The validation of a novel activity monitor in the measurement of posture and motion during everyday activities

Development of wearable posture monitoring system for dynamic assessment of sitting posture

There have been increasing cases of people seeking treatment for neck and back pain. The most common cause of neck and back pain is due to long-term poor sitting posture. The most common poor sitting posture cases are humpback, and head and neck being too far forward. It is easy to cause neck and back pain and other symptoms. Therefore, the development of wearable posture monitoring system for dynamic assessment of sitting posture becomes both helpful and necessary. In addition to recording the wearer's posture when sitting with quantitative assessment, it is needed to execute real-time action feedback for correctness of posture, in order to reduce neck and back pain due to long-term poor sitting posture. This study completed an instant recording and dynamic assessment of position measurement and feedback system. The system consists of a number of dynamic measurement units that can describe the posture trajectory, which integrates three-axis gyro meter, three-axis accelerometer, and magnetometer in order to measure the dynamic tracking. In the reliability analysis experiment, angle measurement error is less than 2%. The correlation coefficient between correlation analysis and Motion Analysis (MA) is 0.97. It is shown that the motion trajectory of this system is highly correlated with MA. In the feasibility test of sitting position detection, it is possible to detect the sitting position from the basic action of the walking, standing, sitting and lying down, and the sensitivity reaches 95.84%. In the assessment of the sitting position, the information published by the Canadian Centre for Occupational Health and Safety was used, as well as the recommendations of professional physicians as a basis for evaluating the threshold of the sitting measurement parameters and immediately feedback to the subjects. The system developed in this study can be helpful to reduce neck and back pain due to long-term poor sitting posture.

Sitting/lying time is associated with waist-to-hip increase but not with body weight increase or blood cardiovascular risk factors changes in adult women living in social vulnerability: A 2-year longitudinal study

OBJECTIVE

The present study aimed to determine whether physical activity and energy intake are associated with the anthropometric and blood cardiovascular risk factors alterations in women living in social vulnerability for a period of 2 years.

METHODS

The study was carried out with women residing in the outskirts of Maceió-AL, aged between 19 and 45 years. We characterized the socioeconomic and biochemical profile (glucose, insulin, and blood lipids) at the beginning and at the end of the study. Anthropometric evaluation was performed in three moments: at the beginning, and after 1 and 2 years of follow-up. Energy expenditure, measured by doubly labeled water, physical activity, measured by 7-day triaxial accelerometry, and energy intake, measured by 3-day 24-hour food recall, were collected at baseline.

RESULTS

After 2 years, 34 women were completely assessed, with a mean age of 33.7 years. Women spent around 16 hours of the day sitting/lying down. There was an increase in body weight (from 64.61 ± 11.69 to 66.37 ± 13.26 kg, P < .01), which was not associated with any of the predictors. There was also an increase in waist/hip ratio (WHR) (from 0.84 ± 0.07 to 0.87 ± 0.05, P < .01), which was positively associated with the amount of sitting/lying time per day. There were no significant alterations in blood cardiovascular risk factors.

CONCLUSION

Energy intake did not predict anthropometrical changes. Sitting/lying time was associated with an increase in WHR, but not in body weight or blood cardiovascular risk factors in low-income women.

Effect of Using a Wheeled Walker on Physical Activity and Sedentary Time in People with Chronic Obstructive Pulmonary Disease: A Randomised Cross-Over Trial

PURPOSE

To determine the effects of providing a wheeled walker (WW) for use in the home and community, on daily physical activity (PA) and sedentary time (ST) in people with chronic obstructive pulmonary disease (COPD).

METHODS

A randomised cross-over study in which participants with COPD characterised by a 6-min walk distance ≤ 450 m, who had recently finished pulmonary rehabilitation, completed two 5-week phases. During one phase, participants were provided a WW to use, whereas during the other phase, the WW was not available. The order of the phases was randomised. For the final week of each phase, measures of PA and ST were collected using wearable devices and health-related quality of life was measured using the Chronic Respiratory Disease Questionnaire (CRDQ). Wheeled walker use was also measured using an odometer attached to the device.

RESULTS

17 participants [FEV₁ = median (interquartile range) 33 (25) % pred; ten males] aged mean (SD) 73 (9) years completed the study. Comparing the data collected when the WW was not available for use, the daily step count was greater (mean difference [MD] 707 steps/day (95% confidence interval [CI] 75 to 1340) and participants tended to report less dyspnoea during daily life (MD 0.5 points per item, 95% CI - 0.1 to 1.0) when WW was available. No differences were observed for ST, upright time or stepping time. The WW was used over 4504 m/week (95% CI 2746 to 6262).

CONCLUSION

These data demonstrated that, when provided to selected patients with COPD, WWs increased daily step count.

CLINICAL TRIAL REGISTRATION NUMBER

ACTRN12609000332224.

Change of Objectively-Measured Physical Activity during Geriatric Rehabilitation

This prospective study investigated feasibility and sensitivity of sensor-based physical activity (PA) measures to monitor changes in PA during geriatric rehabilitation and its relation to clinical parameters at admission. PA was routinely measured at day 2 and day 15 after admission in 647 patients (70.2% women, mean age = 82.0 (SD = 7.19) years) of a German geriatric hospital using a thigh-worn accelerometer. Clinical records were used to include age, Barthel Index, diagnosis, mobility, orientation and cognition. Mean values and 95% confidence intervals (95%-CI) of walking duration, walking bout duration and number of sit-to-stand transfers were calculated to quantify different domains of PA. All observed PA parameters improved during rehabilitation, regardless of age, diagnosis or physical and cognitive function at admission. Walking duration increased by 12.1 (95%-CI: 10.3; 13.8) min, walking bout duration by 2.39 (95%-CI: 1.77; 3.00) s, and number of sit-to-stand transfers by 7 (95%-CI: 5; 8). Floor and ceiling effects were not observed. Walking duration at day 2 as well as day 15 was continuously associated with Barthel Index and statistically significant improved for all levels of Barthel Index. In summary, this study showed that sensor-based PA monitoring is feasible to assess the individual progress in geriatric rehabilitation patients.

Fall Risk in Relation to Individual Physical Activity Exposure in Patients with Different Neurodegenerative Diseases: a Pilot Study

Falls in patients with neurodegenerative diseases (NDDs) have enormous detrimental consequences. A better understanding of the interplay between physical activity (PA) and fall risk might help to reduce fall frequency. We aimed to investigate the association between sensor-based PA and fall risk in NDDs, using "falls per individual PA exposure time" as a novel measure. Eighty-eight subjects (n = 31 degenerative ataxia (DA), n = 14 Parkinson's disease (PD), n = 12 progressive supranuclear palsy (PSP) and 31 healthy controls) were included in this pilot study. PA was recorded in free-living environments with three-axial accelerometers (activPAL™) over 7 days. Falls were prospectively assessed over 12 months. Fall incidence was calculated by (i) absolute number of falls per person years (py) and (ii) falls per exposure to individual PA. Absolute fall incidence was high in all three NDDs, with differing levels (DA, 9 falls/py; PD, 14 falls/py; PSP, 29 falls/py). Providing a more fine-grained view on fall risk, correction for individual exposure to PA revealed that measures of low walking PA were associated with higher fall incidence in all three NDDs. Additionally, higher fall incidence was associated with more sit-to-stand transfers in PD and longer walking bouts in PSP. Our results suggest that low walking PA is a risk factor for falls in DA, PD and PSP, indicating the potential benefit of increasing individual PA in these NDDs to reduce fall risk. Moreover, they show that correction for individual exposure to PA yields a more differentiated view on fall risk within and across NDDs.

Toward a precision behavioral medicine approach to addressing high-risk sun exposure: a qualitative analysis

OBJECTIVES

Precision behavioral medicine techniques integrating wearable ultraviolet radiation (UVR) sensors may help individuals avoid sun exposure that places them at-risk for skin cancer. As a preliminary step in our patient-centered process of developing a just-in-time adaptive intervention, this study evaluated reactions and preferences to UVR sensors among melanoma survivors.

MATERIALS AND METHODS

Early stage adult melanoma survivors were recruited for a focus group (n = 11) or 10-day observational study, which included daily wearing a UVR sensor and sun exposure surveys (n = 39). Both the focus group moderator guide and observational study exit interviews included questions on UVR sensing as a potential intervention strategy. These responses were transcribed and coded using an inductive strategy.

RESULTS

Most observational study participants (84.6%) said they would find information provided by UVR sensors to be useful to help them learn about how specific conditions (eg, clouds, location) impact sun exposure and provide in-the-moment alerts. Focus group participants expressed enthusiasm for UVR information and identified preferred qualities of a UVR sensor, such as small size and integration with other devices. Participants in both studies indicated concern that UVR feedback may be difficult to interpret and some expressed that a UVR sensor may not be convenient or desirable to wear in daily life.

DISCUSSION

Melanoma survivors believe that personalized UVR exposure information could improve their sun protection and want this information delivered in a method that is meaningful and actionable.

CONCLUSION

UVR sensing is a promising component of a precision behavioral medicine strategy to reduce skin cancer risk.

Oral modified release morphine for breathlessness in chronic heart failure: a randomized placebo-controlled trial

AIMS

Morphine is shown to relieve chronic breathlessness in chronic obstructive pulmonary disease. There are no definitive data in people with heart failure. We aimed to determine the effectiveness and cost-effectiveness of 12 weeks morphine therapy for the relief of chronic breathlessness in people with chronic heart failure compared with placebo.

METHODS AND RESULTS

Parallel group, double-blind, randomized, placebo-controlled, phase III trial of 20 mg daily oral modified release morphine was conducted in 13 sites in England and Scotland: hospital/community cardiology or palliative care outpatients. The primary analysis compared between-group numerical rating scale average breathlessness/24 hours at week 4 using a covariance pattern linear mixed model. Secondary outcomes included treatment-emergent harms (worse or new). The trial closed early due to slow recruitment, randomizing 45 participants [average age 72 (range 39-89) years; 84% men; 98% New York Heart Association class III]. For the primary analysis, the adjusted mean difference was 0.26 (95% confidence interval, -0.86 to 1.37) in favour of placebo. All other breathlessness measures improved in both groups (week 4 change-from-baseline) but by more in those assigned to morphine. Neither group was excessively drowsy at baseline or week 4. There were no between-group differences in quality of life (Kansas) or cognition (Montreal) at any time point. There was no exercise-related desaturation and no change between baseline and week 4 in either group. There was no change in vital signs at week 4. The natriuretic peptide measures fell in both groups but by more in the morphine group [morphine 2169 (1092, 3851) pg/mL vs. placebo 2851 (1694, 5437)] pg/mL. There was no excess serious adverse events in the morphine group. Treatment-emergent harms during the first week were more common in the morphine group; all apart from 1 were ≤ grade 2.

CONCLUSIONS

We could not answer our primary objectives due to inadequate power. However, we provide novel placebo-controlled medium-term benefit and safety data useful for clinical practice and future trial design. Morphine should only be prescribed in this population when other measures are unhelpful and with early management of side effects.

A randomized controlled trial of the effect of supervised progressive cross-continuum strength training and protein supplementation in older medical patients: the STAND-Cph trial

Background

During hospitalization, older adults (+ 65 years) are inactive, which puts them at risk of functional decline and loss of independence. Systematic strength training can prevent loss of functional performance and combining strength training with protein supplementation may enhance the response in muscle mass and strength. However, we lack knowledge about the effect of strength training commenced during hospitalization and continued after discharge in older medical patients. This assessor-blinded, randomized study investigated the effect of a simple, supervised strength training program for the lower extremities, combined with post-training protein supplementation during hospitalization and in the home setting for 4 weeks after discharge, on the effect on change in mobility in older medical patients.

Methods

Older medical patients (≥ 65 years) admitted acutely from their home to the Emergency Department were randomized to either standard care or supervised progressive strength training and an oral protein supplement during hospitalization and at home 3 days/week for 4 weeks after discharge. The primary outcome was between-group difference in change in mobility from baseline to 4 weeks after discharge assessed by the De Morton Mobility Index, which assesses bed mobility, chair mobility, static and dynamic balance, and walking. Secondary outcomes were 24-h mobility, lower extremity strength, gait speed, grip strength and activities of daily living.

Results

Eighty-five patients were randomized to an intervention group (N = 43) or a control group (N = 42). In the intervention group, 43% were highly compliant with the intervention. Our intention-to-treat analysis revealed no between-group difference in mobility (mean difference in change from baseline to 4 weeks, − 4.17 (95% CI − 11.09; 2.74; p = 0.24) nor in any of the secondary outcomes. The per-protocol analysis showed that the daily number of steps taken increased significantly more in the intervention group compared to the control group (mean difference in change from baseline to 4 weeks, 1033.4 steps (95% CI 4.1; 2062.7), p = 0.049, adjusted for mobility at baseline and length of stay; 1032.8 steps (95% CI 3.6; 2061.9), p = 0.049, adjusted for mobility at baseline, length of stay, and steps at baseline).

Conclusions

Simple supervised strength training for the lower extremities, combined with protein supplementation initiated during hospitalization and continued at home for 4 weeks after discharge was not superior to usual care in the effect on change in mobility at 4 weeks in older medical patients. For the secondary outcome, daily number of steps, high compliance with the intervention resulted in a greater daily number of steps. Less than half of the patients were compliant with the intervention indicating that a simpler intervention might be needed.

Trial registration

ClinicalTrials.gov, NCT01964482. Registered on 14 October 2013. Trial protocol PubMed ID (PMID), 27039381.

Effects of Vibrotactile Feedback on Sedentary Behaviors in Adults: A Pilot Randomized Controlled Trial

No effective and easily implemented intervention strategies for reducing sedentary behavior have been established. This pilot trial (UMIN000024372) investigated whether vibrotactile feedback reduces sedentary behavior. Twenty-six adults aged 30–69 years who were sedentary ≥8 h/day were randomly assigned to control (n = 13) or vibration (n = 13) groups. Participants wore a monitor 9 h daily for seven-day periods at baseline (week zero), during the intervention (weeks one, three, five, and seven), and after the intervention (week eight). During the eight-week intervention, vibration-group participants were notified by a vibration through the monitor whenever continuous sedentary time reached ≥30 min; they also received weekly reports of their sedentary patterns. Control-group participants did not receive feedback. The primary outcome was change in total sedentary time. Changes in longer bouts of sedentary time (≥35 min) were also assessed. No significant difference was found in the change in total sedentary time (control: −17.5 min/9 h, vibration: −9.1 min/9 h; p = 0.42). Although no significant differences were observed in sedentary time in longer bouts, vibration-group participants exhibited significantly lower sedentary time (–21.6 min/9 h, p = 0.045). Thus, vibration feedback does not appear to offer any advantages in reducing total sedentary time.

Application of an Ecological Momentary Assessment Protocol in a Workplace Intervention: Assessing Compliance, Criterion Validity, and Reactivity

BACKGROUND

Ecological momentary assessment (EMA) is a method of collecting behavioral data in real time. The purpose of this study was to examine EMA compliance, identify factors predicting compliance, assess criterion validity of, and reactivity to, using EMA in a workplace intervention study.

METHODS

Forty-five adults (91.1% female, 39.7 [9.6] y) were recruited for a workplace standing desk intervention. Participants received 5 surveys each day for 5 workdays via smartphone application. EMA items assessed current position (sitting/standing/stepping). EMA responses were time matched to objectively measured time in each position before and after each prompt. Multilevel logistic regression models estimated factors influencing EMA response. Cohen kappa measured interrater agreement between EMA-reported and device-measured position. Reactivity was assessed by comparing objectively measured sitting/standing/stepping in the 15 minutes before and after each EMA prompt using multilevel repeated-measures models.

RESULTS

Participants answered 81.4% of EMA prompts. Differences in compliance differed by position. There was substantial agreement between EMA-reported and device-measured position (κ = .713; P < .001). Following the EMA prompt, participants sat 0.87 minutes more than before the prompt (P < .01).

CONCLUSION

The use of EMA is a valid assessment of position when used in an intervention to reduce occupational sitting and did not appear to disrupt sitting in favor of the targeted outcome.

Lazy Sundays: role of day of the week and reactivity on objectively measured physical activity in older people

Background

The aim of this study was to assess the effect of day of the week and wearing a device (reactivity) on objectively measured physical activity (PA) in older people.

Methods

Walking duration as a measure for PA was recorded from 1333 German community-dwelling older people (≥65 years, 43.8% women) over 5 days using accelerometers (activPAL). Least-square means of PA with 95%-confidence intervals (95%-CI) from multi-level analysis were calculated for each day of the week and each measurement day (days after sensor attachment).

Results

Walking duration on Sundays was significantly lower compared to working days (Sunday vs. Monday-Friday: − 12.8 min (95%-CI: − 14.7; − 10.9)). No statistically significant difference compared to working days was present for Saturdays. The linear slope for measurement day and walking duration was marginal and not statistically significant.

Conclusions

Studies using PA sensors in older people should assess Sundays and working days to adequately determine the activity level of the participants.

Is sitting invisible? Exploring how people mentally represent sitting

Background

Growing evidence suggests that prolonged uninterrupted sitting can be detrimental to health. Much sedentary behaviour research is reliant on self-reports of sitting time, and sitting-reduction interventions often focus on reducing motivation to sit. These approaches assume that people are consciously aware of their sitting time. Drawing on Action Identification Theory, this paper argues that people rarely identify the act of sitting as ‘sitting’ per se, and instead view it as an incidental component of more meaningful and purposeful typically-seated activities.

Methods

Studies 1 and 2 explored whether people mentioned sitting in written descriptions of actions. Studies 3–5 compared preferences for labelling a typically desk-based activity as ‘sitting’ versus alternative action identities. Studies 6 and 7 used card-sort tasks to indirectly assess the prioritisation of ‘sitting’ relative to other action descriptions when identifying similar actions.

Results

Participants rarely spontaneously mentioned sitting when describing actions (Studies 1–2), and when assigning action labels to a seated activity, tended to offer descriptions based on higher-order goals and consequences of action, rather than sitting or other procedural elements (Studies 3–5). Participants primarily identified similarities in actions based not on sitting, but on activities performed while seated (e.g. reading; Studies 6–7).

Conclusion

‘Sitting’ is a less accessible cognitive representation of seated activities than are representations based on the purpose and implications of seated action. Findings suggest that self-report measures should focus on time spent in seated activities, rather than attempting to measure sitting time via direct recall. From an intervention perspective, findings speak to the importance of targeting behaviours that entail sitting, and of raising awareness of sitting as a potential precursor to attempting to reduce sitting time.

Agreement between the Apple Series 1, LifeTrak Core C200, and Fitbit Charge HR with Indirect Calorimetry for Assessing Treadmill Energy Expenditure

The purpose of this study was to examine agreement in energy expenditure between the Apple Series 1 Watch, LifeTrak Core C200, and Fitbit Charge HR with indirect calorimetry during various treadmill speeds in young adults. Participants were a sample of college-aged students (mean age = 20.1 (1.7) years; 13 females, 17 males). Participants completed six structured 10-minute exercise sessions on a treadmill with speeds ranging from 53.6 m·min^-1 to 187.7 m·min^-1. Indirect calorimetry was used as the criterion. Participants wore the Apple Watch, LifeTrak, and Fitbit activity monitors on their wrists. Group-level agreement was examined using equivalence testing, relative agreement was examined using Spearman's rho, and individual-level agreement was examined using Mean Absolute Percent Error (MAPE) and Bland-Altman Plots. Activity monitor agreement with indirect calorimetry was supported using the Apple Watch at 160.9 m·min^-1 (Mean difference = -2.7 kcals, 90% C.I.: -8.3 kcals, 2.8 kcals; MAPE = 11.9%; r_s = 0.64) and 187.7 m·min^-1 (Mean difference = 3.7 kcals, 90% C.I.: -2.2 kcals, 9.7 kcals; MAPE = 10.7%; r_s = 0.72) and the Fitbit at 187.7 m·min^-1 (Mean difference = -0.2 kcals, 90% C.I.: -8.8 kcals, 8.5 kcals; MAPE = 20.1%; r_s = 0.44). No evidence for statistical equivalence was seen for the LifeTrak at any speed. Bland-Altman Plot Limits of Agreement were narrower for the Apple Series 1 Watch compared to other monitors, especially at slower treadmill speeds. The results support the utility of the Apple Series 1 Watch and Fitbit Charge HR for assessing energy expenditure during specific treadmill running speeds in young adults.

Appetite Control Is Improved by Acute Increases in Energy Turnover at Different Levels of Energy Balance

BACKGROUND

Weight control is hypothesized to be improved when physical activity and energy intake are both high [high energy turnover (ET)].

OBJECTIVE

The impact of three levels of ET on short-term appetite control is therefore investigated at fixed levels of energy balance.

DESIGN

In a randomized crossover trial, 16 healthy adults (25.1 ± 3.9 y of age; body mass index, 24.0 ± 3.2 kg/m2) spent three daylong protocols for four times in a metabolic chamber. Four conditions of energy balance (ad libitum energy intake, zero energy balance, -25% caloric restriction, and +25% overfeeding) were each performed at three levels of ET (PAL 1.3 low, 1.6 medium, and 1.8 high ET; by walking on a treadmill). Levels of appetite hormones ghrelin, GLP-1, and insulin (total area under the curve) were measured during 14 hours. Subjective appetite ratings were assessed by visual analog scales.

RESULTS

Compared with high ET, low ET led to decreased GLP-1 (at all energy balance conditions: P < 0.001) and increased ghrelin concentrations (caloric restriction and overfeeding: P < 0.001), which was consistent with higher feelings of hunger (zero energy balance: P < 0.001) and desire to eat (all energy balance conditions: P < 0.05) and a positive energy balance during ad libitum intake (+17.5%; P < 0.001).

CONCLUSION

Appetite is regulated more effectively at a high level of ET, whereas overeating and consequently weight gain are likely to occur at low levels of ET. In contrast to the prevailing concept of body weight control, the positive impact of physical activity is independent from burning up more calories and is explained by improved appetite sensations.

Sedentary Behaviors in Today's Youth: Approaches to the Prevention and Management of Childhood Obesity: A Scientific Statement From the American Heart Association

This scientific statement is about sedentary behavior and its relationship to obesity and other cardiometabolic outcomes in youth. A deleterious effect of sedentary behavior on cardiometabolic health is most notable for screen-based behaviors and adiposity; however, this relation is less apparent for other cardiometabolic outcomes or when sedentary time is measured with objective movement counters or position monitors. Increasing trends of screen time are concerning; the portability of screen-based devices and abundant access to unlimited programming and online content may be leading to new patterns of consumption that are exposing youth to multiple pathways harmful to cardiometabolic health. This American Heart Association scientific statement provides an updated perspective on sedentary behaviors specific to modern youth and their impact on cardiometabolic health and obesity. As we reflect on implications for practice, research, and policy, what emerges is the importance of understanding the context in which sedentary behaviors occur. There is also a need to capture the nature of sedentary behavior more accurately, both quantitatively and qualitatively, especially with respect to recreational screen-based devices. Further evidence is required to better inform public health interventions and to establish detailed quantitative guidelines on specific sedentary behaviors in youth. In the meantime, we suggest that televisions and other recreational screen-based devices be removed from bedrooms and absent during meal times. Daily device-free social interactions and outdoor play should be encouraged. In addition, parents/guardians should be supported to devise and enforce appropriate screen time regulations and to model healthy screen-based behaviors.

Editor's Choice: Dual-process model of older adults' sedentary behavior: an ecological momentary assessment study

Objective: A 10-day ecological momentary assessment (EMA) study was conducted to test a dual-process model of older adults' sedentary behavior.Design: Older adults (n = 104, 60-98 years) answered 6 EMA questionnaires/day to assess conscious processes (i.e. momentary intentions, self-efficacy to limit sedentary behavior over the next two hours) and wore an activPAL accelerometer to measure sedentary behavior. Habit strength for sedentary behavior, a non-conscious process, was self-reported at an introductory session.Main outcome measure: Time spent sitting in the two hours after the EMA prompt.Results: Older adults engaged in less sedentary behavior on occasions when their intentions (b = -1.63, p = 0.02) and self-efficacy (b = -2.01, p = 0.003) to limit sedentary behavior were stronger than one's average level of intentions or self-efficacy, respectively; however, older adults' average level of intentions (b = -5.30, p = 0.05) or self-efficacy (b = 2.77, p = 0.27) to limit sedentary behavior were not associated with sedentary behavior. Older adults with stronger sedentary behavior habits engaged in greater sedentary behavior in the two hours following the EMA prompt (b = 2.04, p = 0.006).Conclusion: Sedentary behavior is regulated by conscious and non-conscious processes. Interventions targeting older adults' sedentary behavior should promote momentary intention formation and self-efficacy beliefs to limit sitting as well as content to disrupt habitual sedentary behavior.

Quantifying sit-to-stand and stand-to-sit transitions in free-living environments using the activPAL thigh-worn activity monitor

PURPOSE

Standing up, sitting down and walking require considerable effort and coordination, which are crucial indicators to rehabilitation (e.g. stroke), and in older populations may indicate the onset of frailty and physical and cognitive decline. Currently, there are few reports robustly quantifying sit-to-stand and stand-to-sit transitions in free-living environments. The aim of this study was to identify and quantify these transitions using the peak velocity of sit-to-stand and stand-to-sit transitions to determine if these velocities were different in a healthy cohort and a mobility-impaired population.

METHODS

Free-living sit-to-stand and stand-to-sit acceleration data were recorded from 21 healthy volunteers and 34 stroke survivors using activPAL3™ monitors over a one-week period. Thigh inclination velocity was calculated from these accelerometer data. Maximum velocities were compared between populations.

RESULTS

A total of 10,299 and 11,392 sit-to-stand and stand-to-sit transitions were recorded in healthy volunteers and stroke survivors, respectively. Healthy volunteers had significantly higher overall mean peak velocities for both transitions compared with stroke survivors [70.7°/s ± 52.2 versus 44.2°/s ± 28.0 for sit-to-stand, P < 0.001 and 74.7°/s ± 51.8 versus 46.0°/s ± 31.9 for stand-to-sit; P < 0.001]. Mean peak velocity of transition was associated with increased variation in peak velocity across both groups.

CONCLUSION

There were significant differences in the mean peak velocity of sit-to-stand and stand-to-sit transitions between the groups. Variation in an individual's mean peak velocity may be associated with the ability to perform these transitions. This method could be used to evaluate the effectiveness of interventions following injury such as stroke, as well as monitor decline in functional ability.

Sex does not influence impairments in popliteal endothelial-dependent vasodilator or vasoconstrictor responses following prolonged sitting

An acute bout of prolonged sitting (PS) impairs the popliteal artery flow-mediated dilation (FMD) response. Despite equivocal reductions in mean shear rate, young women demonstrate an attenuated decline in popliteal FMD versus young men. However, it is uncertain whether popliteal endothelial-dependent vasoconstrictor responses [low-flow-mediated constriction (L-FMC)] are similarly affected by PS and/or whether sex differences exist. We tested the hypothesis that women would have attenuated reductions in both popliteal FMD and L-FMC responses following an acute bout of PS. Popliteal FMD and L-FMC responses were assessed via duplex ultrasonography before and after a 3-h bout of PS. These responses were then compared between 10 men (24 ± 2 yr) and 10 women (23 ± 2 yr) with similar ( P > 0.13) levels of objectively measured habitual physical activity (via PiezoRx) and sedentary time (via activPAL). At baseline, men and women exhibited similar ( P > 0.46) popliteal FMD (4.8 ± 1.2 vs. 4.5 ± 0.6%) and L-FMC (–1.7 ± 1.0 vs. –1.9 ± 0.9%) responses. Both sexes experienced identical (group: P > 0.76; time: P < 0.001) PS-induced impairments in popliteal FMD (–2.8 ± 1.4 vs. –2.6 ± 0.9%) and L-FMC (1.3 ± 0.7% vs. 1.4 ± 0.7%). In young adults, sex did not influence the negative PS-induced FMD, L-FMC, or microvascular responses in the lower limb. As such, our findings suggest that young men and women are similarly susceptible to the acute negative vascular effects of PS. Future studies should extend these findings to older, less physically active adults and/or patients with vascular disease.

NEW & NOTEWORTHY We compared changes in popliteal artery endothelial function to a single 3-h bout of sitting between young men and women. Both groups exhibited similar endothelial-dependent vasodilation (i.e., flow-mediated dilation) and endothelial-dependent vasoconstrictor responses (i.e., low-flow-mediated constriction) at baseline and equivocal impairments in these measures of endothelial function following prolonged sitting. These findings demonstrate that acute impairments in conduit artery endothelial health associated with uninterrupted sitting are not influenced by sex in young, healthy adults.

Autonomic cardiovascular control changes in recent heart transplant recipients lead to physiological limitations in response to orthostatic challenge and isometric exercise

PURPOSE

Heart transplantation causes denervation of the donor heart, but the consequences for cardiovascular homeostasis remain to be fully understood. The present study investigated cardiovascular autonomic control at supine rest, during orthostatic challenge and during isometric exercise in heart transplant recipients (HTxR).

METHODS

A total of 50 HTxRs were investigated 7-12 weeks after transplant surgery and compared with 50 healthy control subjects. Continuous, noninvasive recordings of cardiovascular variables were carried out at supine rest, during 15 min of 60° head-up tilt and during 1 min of 30% of maximal voluntary handgrip. Plasma and urine catecholamines were assayed, and symptoms were charted.

RESULTS

At supine rest, heart rate, blood pressures and total peripheral resistance were higher, and stroke volume and end diastolic volume were lower in the HTxR group. During tilt, heart rate, blood pressures and total peripheral resistance increased less, and stroke volume and end diastolic volume decreased less. During handgrip, heart rate and cardiac output increased less, and stroke volume and end diastolic volume decreased less. Orthostatic symptoms were similar across the groups, but the HTxRs complained more of pale and cold hands.

CONCLUSION

HTxRs are characterized by elevated blood pressures and total peripheral resistance at supine rest as well as attenuated blood pressures and total peripheral resistance responses during orthostatic challenge, possibly caused by low-pressure cardiopulmonary baroreceptor denervation. In addition, HTxRs show attenuated cardiac output response during isometric exercise due to efferent sympathetic denervation. These physiological limitations might have negative functional consequences.

Exploring occupational standing activities using accelerometer-based activity monitoring

Prolonged standing at work is required by an estimated 60% of the employed population and is associated with a high prevalence of musculoskeletal disorders. 'Standing' is expected to encompass a range of activities of varying intensity. This study aimed to define a range of 'standing' work-based activities; and objectively explore differences between 'standing' occupations. The following movements were defined using a triaxial accelerometer (ActivPAL) through recordings of known movements (n  =  11): static standing, weight-shifting, shuffling, walking and sitting. Movements over a working day were defined for chefs (n  =  10), veterinary surgeons (n  =  7) and office workers (n  =  9). Despite veterinary surgeons and chefs spending a similar time in an upright posture, veterinary surgeons spent 62% of this time standing statically whereas chefs split their time between all the movements. Overall, this study provides the first attempt to define 'standing' activities, allowing the differentiation of activities between occupations spending similar periods of time upright. Practitioner Summary: This study identified a range of work-based 'standing' activities of varying intensity. Differences in activity were recorded between two occupations spending a similar time in an upright posture (veterinary surgeons and chefs). A broader definition of standing activities could be important when considering factors related to musculoskeletal disorders at work.

Lifestyle factors during acute Epstein-Barr virus infection in adolescents predict physical activity six months later

AIM

Acute Epstein-Barr virus (EBV) infection is a trigger of prolonged fatigue. This study investigated baseline predictors of physical activity six months after an acute EBV infection.

METHODS

A total of 200 adolescents (12-20 years old) with acute EBV infection were assessed for 149 possible baseline predictors and followed prospectively. In this exploratory study, we performed linear regression analysis to assess possible associations between baseline predictors and steps per day at six months.

RESULTS

In the final multiple linear regression model, physical activity six months after acute EBV infection was significantly and independently predicted by baseline physical activity (steps per day), substance use (alcohol and illicit drugs) and human growth hormone (adjusted R²  = 0.20).

CONCLUSION

Baseline physical activity, substance use and plasma growth hormone are independent predictors of physical activity six months after an acute EBV infection in adolescents, whereas markers of the infection and associated immune response do not seem to be associated with physical activity six months later.

Compliance and Practical Utility of Continuous Wearing of activPAL™ in Adolescents

PURPOSE

The aim of this study was to examine the factors that influence compliance and practical utility of a continuous wear protocols for activPAL™ among adolescents.

METHODS

Seven hundred and fifty-five (11-18 y; 50.6% girls) students wore the waterproof activPAL™ for 7 consecutive days. The effects of factors such as weather and practical strategies on compliance were assessed. Students were asked to note reasons for removing it in a log. After the 7-day period, students anonymously completed a practical utility questionnaire.

RESULTS

The final sample used to analyze compliance contained 588 available data points; 72.4% met the validity criteria, which were ≥4 valid days. Rainfall was inversely associated with total wear time, whereas using alcohol pads and cartoon stickers during the application were positively associated with total wear time. Sweating (25.2%) and skin irritation (39.0%) were the most reasons for 290 removal episodes by 235 students. The 131 questionnaires showed that 80.1% regarded the continuous wear period as too long and encountered problems, and 55% would rather not wear it again.

CONCLUSION

Rainy weather affected girls' compliance with the continuous wear protocol for activPAL™. Skin irritation and sweat-induced inadvertent drops caused removal. Future studies should investigate more user-friendly protocols.

Textured shoe insoles to improve balance performance in adults with diabetic peripheral neuropathy: study protocol for a randomised controlled trial

INTRODUCTION

Peripheral neuropathy is a major risk factor for falls in adults with diabetes. Innovative footwear devices which artificially manipulate the sensory environment at the feet, such as textured shoe insoles, are emerging as an attractive option to mitigate balance and walking problems in neuropathic populations. This study aims to explore whether wearing textured insoles for 4 weeks alters balance performance in adults with diabetic peripheral neuropathy.

METHODS AND ANALYSIS

A prospective, single-blinded randomised controlled trial with parallel groups will be conducted on 70 adults with diabetic peripheral neuropathy. Adults with a diagnosis of peripheral neuropathy (secondary to type 2 diabetes), aged ≥18 years, ambulant over 20 m (with/without an assistive device), will be recruited. Participants will be randomised to receive a textured insole (n=35) or smooth insole (n=35), to be worn for 4 weeks. During baseline and post intervention assessments, standing balance (foam/firm surface; eyes open/closed) and walking tasks will be completed barefoot, wearing standard shoes only, and two different insoles (smooth, textured). The primary outcome measure will be centre of pressure (CoP) velocity, with higher values indicating poorer balance. Secondary outcome measures include walking quality (gait velocity, base of support, stride length and double-limb support time), physical activity levels, foot sensation (light-touch pressure, vibration) and proprioception (ankle joint position sense), and other balance parameters (CoP path length, anteroposterior and mediolateral excursion). Patient-reported outcomes will be completed evaluating foot health, frequency of falls and fear of falling. Data will be analysed using a repeated measures mixed models approach (including covariates) to establish any differences between-groups, for all outcome measures, over the intervention period.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the institutional Human Research Ethics Committee (#2017000098). Findings will be disseminated at national and international conferences, through peer-reviewed journals, workshops and social media.

TRIAL REGISTRATION NUMBER

ACTRN12617000543381; Pre-results.

How to Measure Sedentary Behavior at Work?

Background: Prolonged sedentary behavior (SB) is associated with increased risk for chronic conditions. A growing number of the workforce is employed in office setting with high occupational exposure to SB. There is a new focus in assessing, understanding and reducing SB in the workplace. There are many subjective (questionnaires) and objective methods (monitoring with wearable devices) available to determine SB. Therefore, we aimed to provide a global understanding on methods currently used for SB assessment at work.

Methods: We carried out a systematic review on methods to measure SB at work. Pubmed, Cochrane, Embase, and Web of Science were searched for peer-reviewed English-language articles published between 1st January 2000 and 17th March 2019.

Results: We included 154 articles: 89 were cross-sectional and 65 were longitudinal studies, for a total of 474,091 participants. SB was assessed by self-reported questionnaires in 91 studies, by wearables devices in also 91 studies, and simultaneously by a questionnaire and wearables devices in 30 studies. Among the 91 studies using wearable devices, 73 studies used only one device, 15 studies used several devices, and three studies used complex physiological systems. Studies exploring SB on a large sample used significantly more only questionnaires and/or one wearable device.

Conclusions: Available questionnaires are the most accessible method for studies on large population with a limited budget. For smaller groups, SB at work can be objectively measured with wearable devices (accelerometers, heart-rate monitors, pressure meters, goniometers, electromyography meters, gas-meters) and the results can be associated and compared with a subjective measure (questionnaire). The number of devices worn can increase the accuracy but make the analysis more complex and time consuming.

Translating a "Stand Up and Move More" intervention by state aging units to older adults in underserved communities: Protocol for a randomized controlled trial

INTRODUCTION

As aging is associated with functional decline, preventing functional limitations and maintaining independence throughout later life has emerged as an important public health goal. Research indicates that sedentary behavior (prolonged sitting) is associated with functional loss and diminished ability to carry out activities of daily living. Despite many efforts to increase physical activity, which can be effective in countering functional loss, only an estimated 8% of older adults meet national physical activity guidelines. Thus, shifting the focus to reducing sitting time is emerging as a potential new intervention strategy but little research has been conducted in this area. With community support and funding, we developed and pilot tested a 4-week "Stand Up and Move More" intervention and found decreases in sedentary behavior, increases in physical activity, and improvements in mobility and vitality in a small sample of older adults. The purpose of this project is to expand upon these pilot results and examine the effectiveness and feasibility of translating a "Stand Up and Move More" intervention by State Aging Units to older adults in underserved communities. Eighty older adults from 4 counties across Wisconsin predominantly made up of rural older adults and older African American adults are randomly assigned to intervention (n = 40) or wait-list control (n = 40) groups. The intervention consists of 4 weekly sessions plus a refresher session at 8 weeks, and is delivered by community partners in each county. The sessions are designed to elicit ideas from older adults regarding how they can reduce their sitting time, help them set practical goals, develop action plans to reach their goals, and refine their plans across sessions to promote behavior change. Sedentary behavior, physical activity levels, functional performance, and health-related quality of life are assessed before and after the intervention to examine the effectiveness of the program. Feasibility of implementing the program by our community partners is assessed via semi-structured interviews. Strengths of this project include strong community collaborations and a high need given that the older adult population is projected to increase substantially in the next 15 years.

CONCLUSION

This project will provide an important step in developing effective strategies for maintaining independence in older adults through determining the feasibility and impact of a community-based intervention to break up sitting time.

Learning the Orientation of a Loosely-Fixed Wearable IMU Relative to the Body Improves the Recognition Rate of Human Postures and Activities

Features were developed which accounted for the changing orientation of the inertial measurement unit (IMU) relative to the body, and demonstrably improved the performance of models for human activity recognition (HAR). The method is proficient at separating periods of standing and sedentary activity (i.e., sitting and/or lying) using only one IMU, even if it is arbitrarily oriented or subsequently re-oriented relative to the body; since the body is upright during walking, learning the IMU orientation during walking provides a reference orientation against which sitting and/or lying can be inferred. Thus, the two activities can be identified (irrespective of the cohort) by analyzing the magnitude of the angle of shortest rotation which would be required to bring the upright direction into coincidence with the average orientation from the most recent 2.5 s of IMU data. Models for HAR were trained using data obtained from a cohort of 37 older adults (83.9 ± 3.4 years) or 20 younger adults (21.9 ± 1.7 years). Test data were generated from the training data by virtually re-orienting the IMU so that it is representative of carrying the phone in five different orientations (relative to the thigh). The overall performance of the model for HAR was consistent whether the model was trained with the data from the younger cohort, and tested with the data from the older cohort after it had been virtually re-oriented (Cohen's Kappa 95% confidence interval [0.782, 0.793]; total class sensitivity 95% confidence interval [84.9%, 85.6%]), or the reciprocal scenario in which the model was trained with the data from the older cohort, and tested with the data from the younger cohort after it had been virtually re-oriented (Cohen's Kappa 95% confidence interval [0.765, 0.784]; total class sensitivity 95% confidence interval [82.3%, 83.7%]).

Office workers' experiences of attempts to reduce sitting-time: an exploratory, mixed-methods uncontrolled intervention pilot study

BACKGROUND

Office workers typically sit for most of the workday, which has been linked to physical and mental ill-health and premature death. This mixed-methods study sought to identify barriers and facilitators to reducing sitting and increasing standing among office workers who received an intervention prototype (the 'ReSiT [Reducing Sitting Time] Study'). The intervention comprised a sit-stand workstation and tailored advice to enhance motivation, capability and opportunity to displace sitting with standing.

METHODS

Twenty-nine UK university office workers (aged ≥18y, working ≥3 days per week, most time spent at a seated desk) participated in a 13-week uncontrolled study. They were initially monitored for one-week. In a subsequent face-to-face consultation, participants received sitting time feedback from a prior one-week monitoring period, and selected from a set of tailored sitting-reduction techniques. Quantitative data comprising sitting, standing and stepping time, which were objectively monitored for 7 consecutive days across three post-intervention timepoints, were descriptively analysed. Qualitative data, from semi-structured interviews conducted at 1, 6 and 12-weeks post-intervention, were thematically analysed.

RESULTS

Compared to baseline, mean sitting time decreased at weeks 1, 6 and 12 by 49.7mins, 118.2mins, and 109.7mins respectively. Despite prior concerns about colleagues' reactions to standing, many reported encouragement from others, and standing could be equally conducive to social interaction or creating private, personal space. Some perceived less cognitively-demanding tasks to be more conducive to standing, though some found standing offered a valued break from challenging tasks. Participants prioritised workload over sitting reduction and were more likely to stand after rather than during work task completion. Temporary context changes, such as holidays, threatened to derail newfound routines.

CONCLUSIONS

Our findings emphasise the importance of understanding workers' mental representations of their work, and the social functions of sitting and standing in the workplace. Workplace intervention developers should incorporate a pre-intervention sitting time monitoring period, encourage workers to identify personally meaningful tasks and cues for standing, and build organisational support for sitting-reduction. We will use these insights to refine our intervention for self-administered delivery.

TRIAL REGISTRATION

ISRCTN29395780 (registered 21 November 2016).

Feasibility, acceptability and efficacy of a text message-enhanced clinical exercise rehabilitation intervention for increasing 'whole-of-day' activity in people living with and beyond cancer

Background

Exercise interventions are typically delivered to people with cancer and survivors via supervised clinical rehabilitation. However, motivating and maintaining activity changes outside of the clinic setting remains challenging. This study investigated the feasibility, acceptability and efficacy of an individually-tailored, text message-enhanced intervention that focused on increasing whole-of-day activity both during and beyond a 4-week, supervised clinical exercise rehabilitation program for people with cancer and survivors.

Methods

Participants (n = 36; mean ± SD age 64.8 ± 9.6 years; 44.1 ± 30.8 months since treatment) were randomized 1:1 to receive the text message-enhanced clinical exercise rehabilitation program, or the standard clinical exercise rehabilitation program alone. Activity was assessed at baseline, 4-weeks (end of the standard program) and 12-weeks (end of enhanced program) using both device (activPAL accelerometer; sitting, standing, light-stepping, moderate-stepping) and self-report [Multimedia Activity Recall for Children and Adults (MARCA); sedentary, light, moderate-to-vigorous physical activity (MVPA)] methods. The MARCA also assessed time use domains to provide context to activity changes. Changes and intervention effects were evaluated using linear mixed models, adjusting for baseline values and potential confounders.

Results

The study had high retention (86%) and participants reported high levels of satisfaction [4.3/5 (±0.8)] with the intervention. Over the first 4 weeks, MARCA-assessed MVPA increased [+ 53.2 (95%CI: 2.9, 103.5) min/d] between groups, favoring the text message-enhanced program, but there were no significant intervention effects on sedentary behavior. By 12 weeks, relative to the standard group, participants in the text message-enhanced group sat less [activPAL overall sitting: − 48.2 (− 89.9, − 5.6) min/16 h awake; MARCA: -80.1 (− 156.5, − 3.8) min/d] and were participating in more physical activity [activPAL light stepping: + 7.0 (0.4, 13.6: min/16 h awake; MARCA MVPA: + 67.3 (24.0, 110.6) min/d]. The time-use domains of Quiet Time [− 63.3 (− 110.5, − 16.0) min/d] and Screen Time [− 62.0 (− 109.7, − 14.2) min/d] differed significantly between groups.

Conclusions

Results demonstrate feasibility, acceptability and efficacy of a novel, text message-enhanced clinical exercise rehabilitation program to support changes in whole-of-day activity, including both physical activity and sedentary behavior. Changes were largely seen at 12-week follow-up, indicating potential for the intervention to result in continued improvement and maintenance of behavior change following a supervised exercise intervention.

Trial registration

This trial is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12616000641493; date registered 17/5/16).

Electronic supplementary material

The online version of this article (10.1186/s12889-019-6767-4) contains supplementary material, which is available to authorized users.

Objective measurement of sedentary time and physical activity in people with rheumatoid arthritis: protocol for an accelerometer and activPALTM validation study

BACKGROUND

The accurate measurement of sedentary time and physical activity in Rheumatoid Arthritis (RA) is critical to identify important health consequences and determinants of these behaviours in this patient group. However, objective methods have not been well-validated for measurement of sedentary time and physical activity in RA.

AIMS

Specific objectives are to: 1) validate the ActiGraph GT3X+ accelerometer and activPAL3μTM against indirect calorimetry and direct observation respectively, and define RA-specific accelerometer cut-points, for measurement of sedentary time and physical activity in RA; 2) validate the RA-specific sedentary time accelerometer cut-points against the activPAL3μTM; 3) compare sedentary time and physical activity estimates in RA, using RA-specific vs. widely-used non-RA accelerometer cut-points.

METHODS

Objective 1: People with RA will wear an ActiGraph GT3X+, activPAL3μTM, heart rate monitor and indirect calorimeter, whilst being video-recorded undertaking 11 activities representative of sedentary behaviour, and light and moderate intensity physical activity. Objectives 2 and 3: People with RA will wear an ActiGraph GT3X+ and activPAL3μTM for 7 days to measure free-living sedentary time and physical activity.

DISCUSSION

This will be the first study to define RA-specific accelerometer cut-points, and represents the first validation of the ActiGraph accelerometer and activPALTM, for measurement of sedentary time and physical activity in RA. Findings will inform future RA studies employing these devices, ensuring more valid assessment of sedentary time and physical activity in this patient group.

Week and Weekend Day Cadence Patterns Long-Term Post-Bariatric Surgery

Obesity can negatively influence walking cadence, reducing the overall intensity of daily activities and increasing the risk of weight gain.

PURPOSE

Objectively describe the walking cadence of individuals' long-term post-bariatric surgery.

METHODS

Fifty-eight participants, 51.2 ± 8.9 years old, with a BMI of 34.6 ± 10.1 kg/m², 10.0 ± 3.1 years post-surgery wore an activPAL accelerometer for 7 consecutive days. Data was analyzed using participants' current BMI, dichotomized by obesity status, < or ≥ 30 kg/m².

RESULTS

On average, participants walked 5124 ± 2549 steps/day on weekdays and 6097 ± 2786 steps/day on weekend days (p = .003). Participants spent the majority (75%) of their daily steps at a slow-walking average cadence (non-obese: week = 65.3 ± 5.0 steps/min and weekend = 63.8 ± 6.7 steps/min; obese: week = 67.8 ± 8.2 steps/min and weekend = 63.3 ± 6.9 steps/min), with no difference between groups for week or weekend days (p = .153 and .774). The cadence of participants with obesity was significantly lower on weekends compared to weekdays for walking events > 30 s (p = .002) and > 60 s (p = .008) in duration. Weekday cadence of participants without obesity was similar to weekend day cadence across all walking event durations. The majority of walking events occurred below 30 s in duration for all participants.

CONCLUSIONS

Long-term post-bariatric surgery, movement occurs in short duration bouts at a slow-walking cadence for the majority of movement. Individuals without obesity had similar movement patterns from week to weekend days while participants with obesity significantly lowered their cadence on weekend days.

The Behavioral Wellness in Pregnancy study: a randomized controlled trial of a multi-component intervention to promote appropriate weight gain

BACKGROUND

Adequate weight gain during pregnancy is important to both maternal and fetal outcomes. To date, randomized controlled trials have not been effective at increasing the proportion of women meeting gestational weight-gain guidelines.

OBJECTIVES

The aim of this study was to determine whether a multi-component behavioral intervention with a Registered Dietitian Nutritionist significantly improves the proportion of women who adhere to the 2009 Institute of Medicine weight-gain guidelines.

METHODS

Participants were randomly assigned to usual care (UC; n = 24) or intervention (n = 23) between 8 and 14 weeks of gestation. The intervention included a minimum of 6 one-on-one counseling sessions over ∼30 wk focusing on healthy diet and physical activity (PA) goals. In addition to the face-to-face visits, weekly communication via email supported healthy eating, PA, and appropriate weight gain. Gestational weight gain, PA, and diet were assessed at 8-14, 26-28, and 34-36 weeks of gestation; weight retention was measured 2 mo postpartum.

RESULTS

The proportion of women meeting the guidelines was significantly greater in those receiving the intervention than UC (60.8% compared with 25.0%, OR: 4.7; 95% CI: 1.3, 16.2; P = 0.019). Furthermore, 36.4% of the intervention women were at or below their prepregnancy weight at 2 mo postpartum compared with 12.5% in the UC group (P = 0.05).

CONCLUSIONS

A multi-component behavioral intervention improved adherence to the 2009 Institute of Medicine weight-gain guidelines. This trial was registered with clinicaltrials.gov as NCT02168647.

Feasibility and impact of sit-stand workstations with and without exercise in office workers at risk of low back pain: A pilot comparative effectiveness trial

The aim of this study was to compare the feasibility and impact of sit-stand workstations plus advice, with or without exercise, on back pain and sitting time in office workers at risk of low back pain (LBP). Eligible participants (n = 29/169; 17% overall) were randomized to receive a sit-stand workstation and advice with (n = 16) or without (n = 13) progressive resistance exercise training for 4-weeks. Feasibility (recruitment, acceptability, adherence) and impact (LBP severity during a standardized standing task, workplace-sitting time) were assessed. Intervention acceptability (87.5% very satisfied) was good and adherence (60% completed all 12 exercise sessions) was satisfactory. Maximum LBP severity (mean difference of -1.3 (-2.0, -0.6) and workplace sitting time (82.7-99.3 min/8-hr workday reduction) were similarly reduced in both groups. The introduction of a sit-stand workstation with advice was feasible and achieved similar outcomes for LBP and workplace sitting time when administered with or without exercise.

Daily step count of British military males with bilateral lower limb amputations: A comparison of in-patient rehabilitation with the consecutive leave period between admissions

BACKGROUND:

Reduced function and health in individuals with lower limb amputation is well documented. Step count measurement could facilitate rehabilitation and help monitor functional health outcomes.

OBJECTIVES:

To determine whether mean daily step count changed between in-patient rehabilitation and consecutive leave periods.

STUDY DESIGN:

Observational study.

METHODS:

Nine individuals with bilateral traumatic amputations attending rehabilitation at the Defence Medical Rehabilitation Centre during a 4-month period were invited to participate in the study (two bilateral transfemoral, two bilateral transfemoral/knee disarticulation, two transfemoral/transtibial, one bilateral transfemoral plus transradial, one bilateral transfemoral plus transhumeral and one transfemoral/transtibial/transradial). Prostheses worn by each participant were fitted with an activity monitor (LAM2^TM; PAL Technologies Ltd, Glasgow). Mean daily step count was analysed for each participant following 2 weeks in-patient rehabilitation and consecutive 2 weeks away from rehabilitation.

RESULTS:

Nine participants completed the study (time since injury: 19 ± 7 months, age: 26 ± 6 years). Mean daily step count significantly decreased from 2258 ± 192 during in-patient rehabilitation to 1387 ± 363 at home ( p < 0.01).

CONCLUSION:

The step count decreased when away from rehabilitation, confirming the hypothesis that the mean daily step count would change between in-patient rehabilitation and consecutive leave period.

CLINICAL RELEVANCE

These data provide an indication of the step count achievable by young, military male personnel with bilateral lower limb amputations and highlights differences between intensive in-patient rehabilitation and consecutive leave periods. It is suggested that further investigation and support of clinical monitoring could facilitate rehabilitation tailored to the individual.

Improving Hip-Worn Accelerometer Estimates of Sitting Using Machine Learning Methods

PURPOSE

This study aimed to improve estimates of sitting time from hip-worn accelerometers used in large cohort studies by using machine learning methods developed on free-living activPAL data.

METHODS

Thirty breast cancer survivors concurrently wore a hip-worn accelerometer and a thigh-worn activPAL for 7 d. A random forest classifier, trained on the activPAL data, was used to detect sitting, standing, and sit-stand transitions in 5-s windows in the hip-worn accelerometer. The classifier estimates were compared with the standard accelerometer cut point, and significant differences across different bout lengths were investigated using mixed-effect models.

RESULTS

Overall, the algorithm predicted the postures with moderate accuracy (stepping, 77%; standing, 63%; sitting, 67%; sit-to-stand, 52%; and stand-to-sit, 51%). Daily level analyses indicated that errors in transition estimates were only occurring during sitting bouts of 2 min or less. The standard cut point was significantly different from the activPAL across all bout lengths, overestimating short bouts and underestimating long bouts.

CONCLUSIONS

This is among the first algorithms for sitting and standing for hip-worn accelerometer data to be trained from entirely free-living activPAL data. The new algorithm detected prolonged sitting, which has been shown to be the most detrimental to health. Further validation and training in larger cohorts is warranted.

Impact of sit-stand desks at work on energy expenditure, sitting time and cardio-metabolic risk factors: Multiphase feasibility study with randomised controlled component

Uncertainties remain about the overall effect of sit-stand desks for reducing prolonged sitting among office-based workers. This study assessed the feasibility of a randomised controlled trial of the impact of workplace sit-stand desks on overall energy expenditure, sitting time and cardio-metabolic outcomes. It involved four phases: Phase I: online survey; Phase II: workspace auditing; Phase III: randomised intervention (provision of sit-stand desks at work for 3 months); Phase IV: qualitative component. Participants were offıce-based employees of two companies in Cambridge, England. Among Phase I participants interested in the trial, 100 were randomised to Phase II. Of those with workspaces suitable for sit-stand desks, 20 were randomised to Phase III. Those allocated to the intervention completed Phase IV. Outcomes included: trial participation interest, desk-type (full desks/desk mounts) and assessment location (work/laboratory/home) preferences (Phase I); proportion of workspaces permitting sit-stand desk installation (Phase II); energy expenditure, sitting time and cardio-metabolic outcomes (Phase III); study participation experiences (Phase IV). Data were collected between May 2015 and December 2016. Recruitment and trial implementation were feasible: 92% of survey respondents expressed participation interest; 80% of workspaces could accommodate sit-stand desks; assessments were done in workplaces, preferred by 71%. Sit-stand desk provision reduced workplace sitting time by 94 min/day (95% CI 17.7-170.7). Their impact on energy expenditure and cardio-metabolic outcomes is unclear. The results confirm the feasibility of a trial assessing sit-stand desks' impact on energy expenditure, sitting time and cardio-metabolic outcomes, which should reduce uncertainty concerning the intervention's potential to reduce the health risks of prolonged sitting. Trial registration ISRCTN44827407.

Physical Activity Energy Expenditure and Total Daily Energy Expenditure in Successful Weight Loss Maintainers

OBJECTIVE

The objective of this study was to compare physical activity energy expenditure (PAEE) and total daily energy expenditure (TDEE) in successful weight loss maintainers (WLM) with normal weight controls (NC) and controls with overweight/obesity (OC).

METHODS

Participants were recruited in three groups: WLM (n = 25, BMI 24.1 ± 2.3 kg/m² ; maintaining ≥ 13.6-kg weight loss for ≥ 1 year), NC (n = 27, BMI 23.0 ± 2.0 kg/m² ; similar to current BMI of WLM), and OC (n = 28, BMI 34.3 ± 4.8 kg/m² ; similar to pre-weight loss BMI of WLM). TDEE was measured using the doubly labeled water method. Resting energy expenditure (REE) was measured using indirect calorimetry. PAEE was calculated as (TDEE - [0.1 × TDEE] - REE).

RESULTS

PAEE in WLM (812 ± 268 kcal/d, mean ± SD) was significantly higher compared with that in both NC (621 ± 285 kcal/d, P < 0.01) and OC (637 ± 271 kcal/d, P = 0.02). As a result, TDEE in WLM (2,495 ± 366 kcal/d) was higher compared with that in NC (2,195 ± 521 kcal/d, P = 0.01) but was not significantly different from that in OC (2,573 ± 391 kcal/d).

CONCLUSIONS

The high levels of PAEE and TDEE observed in individuals maintaining a substantial weight loss (-26.2 ± 9.8 kg maintained for 9.0 ± 10.2 years) suggest that this group relies on high levels of energy expended in physical activity to remain in energy balance (and avoid weight regain) at a reduced body weight.

Dose-response between frequency of interruption of sedentary time and fasting glucose, the dawn phenomenon and night-time glucose in Type 2 diabetes

AIM

To explore the dose-response between frequency of interruption of sedentary time and basal glucose (fasting glucose, the dawn phenomenon and night-time glucose) in Type 2 diabetes.

METHODS

In a randomized three-treatment, two-period balanced incomplete block trial, 12 people with Type 2 diabetes (age, 60.0 ± 3.2 years; BMI, 30.2 ± 1.4 kg/m² ) completed two of three conditions: sitting for 7 h interrupted every 60 min (Condition 1), 30 min (Condition 2), and 15 min (Condition 3) by 3-min light-intensity walking breaks. The activPAL3 and FreeStyle Libre were used to assess physical activity/sedentary behaviour and continuous glucose profile. Standardized meals were provided, and changes in basal glucose of the nights and early mornings before and after treatment conditions were calculated (mean ± SE).

RESULTS

After treatment conditions, fasting glucose and duration of the dawn phenomenon were lower for Condition 3 (-1.0 ± 0.2 mmol/l, P < 0.02; -3.1 ± 1.3 h, P = 0.004) compared with Condition 1 (-0.1 ± 0.2 mmol/l; 1.9 ± 1.2 h). The magnitude of the dawn phenomenon was reduced in Condition 3 (-0.6 ± 0.4 mmol/l, P = 0.041) compared with Condition 2 (0.6 ± 0.3 mmol/l). Night-time glycaemic variability (coefficient of variation) was reduced in Condition 3 (-9.7 ± 3.9%) relative to Condition 2 (6.1 ± 4.8%, P < 0.03) and Condition 1 (2.5 ± 1.8%, P = 0.02). There was no change in night-time mean glucose.

CONCLUSIONS

Frequent interruptions of prolonged sitting with 3 min of light-intensity walking breaks every 15 min improves fasting glucose, the dawn phenomenon and night-time glycaemic variability, and this might be a simple therapeutic intervention to improve glucose control. Clinicaltrials.gov Identifier: NCT02738996.

The Dynamic Work study: study protocol of a cluster randomized controlled trial of an occupational health intervention aimed at reducing sitting time in office workers

Background

Large volumes of sitting time have been associated with multiple health risks. To reduce sitting time of office workers working for a Dutch insurance company, the Dynamic Work intervention was developed. The primary objective of this paper is to describe the study protocol of the Dynamic Work study, which aims to evaluate if this multicomponent intervention is (cost-)effective in reducing total sitting time on the short-term (≈3 months) and longer-term (≈12 months) compared to usual practice.

Methods/design

This two-arm cluster randomized controlled trial will recruit 250 desk-based office workers working at different locations of an insurance company in the Netherlands. After baseline measurements, departments will be matched in pairs and each pair will be randomly assigned to the control or intervention condition. The multicomponent intervention contains organizational (i.e. face to face session with the head of the department), work environmental (i.e. the introduction of sit-stand desks and cycling workstations), and individual elements (i.e. counselling and activity/sitting tracker with a self-help program booklet). The counselling involves two group intervention sessions and four on-site department consultations with an occupational physiotherapist. Sitting time (primary outcome), upright time and step counts will be assessed objectively using the activPAL activity monitor at baseline, short-term (approximately 3 months) and longer-term (12 months). Other outcomes will include: self-reported lifestyle behaviours, anthropometrics, work-related outcomes (i.e. absenteeism, presenteeism, work performance, work-related stress), health-related outcomes (i.e. vitality, musculoskeletal symptoms, need for recovery, quality of life), and costs from both company and societal perspective. The study will include economic and process evaluations.

Discussion

This study will assess the longer-term (cost-) effectiveness of a multicomponent workplace intervention aimed at reducing sitting time in comparison with usual practice. Furthermore, the process evaluation will provide insights in factors associated with successful implementation of this intervention.

Trial registration

ClinicalTrials.govNCT03115645; Registered 13 April 2017. Retrospectively registered.

The effect of a programme to improve men's sedentary time and physical activity: The European Fans in Training (EuroFIT) randomised controlled trial

BACKGROUND

Reducing sitting time as well as increasing physical activity in inactive people is beneficial for their health. This paper investigates the effectiveness of the European Fans in Training (EuroFIT) programme to improve physical activity and sedentary time in male football fans, delivered through the professional football setting.

METHODS AND FINDINGS

A total of 1,113 men aged 30-65 with self-reported body mass index (BMI) ≥27 kg/m2 took part in a randomised controlled trial in 15 professional football clubs in England, the Netherlands, Norway, and Portugal. Recruitment was between September 19, 2015, and February 2, 2016. Participants consented to study procedures and provided usable activity monitor baseline data. They were randomised, stratified by club, to either the EuroFIT intervention or a 12-month waiting list comparison group. Follow-up measurement was post-programme and 12 months after baseline. EuroFIT is a 12-week, group-based programme delivered by coaches in football club stadia in 12 weekly 90-minute sessions. Weekly sessions aimed to improve physical activity, sedentary time, and diet and maintain changes long term. A pocket-worn device (SitFIT) allowed self-monitoring of sedentary time and daily steps, and a game-based app (MatchFIT) encouraged between-session social support. Primary outcome (objectively measured sedentary time and physical activity) measurements were obtained for 83% and 85% of intervention and comparison participants. Intention-to-treat analyses showed a baseline-adjusted mean difference in sedentary time at 12 months of -1.6 minutes/day (97.5% confidence interval [CI], -14.3-11.0; p = 0.77) and in step counts of 678 steps/day (97.5% CI, 309-1.048; p < 0.001) in favor of the intervention. There were significant improvements in diet, weight, well-being, self-esteem, vitality, and biomarkers of cardiometabolic health in favor of the intervention group, but not in quality of life. There was a 0.95 probability of EuroFIT being cost-effective compared with the comparison group if society is willing to pay £1.50 per extra step/day, a maximum probability of 0.61 if society is willing to pay £1,800 per minute less sedentary time/day, and 0.13 probability if society is willing to pay £30,000 per quality-adjusted life-year (QALY). It was not possible to blind participants to group allocation. Men attracted to the programme already had quite high levels of physical activity at baseline (8,372 steps/day), which may have limited room for improvement. Although participants came from across the socioeconomic spectrum, a majority were well educated and in paid work. There was an increase in recent injuries and in upper and lower joint pain scores post-programme. In addition, although the five-level EuroQoL questionnaire (EQ-5D-5L) is now the preferred measure for cost-effectiveness analyses across Europe, baseline scores were high (0.93), suggesting a ceiling effect for QALYs.

CONCLUSION

Participation in EuroFIT led to improvements in physical activity, diet, body weight, and biomarkers of cardiometabolic health, but not in sedentary time at 12 months. Within-trial analysis suggests it is not cost-effective in the short term for QALYs due to a ceiling effect in quality of life. Nevertheless, decision-makers may consider the incremental cost for increase in steps worth the investment.

TRIAL REGISTRATION

International Standard Randomised Controlled Trials, ISRCTN-81935608.

Cardiometabolic Impact of Changing Sitting, Standing, and Stepping in the Workplace

BACKGROUND

According to cross-sectional and acute experimental evidence, reducing sitting time should improve cardiometabolic health risk biomarkers. Furthermore, the improvements obtained may depend on whether sitting is replaced with standing or ambulatory activities. Based on data from the Stand Up Victoria multicomponent workplace intervention, we examined this issue using compositional data analysis-a method that can examine and compare all activity changes simultaneously.

METHODS

Participants receiving the intervention (n = 136 ≥ 0.6 full-time equivalent desk-based workers, 65% women, mean ± SD age = 44.6 ± 9.1 yr from seven worksites) were asked to improve whole-of-day activity by standing up, sitting less, and moving more. Their changes in the composition of daily waking hours (activPAL-assessed sitting, standing, and stepping) were quantified then tested for associations with concurrent changes in cardiometabolic risk (CMR) scores and 14 biomarkers concerning body composition, glucose, insulin, and lipid metabolism. Analyses were by mixed models, accounting for clustering (3 months, n = 105-120; 12 months, n = 80-97).

RESULTS

Sitting reduction was significantly (P < 0.05) associated only with lower systolic blood pressure at 3 months, and with CMR scores, weight, body fat, waist circumference, diastolic blood pressure, and fasting triglycerides, total/HDL cholesterol, and insulin at 12 months. Significant differences between standing and stepping were only observed for systolic blood pressure and insulin; both favored stepping. However, replacing sitting with standing was significantly associated only with improvements in CMR scores, whereas replacing sitting with stepping was significantly associated with CMR scores and six biomarkers.

CONCLUSIONS

Improvements in several cardiometabolic health risk biomarkers were significantly associated with sitting reductions that occurred in a workplace intervention. The greatest degree and/or widest range of cardiometabolic benefits appeared to occur with long-term changes, and when increasing ambulatory activities.

TRIAL REGISTRATION

ACTRN1211000742976.

Validation of a Novel Device to Measure and Provide Feedback on Sedentary Behavior

Purpose

Pedometers, which enable self-monitoring of step counts, are effective in facilitating increases in physical activity. Similar devices which provide real-time feedback on sedentary (sitting) behavior are limited. This study aimed to develop and validate a novel device—the SitFIT—which could accurately measure and provide feedback on sedentary behavior and physical activity.

Methods

The SitFIT is a triaxial accelerometer, developed by PAL Technologies, which is worn in the front trouser pocket. This enables tracking of thigh inclination and therefore differentiation between sitting and upright postures, as well as tracking of step count. It has a display to provide user feedback. To determine the validity of the SitFIT for measuring sedentary behavior and step counts, 21 men, age 30 to 65 yr, with body mass index 26.6 ± 3.9 kg·m⁻² wore a SitFIT in a front trouser pocket and an activPAL accelerometer attached to their thigh for up to 7 d. Outputs from the SitFIT were compared with the activPAL, which was assumed to provide criterion standard measurements of sitting and step counts.

Results

Mean step counts were approximately 4% lower with the SitFIT than activPAL, with correlation between the two methods being very high (r = 0.98) and no obvious bias from the line of equality (regression line, y = 1.0035x + 418.35). Mean sedentary time was approximately 5% higher with the SitFIT than activPAL, correlation between methods was high (r = 0.84), and the equation of the regression line was close to the line of equality (y = 0.8728x + 38.445).

Conclusions

The SitFIT has excellent validity for measurement of free-living step counts and sedentary time and therefore addresses a clear need for a device that can be used as a tool to provide feedback on sedentary behavior to facilitate behavior change.

Web-based physiotherapy for people affected by multiple sclerosis: a single blind, randomized controlled feasibility study

Objective:

To examine the feasibility of a trial to evaluate web-based physiotherapy compared to a standard home exercise programme in people with multiple sclerosis.

Design:

Multi-centre, randomized controlled, feasibility study.

Setting:

Three multiple sclerosis out-patient centres.

Participants:

A total of 90 people with multiple sclerosis (Expanded Disability Status Scale 4–6.5).

Interventions:

Participants were randomized to a six-month individualized, home exercise programme delivered via web-based physiotherapy ( n = 45; intervention) or a sheet of exercises ( n = 45; active comparator).

Outcome measures:

Outcome measures (0, three, six and nine months) included adherence, two-minute walk test, 25 foot walk, Berg Balance Scale, physical activity and healthcare resource use. Interviews were undertaken with 24 participants and 3 physiotherapists.

Results:

Almost 25% of people approached agreed to take part. No intervention-related adverse events were recorded. Adherence was 40%–63% and 53%–71% in the intervention and comparator groups. There was no difference in the two-minute walk test between groups at baseline (Intervention-80.4(33.91)m, Comparator-70.6(31.20)m) and no change over time (at six-month Intervention-81.6(32.75)m, Comparator-74.8(36.16)m. There were no significant changes over time in other outcome measures except the EuroQol-5 Dimension at six months which decreased in the active comparator group. For a difference of 8(17.4)m in two-minute walk test between groups, 76 participants/group would be required (80% power, P > 0.05) for a future randomized controlled trial.

Conclusion:

No changes were found in the majority of outcome measures over time. This study was acceptable and feasible by participants and physiotherapists. An adequately powered study needs 160 participants.

The associations of sedentary time and breaks in sedentary time with 24-hour glycaemic control in type 2 diabetes

The aim of this study was to investigate the associations of accelerometer-assessed sedentary time and breaks in sedentary time with 24-h events and duration of hypoglycaemia (<3.9 mmol/l), euglycaemia (3.9-7.8 mmol/l), hyperglycaemia (>7.8 mmol/l) and above target glucose (>9 mmol/l). Thirty-seven participants with type 2 diabetes (age, 62.8 ± 10.5 years; body mass index, 29.6 ± 6.8 kg/m2) in Glasgow, United Kingdom were enrolled between February 2016 and February 2017. Participants wore an activity monitor (activPAL3) recording the time and pattern of sedentary behaviour and a continuous glucose monitoring (CGM, Abbott FreeStyle Libre) for up to 14 days. Linear regression analyses were used to investigate the associations. Participants spent 3.7%, 64.7%, 32.1% and 19.2% of recording h/day in hypoglycaemia, euglycaemia, hyperglycaemia and above target, respectively. There was a negative association between sedentary time and time in euglycaemia (β = -0.44, 95% CI -0.86; -0.03, p = 0.04). There was a trend towards a positive association between sedentary time and time in hyperglycaemia (β = 0.36, 95% CI -0.05; 0.78, p = 0.08). Breaks in sedentary time was associated with higher time in euglycaemia (β = 0.38, 95% CI 0.00; 0.75, p = 0.04). To conclude, in individuals with type 2 diabetes, more time spent in unbroken and continuous sedentary behaviour was associated with poorer glucose control. Conversely, interrupting sedentary time with frequent breaks appears to improve glycaemic control. Therefore, this should be considered as a simple adjunct therapy to improve clinical outcomes in type 2 diabetes.

The Norwegian Cognitive impairment after stroke study (Nor-COAST): study protocol of a multicentre, prospective cohort study

BACKGROUND

Early and late onset post-stroke cognitive impairment (PCI) contributes substantially to disability following stroke, and is a high priority within stroke research. The aetiology for PCI is complex and related to the stroke itself, brain resilience, comorbid brain diseases, prestroke vulnerability and complications during the hospital stay. The aim of the Norwegian Cognitive Impairment After Stroke study (Nor-COAST) is to quantify and measure levels of cognitive impairments in a general Norwegian stroke population and to identify biological and clinical markers associated with prognosis for cognitive disorders following incident stroke. The study will be organised within five work packages: 1) Incidence and trajectories 2) Pathological mechanisms 3) Development of a risk score 4) Impact of physical activity and 5) Adherence to secondary prevention.

METHODS

Nor-COAST is an ongoing multicentre (five participating hospitals), prospective, cohort study with consecutive inclusion during the acute phase and with follow-up at three and 18 months, and at three years. Inclusion criteria are stroke defined according to the WHO criteria. During the recruitment period from 18.05.2015 to 31.03.2017, 816 participants have been included. Cognitive impairment will be classified according to the DSM-5 criteria using a consensus group. Cognitive function is assessed by a standardised neuropsychological test battery, the Montreal Cognitive Assessment, Trail making A and B, ten-word immediate and delayed recall test, the Controlled Oral Word Association, Global Deterioration Scale and proxy based information by and the Ascertain Dementia 8 item informant questionnaire. Biomarkers include magnetic resonance imaging, routine blood samples and bio-banking. Clinical assessments include characteristics of the stroke, comorbidity, delirium, frailty and tests for cognitive and physical function, sensor based activity monitoring and adherence to secondary prophylaxis.

DISCUSSION

Nor-COAST is the first Norwegian multicentre study to quantify burden of PCI that will provide reliable estimates in a general stroke population. A multidisciplinary approach aiming to identify biomarkers and clinical markers of overall prognosis will add new knowledge about risk profiles, including pre-stroke vulnerability and modifiable factors such as physical activity and secondary prophylaxis of relevance for clinical practice and later intervention studies.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02650531 . Retrospectively registered January 8, 2016. First participant included May 18, 2015.

Measuring Sedentary Behavior by Means of Muscular Activity and Accelerometry

Sedentary Behavior (SB) is among the most frequent human behaviors and is associated with a plethora of serious chronic lifestyle diseases as well as premature death. Office workers in particular are at an increased risk due to their extensive amounts of occupational SB. However, we still lack an objective method to measure SB consistent with its definition. We have therefore developed a new measurement system based on muscular activity and accelerometry. The primary aim of the present study was to calibrate the new-developed 8-CH-EMG+ for measuring occupational SB against an indirect calorimeter during typical desk-based office work activities. In total, 25 volunteers performed nine office tasks at three typical workplaces. Minute-by-minute posture and activity classification was performed using subsequent decision trees developed with artificial intelligence data processing techniques. The 8-CH-EMG+ successfully identified all sitting episodes (AUC = 1.0). Furthermore, depending on the number of electromyography channels included, the device has a sensitivity of 83–98% and 74–98% to detect SB and active sitting (AUC = 0.85–0.91). The 8-CH-EMG+ advances the field of objective SB measurements by combining accelerometry with muscular activity. Future field studies should consider the use of EMG sensors to record SB in line with its definition.

Breaking up Sedentary Time in Overweight/Obese Adults on Work Days and Non-Work Days: Results from a Feasibility Study

Office workers are vulnerable to the adverse health effects of sedentary behavior (i.e., sitting time). Increasing physical activity and preventing time spent sitting is an occupational health priority. This randomized crossover design study compared the short-term (3-days) effects of hourly interruptions of sedentary time with 5-min micrrobouts of activity for 9 hours (MICRO) to a sedentary control condition (SED) and a duration-matched continuous single bout of physical activity (45-min/d, ONE) condition on inclinometer-derived sitting-time on work and non-work days in sedentary overweight/obese adults. Differences in sitting/lying, standing, stepping, number of sit/stand transitions, time spent in moderate and vigorous activity (MVPA), energy expenditure, self-perceived vigor and fatigue, and insulin sensitivity were also examined. Twenty-two participants (10M/12F; 31.7 ± 1.3 year old BMI 30.4 ± 0.5 kg/m²) completed all conditions. No between-condition effects were observed in sitting-time and sit/stand transitions. Both interventions increased daily steps, MVPA and energy expenditure with increases being greater in ONE than MICRO. Feelings of vigor and fasting insulin sensitivity were also improved. Participants reported less fatigue with MICRO than SED and ONE. Both interventions increase physical activity and energy expenditure in occupational and leisure-time contexts. The sustainability of these effects over the long term and on health outcomes will need to be tested in future studies.

Comparison of a group-delivered and individually delivered lifestyle-integrated functional exercise (LiFE) program in older persons: a randomized noninferiority trial

BACKGROUND

The Lifestyle-Integrated Functional Exercise (LiFE) program is effective in improving strength, balance, and physical activity (PA) while simultaneously reducing falls in older people by incorporating exercise activities in recurring daily tasks. However, implementing the original LiFE program includes substantial resource requirements. Therefore, as part of the LiFE-is-LiFE project, a group format (gLiFE) of the LiFE program has been developed, which will be tested regarding its noninferiority to the individually delivered LiFE in terms of PA-adjusted fall incidence and overall cost-effectiveness.

METHODS

In a multi-centre, single-blinded noninferiority trial, an envisaged sample of N = 300 participants (> 70 years; faller and/or confirmed falls risk; community-dwelling) will be randomized in either LiFE or gLiFE. Both groups will undergo the same strength and balance activities as well as PA promotion activities and habitualization strategies as described in the LiFE programme, however, based on different approaches of delivery: During the 6-month intervention phase, LiFE participants will receive seven home visits and two telephone calls; in gLiFE, the program will be delivered in seven group sessions and also two telephone calls. Main outcomes are a) fall incidence per PA and b) incremental cost-effectiveness ratio comparing costs and quality-adjusted life years between the two interventions. Secondary outcomes include PA behaviour, motor performance, health status, psychosocial status, program evaluation, and adherence. Measurements will be conducted at baseline, 6-month and 12-month follow-up; evaluation of intervention sessions and assessment of psychosocial variables related to execution and habitualization of LiFE activities will be made during the intervention period as well.

DISCUSSION

Compared to LiFE, we expect gLiFE to (a) reduce falls per PA by a similar rate; (b) be more cost-effective; (c) comparably enhance physical performance in terms of strength and balance as well as PA. By investigating the economic and societal benefit, this study will be of high practical relevance as noninferiority of gLiFE would facilitate large-scale implementation due to lower resource usage. This would result in better reach and increased accessibility, which is important for subjects with a history of falls and/or being at risk of falls.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03462654 . Registered on March 12, 2018.