 40 – 75 years) with either skeletal muscle insulin resistance (MIR) or liver insulin resistance (LIR) will participate in a two-center, randomized, double-blind, parallel, 12-week dietary intervention study. At screening, participants undergo a 7-point oral glucose tolerance test (OGTT) to determine the hepatic insulin resistance index (HIRI) and muscle insulin sensitivity index (MISI), classifying each participant as either “No MIR/LIR,” “MIR,” “LIR,” or “combined MIR/LIR.” Individuals with MIR or LIR are randomized to follow one of two isocaloric diets varying in macronutrient content and quality, that is hypothesized to be either an optimal or suboptimal diet, depending on their tissue-specific IR phenotype (MIR/LIR). Extensive measurements in a controlled laboratory setting as well as phenotyping in daily life are performed before and after the intervention. The primary study outcome is the difference in change in disposition index, which is the product of insulin sensitivity and first-phase insulin secretion, between participants who received their hypothesized optimal or suboptimal diet.

Discussion: The PERSON study is one of the first randomized clinical trials in the field of precision nutrition to test effects of a more personalized dietary intervention based on IR phenotype. The results of the PERSON study will contribute knowledge on the effectiveness of targeted nutritional strategies to the emerging field of precision nutrition, and improve our understanding of the complex pathophysiology of whole body and tissue-specific IR.

Clinical Trial Registration:https://clinicaltrials.gov/ct2/show/NCT03708419, clinicaltrials.gov as NCT03708419.

The Effects of Interrupting Prolonged Sitting With Frequent Bouts of Light-Intensity Standing Exercises on Blood Pressure in Stroke Survivors: A Dose Escalation Trial

BACKGROUND

Interrupting prolonged sitting acutely lowers blood pressure in nonstroke populations. However, the dose-response effect in stroke survivors is unknown. The authors investigated different doses of light-intensity standing exercises that interrupt prolonged sitting and reduce blood pressure immediately and over 24 hours in stroke survivors.

METHODS

Within-participant, laboratory-based, dose escalation trial. Conditions (8 h) were prolonged sitting and 2 experimental conditions of standing exercises with increasing frequency (3 cohorts, 2 × 5 min to 6 × 5 min). The primary outcome is the mean systolic blood pressure.

RESULTS

Twenty-nine stroke survivors (aged 66 [12] y) participated. Frequent bouts of standing exercises lowered the mean systolic blood pressure following the 4 × 5-minute (-2.1 mm Hg; 95% confidence interval [CI], -3.6 to -0.6) and 6 × 5-minute conditions (-2.3 mm Hg; 95% CI, -4.2 to -0.5) compared with prolonged sitting. Diastolic blood pressure was lowered following the 6 × 5-minute condition (-1.4 mm Hg; 95% CI, -2.7 to -0.2). The 24-hour systolic blood pressure increased following the 2 × 5-minute condition (6.9 mm Hg; 95% CI, 3.1 to 10.6).

CONCLUSIONS

Interrupting prolonged sitting with more frequent bouts of standing exercises lowers systolic and diastolic blood pressure in stroke survivors. However, reductions may only be short term, and investigations on sustained effects are warranted.

Do levels of sedentary behaviour and physical activity differ according to weight-bearing status after lower limb fracture? A prospective cohort study

Background/purpose:

To determine whether sedentary behaviour and physical activity differ according to initial weight-bearing status 2 weeks and 6 months after lower limb (LL) fracture.

Methods:

Two weeks and 6 months following LL fracture, 47 adults aged 18–69 wore ActiGraph and activPAL accelerometers for 10 days. Sitting time, steps, and moderate-intensity physical activity (MPA) were compared between weight-bearing (WB) and non-weight-bearing (NWB) groups.

Results:

Two weeks post-discharge, the NWB group sat significantly more than the WB group (median: 14.1 h/day vs. 13.3 h/day; p = 0.04). These differences were apparent for female and middle-aged participants. At 6 months, there were no significant differences between weight-bearing groups for sitting time, steps or MPA.

Conclusion:

Weight-bearing restriction had an early impact on sitting time, but this impact lessened over time. While considering the need for rest, advice about reducing sitting time may be particularly important for people who are NWB post-fracture.

Modelling the Reallocation of Time Spent Sitting into Physical Activity: Isotemporal Substitution vs. Compositional Isotemporal Substitution

Isotemporal substitution modelling (ISM) and compositional isotemporal modelling (CISM) are statistical approaches used in epidemiology to model the associations of replacing time in one physical behaviour with time in another. This study’s aim was to use both ISM and CISM to examine and compare associations of reallocating 60 min of sitting into standing or stepping with markers of cardiometabolic health. Cross-sectional data collected during three randomised control trials (RCTs) were utilised. All participants (n = 1554) were identified as being at high risk of developing type 2 diabetes. Reallocating 60 min from sitting to standing and to stepping was associated with a lower BMI, waist circumference, and triglycerides and higher high-density lipoprotein cholesterol using both ISM and CISM (p < 0.05). The direction and magnitude of significant associations were consistent across methods. No associations were observed for hemoglobin A1c, total cholesterol, or low-density lipoprotein cholesterol for either method. Results of both ISM and CISM were broadly similar, allowing for the interpretation of previous research, and should enable future research in order to make informed methodological, data-driven decisions.

Sedentary time and physical activity patterns of stroke survivors during the inpatient rehabilitation week

Physical activity is recommended after stroke. However, the rehabilitation day is largely spent sedentary. Understanding patterns of physical activity across the rehabilitation week may help identify opportunities to improve participation. We aimed to examine: (1) differences between weekday and weekend sedentary time and physical activity, (2) the pattern of 24-h rehabilitation activity. Participants with stroke (n = 29) wore an activity monitor continuously during the final 7-days of inpatient rehabilitation. Linear mixed models (adjusted for waking hours) were performed with activity (sedentary, steps per day, walking time) as the dependent variable, and day type (weekday or weekend) as the independent variable. Patterns of upright time during the 24-h period were determined by averaging daily activity in 60-min intervals and generating a heat map of activity levels as a function of time. Participant mean age was 69 (SD 13) years (52% male) and mean National Institutes of Health Stroke Scale score was 7.0 (SD, 5.5). There was no significant difference in sedentary time between weekdays and weekends. At the weekend, participants spent 8.4 min less time walking (95% CI, -12.1 to -4.6) taking 624 fewer steps/day (95% CI, -951 to -296) than during the week. Activity patterns showed greatest upright time in the morning during the week. Afternoon and evening activities were low on all days. Sedentary time did not change across the 7-day rehabilitation week, but less walking activity occurred on the weekend. There are opportunities for stroke survivors to increase physical activity during afternoons and evenings and on weekend mornings during rehabilitation.

How Accurate and Precise Can We Measure the Posture and the Energy Expenditure Component of Sedentary Behaviour with One Sensor?

Sedentary behaviour is an emergent public health topic, but there is still no method to simultaneously measure both components of sedentary behaviour-posture and energy expenditure-with one sensor. This study investigated the accuracy and precision of measuring sedentary time when combining the proprietary processing of a posture sensor (activPAL) with a new energy expenditure algorithm and the proprietary processing of a movement sensor (ActiGraph) with a published posture algorithm. One hundred office workers wore both sensors for an average of 7 days. The activPAL algorithm development used 38 and the subsequent independent method comparison 62 participants. The single sensor sedentary estimates were compared with Bland-Atman statistics to the Posture and Physical Activity Index, a combined measurement with both sensors. All single-sensor methods overestimated sedentary time. However, adding the algorithms reduced the overestimation from 129 to 21 (activPAL) and from 84 to 7 min a day (ActiGraph), with far narrower 95% limits of agreements. Thus, combining the proprietary data with the algorithms is an easy way to increase the accuracy and precision of the single sensor sedentary estimates and leads to sedentary estimates that are more precise at the individual level than those of the proprietary processing are at the group level.

Device-assessed total and prolonged sitting time: associations with anxiety, depression, and health-related quality of life in adults

OBJECTIVE

Assessment of sitting has been challenging and nuances in the length of sitting are often missed.

METHODS

The present study assessed total, short and prolonged sitting time, and number of breaks from sitting, and their association with anxiety, depression, and health-related quality of life (HRQoL). Adults (M=59.1 years) in three studies (n=1,574) wore the activPAL accelerometer (thigh) to obtain a measure of sitting, and the Actigraph accelerometer (hip) for estimating moderate-to-vigorous physical activity (MVPA). Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale, and HRQoL using the EQ-5D-5L (for health state and utility scores). Generalised linear modelling tested associations.

RESULTS

Total and prolonged sitting were associated with higher depression [total: β = 0.132 (0.010, 0.254); prolonged: β = 0.178 (0.053, 0.304)] and worse HRQoL health state scores [(total: β = -0.985 (-1.471, -0.499); prolonged: β = -0.834 (-1.301, -0.367)] and utility scores [(total: β = -0.008 (-0.012, -0.003); prolonged: β = -0.008 (-0.012, -0.004)], after controlling for covariates. MVPA was associated with better HRQoL health state and utility scores [health state: β =0.554 (0.187, 0.922); utility: β = 0.001 (0.001, 0.002)]. Total and prolonged sitting were associated with a 14% increased odds of being in the borderline/abnormal category for depression. No interactions were observed between MVPA status (active vs. inactive) and total or prolonged sitting. Anxiety was unrelated to any sitting variable.

CONCLUSION

Device-based measures of both total and prolonged sitting time were associated with depression and health-related quality of life, but not anxiety.

The Influence of Sitting, Standing, and Stepping Bouts on Cardiometabolic Health Markers in Older Adults

Aside from total time spent in physical activity behaviors, how time is accumulated is important for health. This study examined associations between sitting, standing, and stepping bouts, with cardiometabolic health markers in older adults. Participants from the Mitchelstown Cohort Rescreen Study (N = 221) provided cross-sectional data on activity behaviors (assessed via an activPAL3 Micro) and cardiometabolic health. Bouts of ≥10-, ≥30-, and ≥60-min sitting, standing, and stepping were calculated. Linear regression models were fitted to examine the associations between bouts and cardiometabolic health markers. Sitting (≥10, ≥30, and ≥60 min) and standing (≥10 and ≥30 min) bouts were detrimentally associated with body composition measures, lipid markers, and fasting glucose. The effect for time spent in ≥60-min sitting and ≥30-min standing bouts was larger than shorter bouts. Fragmenting sitting with bouts of stepping may be targeted to benefit cardiometabolic health. Further insights for the role of standing need to be elicited.

Acute Effects of Frequent Light-Intensity Standing-Based Exercises That Interrupt 8 Hours of Prolonged Sitting on Postprandial Glucose in Stroke Survivors: A Dose-Escalation Trial

BACKGROUND

Interrupting prolonged sitting can attenuate postprandial glucose responses in overweight adults. The dose-response effect in stroke survivors is unknown. The authors investigated the effects of interrupting 8 hours of prolonged sitting with increasingly frequent bouts of light-intensity standing-based exercises on the postprandial glucose response in stroke survivors.

METHODS

Within-participant, laboratory-based, dose-escalation trial. Participants completed three 8-hour conditions: prolonged sitting and 2 experimental conditions. Experimental conditions involved light-intensity standing-based exercises of increasing frequency (2 × 5 min to 6 × 5 min bouts). Postprandial glucose is reported.

RESULTS

Twenty-nine stroke survivors (aged 66 y) participated. Interrupting 8 hours of prolonged sitting with light-intensity standing-based exercises every 90 minutes significantly decreased postprandial glucose (positive incremental area under the curve; -1.1 mmol/L·7 h; 95% confidence interval, -2.0 to -0.1). In the morning (08:00-11:00), postprandial glucose decreased during the 4 × 5 minutes and 6 × 5 minutes conditions (positive incremental area under the curve; -0.8 mmol/L·3 h; 95% confidence interval, -1.3 to -0.3 and -0.8 mmol/L·3 h; 95% confidence interval, -1.5 to -0.2, respectively) compared with prolonged sitting.

CONCLUSION

Interrupting 8 hours of prolonged sitting at least every 90 minutes with light-intensity standing-based exercises attenuates postprandial glucose in stroke survivors. During the morning, postprandial glucose is attenuated when sitting is interrupted every 60 and 90 minutes.

Stand Out in Class: Investigating the Potential Impact of a Sit-Stand Desk Intervention on Children's Sitting and Physical Activity during Class Time and after School

Sedentary behaviour (sitting) is a risk factor for adverse health outcomes. The classroom environment has traditionally been associated with prolonged periods of sitting in children. The aim of this study was to examine the potential impact of an environmental intervention, the addition of sit–stand desks in the classroom, on school children’s sitting and physical activity during class time and after school. The ‘Stand Out in Class’ pilot trial was a two-arm cluster randomised controlled trial conducted in eight primary schools with children from a mixed socioeconomic background. The 4.5 month environmental intervention modified the physical (six sit–stand desks replaced standard desks) and social (e.g., teachers’ support) environment. All children wore activPAL and ActiGraph accelerometers for 7 days at baseline and follow-up. In total 176 children (mean age = 9.3 years) took part in the trial. At baseline, control and intervention groups spent more than 65% of class time sitting, this changed to 71.7% and 59.1% at follow-up, respectively (group effect p < 0.001). The proportion of class time spent standing and stepping, along with the proportion of time in light activity increased in the intervention group and decreased in the control group. There was no evidence of any compensatory effects from the intervention after school. Incorporating sit–stand desks to change the classroom environment at primary school appears to be an acceptable strategy for reducing children’s sedentary behaviour and increasing light activity especially during class time. Trial registration: ISRCTN12915848 (registered: 09/11/16).

Secondary Prevention of Stroke: Study Protocol for a Telehealth-Delivered Physical Activity and Diet Pilot Randomized Trial (ENAbLE-Pilot)

BACKGROUND

Increasing physical activity (PA) and improving diet quality are opportunities to improve secondary stroke prevention, but access to appropriate services is limited. Interventions co-designed with stroke survivors and delivered by telehealth are a potential solution.

AIM

The aim of this study is to test the feasibility, safety, and potential efficacy of a 6-month, telehealth-delivered PA and/or dietary (DIET) intervention.

METHODS

Pilot randomized trial. 80 adults with previous stroke who are living at home with Internet access and able to exercise will be randomized in a 2 × 2 factorial (4-arm) pilot randomized, open-label, blinded outcome assessment trial to receive PA, DIET, PA + DIET, or control interventions via telehealth. The PA intervention aims to support participants to meet the minimum recommended levels of PA (150 min/week moderate exercise), and the DIET intervention aims to support participants to follow the AusMed (Mediterranean-style) diet. The control group receives usual care plus education about PA and healthy eating. The co-primary outcomes are feasibility (proportion and characteristics of eligible participants enrolled and proportion of scheduled intervention sessions attended) and safety (adverse events) at 6 months. The secondary outcomes include recurrent stroke risk factors (blood pressure, physical activity levels, and diet quality), fatigue, mood, and quality of life. Outcomes are measured at 3, 6, and 12 months.

CONCLUSION

This trial will produce evidence for the feasibility, safety, and potential effect of telehealth-delivered PA and DIET interventions for people with stroke. Results will inform development of an appropriately powered trial to test effectiveness to reduce major risk factors for recurrent stroke.

TRIAL REGISTRATION

ACTRN12620000189921.

Device-measured physical activity and sedentary behaviour in relation to mental wellbeing: An analysis of the 1970 British cohort study

Although physical activity and sedentary behaviour have established associations with mental illness, the extent to which they impact on mental wellbeing is not well understood. We examined associations between moderate to vigorous physical activity (MVPA), sitting time (ST) and mental wellbeing in 4526 participants from the 1970 British Cohort Study (UK) in the age 46 survey (2016-18). MVPA and ST were measured using a thigh mounted accelerometer device (activPAL 3 micro) worn continuously for 7 days and participants completed the 14-item Warwick-Edinburg Mental Wellbeing Scale (WEMWBS) to assess mental wellbeing. In linear regression models MVPA (per hr) was associated with an additional 0.57 points on the WEMWBS (95% CI 0.03-1.12) regardless of gender, wear time, education, socioeconomic status, smoking, body mass index, disability and psychological distress. ST was not associated with WEMWBS in the adjusted models (B = -0.11, -0.23, 0.02). In MVPA stratified analyses, ST showed a linear trend with WEMBS in participants with low levels of MVPA but not in medium and high MVPA categories. In this large, nationally representative cohort, device-measured MVPA showed an association with higher mental wellbeing whilst ST was only associated with reduced mental wellbeing in participants with low levels of MVPA. Our main limitation was the cross-sectional design which precludes any inference of direction of association or causality. Nevertheless, interventions to promote MVPA may be an effective public health policy to promote mental wellbeing. Further investigation of the effect different sitting behaviours has on mental wellbeing is warranted.

A Cross-Sectional Analysis of Physical Activity Patterns, Aerobic Capacity and Perceptions about Exercise among Male Farmers in the Mid-West Region of Ireland

In Ireland, farmers have been identified as a high-risk population, with higher rates of cardiovascular disease (CVD) and overall mortality, compared with the general population. Farming has always been considered a physically active lifestyle. However, in recent times, with the increased use of technology and machinery, farmers may not be completing as much physical activity as before. There is a lack of research on physical activity patterns, fitness, and perception about exercise among farmers. Physical activity patterns were assessed using ActivPAL₃ micro monitors for a duration of 7 consecutive days. Aerobic capacity was measured using a validated sub-maximal exercise test to calculate Metabolic Equivalent Task (MET) levels. The Exercise Benefits and Barriers Scale (EBBS) questionnaire was used to explore perceived benefits and barriers towards exercise. Farmers completed a mean (standard deviation) of 16,452 (5,170) steps and 124 (43) minutes of moderate-vigorous intensity physical activity (MVPA) daily. The volume of weekly MVPA was largely accumulated in bouts lasting <10 minutes, with only 17.89% completing bouts of ≥10 minutes. Daily sitting time was 8.26 hours. Farmers are fit, have positive perceptions about exercise, and complete large quantities of physical activity, but not in a CVD protective pattern. CVD risk can be reduced in this population by encouraging them to sit less and engage in MVPA in bouts of ≥10 minutes, in line with current guidelines.

Time in Nature Associated with Decreased Fatigue in UK Truck Drivers

Heavy goods vehicle (HGV) driving is recognised as a highly hazardous occupation due to the long periods of sedentary behaviour, low levels of physical activity and unhealthy food options when working. These risk factors combine with shift work and concomitant irregular sleep patterns to increase the prevalence of fatigue. Fatigue is closely linked with stress and, subsequently, poor physiological and psychological health. In parallel, a wealth of evidence has demonstrated the health and wellbeing benefits of spending time in nature. Here, we sought to examine whether spending time in nature was associated with lower levels of fatigue, anxiety and depression in HGV drivers. 89 long-distance drivers (98.9% male, mean ± SD age: 51.0 ± 9 years, body mass index: 29.8 ± 4.7 kg/m²) participating in a wider health promotion programme reported time spent in nature (during and before the Covid-19 pandemic) and symptoms of occupational fatigue, depression and anxiety. After controlling for covariates, truck drivers who visited nature at least once a week exhibited 16% less chronic fatigue prior to the pandemic, and 23% less chronic fatigue and 20% less acute fatigue during the pandemic. No significant differences were observed for either anxiety or depression. As fatigue has a range of physical and mental health sequelae, we propose that increased exposure to natural settings may make a valuable contribution to interventions to promote the health and wellbeing of this underserved group.

Cross-sectional associations of device-measured sedentary behaviour and physical activity with cardio-metabolic health in the 1970 British Cohort Study

AIMS

This study aimed to examine the cross-sectional associations of thigh accelerometry-assessed sedentary behaviour and moderate-to-vigorous physical activity (MVPA) with cardio-metabolic health markers and prevalent diabetes in a population sample of middle-aged British adults.

METHODS

Participants (n = 4892) from the age-46-to-48 wave of the 1970 British Cohort Study were fitted with a waterproofed activPAL3 micro device. Total/prolonged sedentary time, breaks and MVPA were the main exposures. We dichotomized prolonged sedentary time and MVPA based on the corresponding median, generating four combinations as categorical exposures. Outcomes comprised of diabetes and seven cardio-metabolic health markers. We used logistic regression and generalized linear models to examine independent/joint associations, conducting a minimally adjusted model including demographics and contextual covariates, and further adjusted for total sedentary time and/or MVPA as applicable.

RESULTS

Each set of 10 sedentary breaks and 1 h of prolonged sedentary time were associated with HbA_1c (mmol/mol) [B = -0.18 (-0.33, -0.03) and 2.35 (1.01, 3.69), respectively]. Each set of 10 sedentary breaks and 1 h of MVPA were favourably associated with diabetes [adjusted odds ratio (AOR): 0.80 (0.71, 0.99) and 0.42 (0.26, 0.67), respectively]. Joint analyses showed that only the low MVPA × long sedentary time combination had significantly higher odds for diabetes than the referent high MVPA × short sedentary time combination [AOR: 1.89 (1.17, 3.03)].

CONCLUSIONS

Each set of additional 10 sedentary breaks per day was associated with 20% lower odds for diabetes. A low physical activity level combined with long sedentary time might synergistically deteriorate cardio-metabolic health.

Validity of a Non-Proprietary Algorithm for Identifying Lying Down Using Raw Data from Thigh-Worn Triaxial Accelerometers

Body postural allocation during daily life is important for health, and can be assessed with thigh-worn accelerometers. An algorithm based on sedentary bouts from the proprietary ActivePAL software can detect lying down from a single thigh-worn accelerometer using rotations of the thigh. However, it is not usable across brands of accelerometers. This algorithm has the potential to be refined. Aim: To refine and assess the validity of an algorithm to detect lying down from raw data of thigh-worn accelerometers. Axivity-AX3 accelerometers were placed on the thigh and upper back (reference) on adults in a development dataset (n = 50) and a validation dataset (n = 47) for 7 days. Sedentary time from the open Acti4-algorithm was used as input to the algorithm. In addition to the thigh-rotation criterion in the existing algorithm, two criteria based on standard deviation of acceleration and a time duration criterion of sedentary bouts were added. The mean difference (95% agreement-limits) between the total identified lying time/day, between the refined algorithm and the reference was +2.9 (−135,141) min in the development dataset and +6.5 (−145,159) min in the validation dataset. The refined algorithm can be used to estimate lying time in studies using different accelerometer brands.

Cultural adaptation, translation and validation of the Spanish version of Past-day Adults' Sedentary Time

Background

To better understand sedentary behaviour and favour international comparisons, more evidence from different countries are needed. However, there are a few tools available in Spanish to measure sedentary behaviour. This study aimed to culturally adapt, translate and validate the Past-day Adults’ Sedentary Time (PAST) questionnaire in Chilean adults compared with the ActivPAL.

Method

One hundred one workers wore an ActivPAL for 1 week and were asked to respond to the Spanish version of the PAST twice on different visits at a 7-day interval. The PAST assesses sedentary behaviour in several domains, including working time, during the previous day. Reliability was assessed with the intraclass correlation coefficient (ICC). Correlations and Bland-Altman methods were used to determine accuracy properties of the PAST compared with the ActivPAL.

Results

Seventy-seven participants provided valid data (51.0% male; age = 39.0 ± 12.39 years). The PAST showed moderate reliability (ICC = 0.63). For the total time in sedentary behavior per day, the PAST showed no correlation (r = 0.21, p = 0.07) and a mean bias of 54.9 min/day (LoA 95%: − 484.3, 594.2 min/day) with the ActivPAL. For the total time in SB at work, the PAST showed moderate reliability (ICC = 0.40), weak correlation (r = 0.37, p < 0.002), and mean bias was 33.8 min/day (LoA 95%: − 285.7, 353.3 min/day).

Conclusions

The PAST performed better when estimating sedentary behaviour during working hours compared with the whole day. In this setting, accuracy properties were comparable with other self-report tools.

Childhood Obesity and Device-Measured Sedentary Behavior: An Instrumental Variable Analysis of 3,864 Mother-Offspring Pairs

OBJECTIVE

Intergenerational data on mother-offspring pairs were utilized in an instrumental variable analysis to examine the longitudinal association between BMI and sedentary behavior.

METHODS

The sample included 3,864 mother-offspring pairs from the 1970 British Cohort Study. Height and weight were recorded in mothers (age 31 [5.4] years) and offspring (age 10 years) and repeated in offspring during adulthood. Offspring provided objective data on sedentary behavior (7-day thigh-worn activPAL) in adulthood at age 46 to 47 years.

RESULTS

Maternal BMI, the instrumental variable, was associated with offspring BMI at age 10 (change per kg/m² , β = 0.11; 95% CI: 0.09 to 0.12), satisfying a key assumption of instrumental variable analyses. Offspring (change per kg/m² , β = 0.010; 95% CI: -0.02 to 0.03 h/d) and maternal BMI (β = 0.017; 95% CI: 0.001 to 0.03 h/d) was related to offspring sedentary time, suggestive of a causal impact of BMI on sedentary behavior (two-stage least squares analysis, β = 0.18 [SE 0.08], P = 0.015). For moderate-vigorous physical activity, there were associations with offspring BMI (β = -0.010; 95% CI: -0.017 to -0.004) and maternal BMI (β = -0.007; 95% CI: -0.010 to -0.003), with evidence for causality (two-stage least squares analysis, β = -0.060 [SE 0.02], P = 0.001).

CONCLUSIONS

There is strong evidence for a causal pathway linking childhood obesity to greater sedentary behavior.

Comparing the activPAL software's Primary Time in Bed Algorithm against Self-Report and van der Berg's Algorithm

The purpose of this study was to compare activPAL algorithm-estimated values for time in bed (TIB), wake time (WT) and bedtime (BT) against self-report and an algorithm developed by van der Berg and colleagues. Secondary analyses of baseline data from the Community Activity for Prevention Study (CAPS) were used in which adults ≥ 18 years wore the activPAL for seven days. Mixed-effects models compared differences between TIB, WT, and BT for all three methods. Bland-Altman plots examined agreement and the two-one-sided test examined equivalence. activPAL was not equivalent to self-report or van der Berg in estimating TIB, but was equivalent to self-report for estimating BT, and was equivalent to van der Berg for estimating WT. The activPAL algorithm requires adjustments before researchers can use it to estimate TIB. However, researchers can use activPAL's option to manually enter self-reported BT and WT to estimate TIB and better understand 24-hour movement patterns.

Patterns of Sitting, Standing, and Stepping After Lower Limb Amputation

OBJECTIVE

The objectives of this study were to describe sitting, standing, and stepping patterns for people with lower limb amputation (LLA) and to compare sitting, standing, and stepping between people with dysvascular LLA and people with traumatic LLA.

METHODS

Participants with dysvascular or traumatic LLA were included if their most recent LLA was at least 1 year earlier, they were ambulating independently with a prosthesis, and they were between 45 and 88 years old. Sitting, standing, and stepping were measured using accelerometry. Daily sitting, standing, and stepping times were expressed as percentages of waking time. Time spent in bouts of specified durations of sitting (<30, 30-60, 60-90, and >90 minutes), standing (0-1, 1-5, and >5 minutes), and stepping (0-1, 1-5, and >5 minutes) was also calculated.

RESULTS

Participants (N = 32; mean age = 62.6 [SD = 7.8] years; 84% men; 53% with dysvascular LLA) spent most of the day sitting (median = 77% [quartile 1 {Q1}-quartile 3 {Q3} = 67%-84%]), followed by standing (median = 16% [Q1-Q3 = 12%-27%]) and stepping (median = 6% [Q1-Q3 = 4%-9%]). One-quarter (median = 25% [Q1-Q3 = 16%-38%]) of sitting was accumulated in bouts of >90 minutes, and most standing and stepping was accrued in bouts of <1 minute (standing: median = 42% [Q1-Q3 = 34%-54%]; stepping: median = 98% [Q1-Q3 = 95%-99%]). Between-etiology differences included proportion of time sitting (traumatic: median = 70% [Q1-Q3 = 59%-78%]; dysvascular: median = 79% [Q1-Q3 = 73%-86%]) and standing (traumatic: median = 23% [Q1-Q3 = 16%-32%]; dysvascular: median = 15% [Q1-Q3 = 11%-20%]).

CONCLUSION

Participants had high daily volumes of long durations of sitting. Further, these individuals accumulated most physical activity in bouts of <1 minute.

IMPACT

High levels of sedentary behavior and physical inactivity patterns may place people with LLA at greater mortality risk relative to the general population. Interventions to minimize sedentary behaviors and increase physical activity are potential strategies for improving poor outcomes of physical therapy after LLA.

Rise and Recharge: Effects on Activity Outcomes of an e-Health Smartphone Intervention to Reduce Office Workers' Sitting Time

This feasibility study evaluated the effects of an individual-level intervention to target office workers total and prolonged sedentary behaviour during working hours, using an e-health smartphone application. A three-arm (Prompt-30 or 60 min Intervention arm and a No-Prompt Comparison arm), quasi-randomised intervention was conducted over 12 weeks. Behavioural outcomes (worktime sitting, standing, stepping, prolonged sitting, and physical activity) were monitored using accelerometers and anthropometrics measured at baseline, 6 weeks and 12 weeks. Cardiometabolic measures were taken at baseline and 12 weeks. Fifty-six office workers (64% female) completed baseline assessments. The Prompt-60 arm was associated with a reduction in occupational sitting time at 6 (-46.8 min/8 h workday [95% confidence interval = -86.4, -6.6], p < 0.05) and 12 weeks (-69.6 min/8 h workday [-111.0, -28.2], p < 0.05) relative to the No-Prompt Comparison arm. Sitting was primarily replaced with standing in both arms (p > 0.05). Both Intervention arms reduced time in prolonged sitting bouts at 12 weeks (Prompt-30: -27.0 [-99.0, 45.0]; Prompt-60: -25.8 [-98.4, 47.4] min/8 h workday; both p > 0.05). There were no changes in steps or cardiometabolic risk. Findings highlight the potential of a smartphone e-health application, suggesting 60 min prompts may present an optimal frequency to reduce total occupational sedentary behaviour.

Objective and subjective measurement of sedentary behavior in human adults: A toolkit

OBJECTIVES

Objectives: Human biologists are increasingly interested in measuring and comparing physical activities in different societies. Sedentary behavior, which refers to time spent sitting or lying down while awake, is a large component of daily 24 hours movement patterns in humans and has been linked to poor health outcomes such as risk of all-cause and cardiovascular mortality, independently of physical activity. As such, it is important for researchers, with the aim of measuring human movement patterns, to most effectively use resources available to them to capture sedentary behavior.

METHODS

This toolkit outlines objective (device-based) and subjective (self-report) methods for measuring sedentary behavior in free-living contexts, the benefits and drawbacks to each, as well as novel options for combined use to maximize scientific rigor. Throughout this toolkit, emphasis is placed on considerations for the use of these methods in various field conditions and in varying cultural contexts.

RESULTS

Objective measures such as inclinometers are the gold-standard for measuring total sedentary time but they typically cannot capture contextual information or determine which specific behaviors are taking place. Subjective measures such as questionnaires and 24 hours-recall methods can provide measurements of time spent in specific sedentary behaviors but are subject to measurement error and response bias.

CONCLUSIONS

We recommend that researchers use the method(s) that suit the research question; inclinometers are recommended for the measurement of total sedentary time, while self-report methods are recommended for measuring time spent in particular contexts of sedentary behavior.

Using an e-Health Intervention to Reduce Prolonged Sitting in UK Office Workers: A Randomised Acceptability and Feasibility Study

Low-cost workplace interventions are required to reduce prolonged sitting in office workers as this may improve employees’ health and well-being. This study aimed to assess the acceptability and feasibility of an e-health intervention to reduce prolonged sitting among sedentary UK-based office workers. Secondary aims were to describe preliminary changes in employee health, mood and work productivity after using an e-health intervention. Healthy, university office workers (n = 14) completed this study. An 8 week randomised crossover design was used, consisting of two trials: Intervention (computer-based prompts) and Control. Eligibility and retention rates were recorded to assess the feasibility of the trial and interviews were conducted following the intervention to explore its acceptability. Sitting, standing and stepping were objectively assessed prior to and during week 8 of each trial. Before and after each trial, measurements of vascular function, cerebrovascular function, mood and work productivity were obtained. This study had eligibility and retention rates of 54.5% and 77.8%, respectively. Participants expressed a lack of autonomy and disruption to their workflow when using the e-health intervention, raising concerns over its acceptability and long-term implementation. Preliminary data indicate that the intervention may improve the patterning of activity accrued during work hours, with increases in the number of standing and stepping bouts completed, in addition to improving vascular function. This e-health intervention is feasible to deliver in a cohort of university office workers. However, adaptations to its implementation, such as personalised settings, are needed to increase acceptability before larger trials can be conducted.

The accumulation of, and associations between, nurses' activity levels within their shift in the emergency department

The aim of this study was to examine emergency nurses' activity levels and associations between hourly activity levels within-shifts. Fifty emergency nurses (45 females, 5 males) wore ActiGraph accelerometers and completed work diaries for up to 4 weeks. A sub-group (n = 42) also wore activPALs. Multilevel analyses examined temporal associations between hourly periods. In any hourly period, increased time spent in moderate- to vigorous-intensity physical activity (MVPA) was associated with less time spent in MVPA in the following hourly period. In any afternoon hourly period, increased time spent in MVPA was associated with more time spent in light-intensity physical activity in the following hourly period. No other associations were significant. Emergency nurses maintain activity levels within-shifts, except when more time spent in MVPA was associated with less time spent in MVPA in the following hour; a potential recovery strategy. Future research should determine how emergency nurses maintain their activity levels within-shifts. Practitioner Summary: Emergency nursing is physically demanding; however, it is unknown how active they are during hourly periods within-shifts. Emergency nurses' activity levels were maintained within hourly periods of a shift. Except for an increase in MVPA in 1 h was associated with a decrease in MVPA in the following hour. Abbreviations: CPR: cardiopulmonary resusitation; LPA: light-intensity physical activity; MPA: moderate-intenisty physical activity; MVPA: moderate- to vigorous-intensity physical activity; SED: sedentary.

Does sedentary time increase in older adults in the days following participation in intense exercise?

BACKGROUND

Older adults have the highest sedentary time across all age groups, and only a small portion is meeting the minimum recommendations for weekly physical activity. Little research to date has looked at how changes in one of these behaviours influences the other.

AIM

To assess changes in 24-h movement behaviours (sedentary time, light intensity physical activity (LPA), moderate-vigorous PA (MVPA) and sleep) over three consecutive days, following acute bouts of exercise of varying intensity in older adults.

METHODS

Participants (n = 28, 69.7 ± 6.5 years) completed a maximal exercise test and the following exercise protocols in random order: moderate continuous exercise (MOD), high-intensity interval exercise (HI) and sprint interval exercise (SPRT). A thigh-worn device (ActivPAL™) was used to measure movement behaviours at baseline and the 3 days following each exercise session.

RESULTS

Repeated measures analysis of variance indicated that compared to baseline, participants decreased MVPA in the 3 days following all exercise sessions and decreased LPA following HI and SPRT (p < 0.05). Over half of the sample had clinically meaningful increases in sedentary time (30 min/day) in the days following exercise participation.

DISCUSSION

Older adults who compensate for exercise participation by reducing physical activity and increasing sedentary time in subsequent days may require behavioural counseling to ensure that incidental and recreational physical activities are not reduced.

CONCLUSION

It appears that older adults compensate for acute exercise by decreasing MVPA and LPA, and increasing sedentary time in the days following exercise. Future research is needed to determine whether compensation persists with regular engagement.

Associations of sitting and physical activity with grip strength and balance in mid-life: 1970 British Cohort Study

Strength and balance training are now recommended in many physical activity (PA) guidelines. However, it is unclear whether these recommendations are applicable to middle-aged adults. We aimed to examine the associations of sitting and physical activity times with grip strength and standing balance performance in mid-life. Up to 4726 participants from the 1970 British Cohort study, with data on sitting and activity (measured using a thigh-worn accelerometer (activPAL3-micro)), grip strength and balance times at age 46 years were included in analyses. Associations of sitting, moderate-vigorous, and total PA times with grip strength and balance performance were tested using linear and multinomial logistic regression models, respectively. Greater time spent sitting was associated with weaker grip strength even after adjustment for potential confounders and MVPA time (fully adjusted regression coefficient: -0.51 kg (95% CI: -0.63, -0.39) per 1-hour sitting/day). Associations of PA time with grip strength were not independent of sitting time. There was only a weak association between sitting time and balance performance but greater MVPA and total PA times were associated with higher relative risks of successfully balancing for 30 seconds with eyes closed (vs poor balance). However, these associations were fully attenuated after adjustments for covariates. In summary, among a sample of middle-aged adults a robust association between sitting time and grip strength was observed. These findings suggest potential benefits of actively promoting less sitting alongside activities that specifically benefit muscle strength and balance performance in mid-life to ensure that people maintain all important aspects of their physical capability as they age.

Is Sitting Always Inactive and Standing Always Active? A Simultaneous Free-Living activPal and ActiGraph Analysis

Sedentary Behavior (SB), defined as sitting with minimal physical activity, is an emergent public health topic. However, the measurement of SB considers either posture (e.g., activPal) or physical activity (e.g., ActiGraph), and thus neglects either active sitting or inactive standing. The aim of this study was to determine the true amount of active sitting and inactive standing in daily life, and to analyze by how much these behaviors falsify the single sensors' sedentary estimates. Sedentary time of 100 office workers estimated with activPal and ActiGraph was therefore compared with Bland-Altman statistics to a combined sensor analysis, the posture and physical activity index (POPAI). POPAI classified each activPal sitting and standing event into inactive or active using the ActiGraph counts. Participants spent 45.0% [32.2%-59.1%] of the waking hours inactive sitting (equal to SB), 13.7% [7.8%-21.6%] active sitting, and 12.0% [5.7%-24.1%] inactive standing (mean [5th-95th percentile]). The activPal overestimated sedentary time by 30.3% [12.3%-48.4%] and the ActiGraph by 22.5% [3.2%-41.8%] (bias [95% limit-of-agreement]). The results showed that sitting is not always inactive, and standing is not always active. Caution should therefore be paid when interpreting the activPal (ignoring active sitting) and ActiGraph (ignoring inactive standing) measured time as SB.

Sedentary behaviour in cardiovascular disease patients: Risk group identification and the impact of cardiac rehabilitation

BACKGROUND

Sedentary behaviour (SB) is potentially an important target to improve cardiovascular health. This study 1) compared SB between cardiovascular disease (CVD) patients and age-matched controls, 2) identified characteristics associated with high SB levels, and 3) determined the impact of contemporary cardiac rehabilitation (CR) on SB.

METHODS

For objective 1, we recruited 131 CVD patients and 117 controls. All participants were asked about their general characteristics and medical history. SB was assessed by an objective accelerometer (activPAL3 micro). For objective 2, 2584 CVD patients were asked to fill in a questionnaire about their general characteristics, lifestyle, medical history and their SB. For objective 3, 131 CVD patients were followed over time and measured, pre-, directly post- and 2 months post-CR.

RESULTS

Objective 1. CVD patients spent 10.4 h/day (Q25 9.5; Q75 11.2) sedentary which was higher compared to healthy controls (9.4 h/day [Q25 8.4; Q75 10.29]). Objective 2. CVD patients being male, single or divorced, employed, physically inactive, reporting high alcohol consumption, living in an urban environment, having comorbidities and cardiac anxiety demonstrated a greater odds for large amounts of SB. Objective 3. The CR program significantly reduced sedentary time (-0.4 h/day [95%CI -0.7; -0.1]), which remained lower at 2-months post-CR (-0.3 h/day [95%CI -0.6; -0.03]).

CONCLUSIONS

CVD patients had greater amounts of objectively measured sedentary time compared to healthy controls. Sedentarism was associated with personal- and lifestyle characteristics, and comorbidities. Participation in a contemporary CR program slightly reduced sedentary time, but tailored interventions are needed to target SB in CVD patients.