Association between questionnaire- and accelerometer-assessed physical activity: the role of sociodemographic factors

The association between accelerometer-assessed physical activity and respiratory function in older adults differs between smokers and non-smokers

The association between physical activity and lung function is thought to depend on smoking history but most previous research uses self-reported measures of physical activity. This cross-sectional study investigates whether the association between accelerometer-derived physical activity and lung function in older adults differs by smoking history. The sample comprised 3063 participants (age = 60–83 years) who wore an accelerometer during 9 days and undertook respiratory function tests. Forced vital capacity (FVC) was associated with moderate-to-vigorous physical activity (MVPA; acceleration ≥0.1 g (gravity)) in smokers but not in never smokers: FVC differences for 10 min increase in MVPA were 58.6 (95% Confidence interval: 21.1, 96.1), 27.8 (4.9, 50.7), 16.6 (7.9, 25.4), 2.8 (−5.2, 10.7) ml in current, recent ex-, long-term ex-, and never-smokers, respectively. A similar trend was observed for forced expiratory volume in 1 second. Functional data analysis, a threshold-free approach using the entire accelerometry distribution, showed an association between physical activity and lung function in all smoking groups, with stronger association in current and recent ex-smokers than in long-term ex- and never-smokers; the associations were evident in never smokers only at activity levels above the conventional 0.1 g MVPA threshold. These findings suggest that the association between lung function and physical activity in older adults is more pronounced in smokers than non-smokers.

Is vigorous-intensity physical activity required for improving bone mass in adolescence? Findings from a Brazilian birth cohort

The association between moderate and vigorous physical activity throughout adolescence and areal bone density (aBMD) at 18 years of age was evaluated. Vigorous-intensity physical activity at 11, 15, and 18 years was associated with aBMD in early adulthood, especially in boys. Cross-sectional analyses showed a positive association between moderate physical activity and aBMD.

INTRODUCTION

To evaluate independent associations of moderate and vigorous physical activity (MPA, VPA) across adolescence with areal bone mineral density (aBMD).

METHODS

Physical activity (PA) was assessed at 11, 15, and 18 years of age by self-report and at 18 years by accelerometry in the 1993 Pelotas Birth Cohort Study. Time spent in MPA and VPA was determined using metabolic equivalents and specific cutoffs based on raw acceleration. Lumbar spine and femoral neck aBMD were measured by DXA at 18 years. Statistical analyses evaluated the association of MPA and VPA with aBMD, after adjusting for skin color, asset index, current height and age at menarche, and peak strain score (based on ground reaction forces of PA).

RESULTS

Lumbar spine and femoral neck aBMD were available for 3947 (49.9% of boys) and 3960 (49.6% of boys) individuals, respectively. Time spent in MPA at 11 and 15 years was not associated with aBMD. VPA at all time points was positively related to both lumbar spine and femoral neck aBMD in boys. Results were consistent for objectively measured VPA. Girls who achieved 75+ minutes/week of VPA in at least two follow-ups showed higher aBMD at 18 years of age. Boys who reached 75+ minutes/week of VPA at all follow-ups had on average 0.117 g/cm² (95% CI: 0.090; 0.144) higher femoral neck aBMD than those who never achieved this threshold.

CONCLUSIONS

Self-reported VPA but not MPA throughout adolescence was associated with aBMD. Recommendation for PA in young people should consider the importance of VPA.

Integrating physical activity into the primary school curriculum: rationale and study protocol for the "Thinking while Moving in English" cluster randomized controlled trial

BACKGROUND

The current and declining physical activity levels of children is a global concern. Integrating physical activity into the school curriculum may be an effective way not only to improve children's physical activity levels but also enhance educational outcomes. Given the recent national focus in Australia on improving the literacy levels of children in primary school, and an increasing proportion of time spent on explicitly teaching these skills, integrating physical activity into English could be a viable strategy to improve literacy levels and physical activity at the same time. The aim of this study is to evaluate the impact of the 'Thinking While Moving in English' (TWM-E) program on children's physical activity, on-task behavior in the classroom, academic achievement, and executive function.

METHODS

Grade 3-4 children from 10 public schools in New South Wales, Australia will be randomly allocated to intervention (n = 5) or control (n = 5) groups. All teachers will receive 1-day workshop of registered professional learning and a TWM-E equipment pack (e.g., chalk, lettered bean bags). Intervention schools will be asked to adapt their English lessons to embed movement-based learning in their daily program for three 40-min lessons per week, over a six-week period. The primary outcome is children's physical activity levels across the school day (measured using accelerometry). Secondary outcomes are children's on-task behavior during English lessons, academic achievement in English, and executive function. A detailed process evaluation will be undertaken including questionnaires, fidelity checks, and teacher and student interviews.

DISCUSSION

The TWM-E program has the potential to improve primary school children's physical activity levels, along with academic outcomes (on-task behavior, cognition, and academic achievement), and provide stakeholders with exemplar lessons and guidelines which illustrate how to teach English to children whilst they are moving.

TRIAL REGISTRATION

Australian and New Zealand Clinical trial Register ACTRN12618001009202 Date registered: 15/06/2018 retrospectively registered.

Results from a natural experiment: initial neighbourhood investments do not change objectively-assessed physical activity, psychological distress or perceptions of the neighbourhood

BACKGROUND

Few studies have assessed objectively measured physical activity (PA), active transportation, psychological distress and neighborhood perceptions among residents of a neighborhood before and after substantial improvements in its physical environment. Also, most research-to-date has employed study designs subject to neighborhood selection, which may introduce bias in reported findings. We built upon a previously enrolled cohort of households from two low-income predominantly African American Pittsburgh neighborhoods, matched on socio-demographic composition including race/ethnicity, income and education. One of the two neighborhoods received substantial neighborhood investments over the course of this study including, but not limited to public housing development and greenspace/landscaping. We implemented a natural experiment using matched intervention and control neighborhoods and conducted pre-post assessments among the cohort. Our comprehensive assessments included accelerometry-based PA, active transportation, psychological distress and perceptions of the neighborhood, with assessments conducted both prior to and following the neighborhood changes. In 2013, we collected data from 1003 neighborhood participants and in 2016, we re-interviewed 676 of those participants. We conducted an intent to treat analysis, with a difference-in-difference estimator using attrition weighting to account for nonresponse between 2013 and 2016. In addition, we derived an individual-level indicator of exposure to neighbourhood investment and estimated effect of exposure to investment on the same set of outcomes using covariate-adjusted models.

RESULTS

We observed no statistically significant differences in activity, psychological distress, satisfaction with one's neighborhood as a place to live or any of the other measures we observed prior to and after the neighborhood investments between the intervention and control neighborhoods or those exposed vs not exposed to investments.

CONCLUSIONS

Using this rigorous study design, we observed no significant changes in the intervention neighborhood above and beyond secular trends present in the control neighborhood. Although neighborhood investment may have other benefits, we failed to see improvement in PA, psychological distress or related outcomes in the low-income African American neighborhoods in our study. This may be an indication that improvements in the physical environment may not directly translate into improvements in residents' physical activity or health outcomes without additional individual-level interventions. It is also possible that these investments were not dramatic enough to spur change within the three year period. Additional studies employing similar design with other cohorts in other settings are needed to confirm these results.

TRIAL REGISTRATION

Trial Registration is not applicable since we did not prospectively assign individuals to a health-related intervention.

Technically measured compositional physical work demands and prospective register-based sickness absence (PODESA): a study protocol

Background

Various physical work demands are shown to be associated with sickness absence. However, these studies have: (a) predominantly used self-reported data on physical work demands that have been shown to be inaccurate compared with technical measurements, (b) principally focused on various physical work demands in ‘isolation’, i.e. ignoring their co-dependency – compositional nature –, and (c) mainly used register data on long-term sickness absence. The present article describes the protocol of a study with the objective of investigating the association between technically measured compositional data on physical work demands and prospective long- and short-term register-based data on sickness absence.

Methods

‘The technically measured compositional Physical wOrk DEmands and prospective association with register-based Sickness Absence study (PODESA)’ comprises data from two Danish cohorts (NOMAD and DPhacto) primarily on blue-collar workers. In the PODESA cohort, data on 1108 workers were collected at baseline (between 2011 and 2014). The cohort data comprise, e.g., self-reported information on descriptives, lifestyle, workday, and health, as well as accelerometer-based measurements of physical work demands (physical activity, movements, and postures). These baseline measurements are linked with prospective register-based data on sickness absence for up to four years after baseline. The prospective association between physical work demands and sickness absence will be analysed using a Compositional Data Analysis approach.

Discussion

PODESA provides a unique possibility of unravelling which combinations of physical work demands are associated with prospective sickness absence. PODESA employs technically measured information on physical work demands (taking into account the compositionality of physical work demand data) and prospective sickness absence data. The findings from PODESA can be used to develop strengthened preventive interventions for sickness absence. Results are expected in 2019–2021.

The feasibility of online video calling to engage patients with cystic fibrosis in exercise training

Introduction

Physical activity, including structured exercise, is an essential component in the management of cystic fibrosis. The use of telehealth such as video-calling may be a useful method for the delivery of exercise and physical activity interventions, though the feasibility of this remains unknown.

Methods

Nine patients with cystic fibrosis (three female, six male, 30.9 ± 8.7 years) volunteered to participate. Participants completed an eight-week exercise training intervention conducted via Skype, using personalised exercises, with all sessions supervised by an exercise therapist. Feasibility was assessed by demand, implementation, practicality and acceptability. Changes in anthropometric, pulmonary, physical activity and quality of life variables were also assessed.

Results

Two male participants withdrew from the study, citing lack of available time. The remaining participants found use of Skype useful, with a mean satisfaction rating of 9/10, and three participants requesting to continue the sessions beyond the duration of the study. Mean compliance with sessions was 68%, with mean duration of sessions being 20 min. A total of 25% of calls suffered from technical issues such as video or audio lags. Anthropometric, pulmonary, physical activity and quality of life variables remained unchanged over the course of the study period.

Discussion

The use of Skype to deliver an exercise intervention to patients withcystic fibrosis was found to be technologically feasible, and acceptable among participants. Findings have implications for clinical practice and could allow care teams to engage patients remotely in exercise. Further research is required to assess the efficacy of this modality on increasing physical activity and associated health outcomes.

Step Counts of Middle-Aged and Elderly Adults for 10 Months Before and After the Release of Pokémon GO in Yokohama, Japan

Background

Smartphones have been integrated into our society and are expected to serve as tools to improve health outcomes. In the summer of 2016, Pokémon GO, a location-based augmented reality game for smartphones was released; it attracted attention from the perspective of health, especially with its potential to increase physical activity (PA). A few studies have compared objectively measured step counts before and after the release of the game; however, they were conducted over a short study period and evaluated only young people.

Objective

The objective of this study was to confirm whether there was a difference in step counts between middle-aged and elderly players and nonplayers before and after the release of Pokémon GO.

Methods

A total of 46 players and 184 nonplayers aged ≥40 years were matched for sex, age group, and PA level; they were respondents to a questionnaire randomly sent to citizens who were given free pedometers by Yokohama city. Their play status was identified through the questionnaire. To investigate the change in step counts before and after the release of Pokémon GO according to play status, a 2-way repeated-measures analysis of variance was performed. Step counts 1 month before the release of the game were compared with those 8 months after the release. In addition, subgroup analyses according to sex, age group, PA level, and subjective health status were performed.

Results

The mean ages of players and nonplayers were 56.5 (SD 9.9) years and 57.3 (SD 9.6) years, respectively, and the mean baseline step counts of players and nonplayers were 7641.8 (SD 2754.5) and 7903.3 (SD 2674.7), respectively. There was no significant difference in the age and baseline step counts according to a t test (2-tailed). In the analysis of all samples, the interaction between play status and time effect was significant for 3 of 8 months after release. In the subgroup analyses, the interaction was significant for 3 months in men, 7 months in the 55-64-year-old group, 2 months in workers, 4 months in the active group in PA level, and 2 months in participants with subjectively good health. The interaction was significant for only 1 month, at most, in other subgroups.

Conclusions

The present study confirmed a difference in step counts between players and nonplayers before and after the release of Pokémon GO. According to our analysis, step counts were higher until 7 months after the release. The player group maintained their step counts in winter, despite the decrease in step counts of nonplayers. In subgroup analyses, players were more likely to be men, aged <55 years, workers, active, and subjectively in good health.

Compliance with wrist-worn accelerometers in primiparous early postpartum women

Background

There are few studies that objectively assess physical activity using accelerometry in postpartum women and none that do so before 3 months postpartum. It is not known whether accelerometry can be successfully used in the early postpartum period and thus benefit studies designed to assess the health benefits and risks of early physical activity. Wear compliance may be substantially lower several weeks after childbirth, given the overwhelming nature of the early postpartum period, particularly for first time mothers. The aims of this study were to 1) describe the methods used to facilitate protocol compliance of wrist-worn accelerometry, 2) describe device usage and wear time in early postpartum primiparous women and 3) to place the compliance characteristics of early postpartum primiparous women in our study in context with that of other studies of postpartum women and standards published by large, physical activity surveillance studies.

Methods

Participants were primiparous women who were enrolled at 3^rd trimester in a larger ongoing prospective cohort study, delivered vaginally, and lived in a 60 mile radius of the research site. The parent study was designed to evaluate the effects of early physical activity on pelvic floor health. Participants wore a wrist accelerometer (ActiGraph™ GT3XLink device) over two 7-day periods, 2-3 weeks and 5-6 weeks postpartum. We developed a protocol based on best practices to enhance compliance in this population. The Choi (2011) algorithm was used to determine wear time.

Results

Of all participants, 82.6% (166 of 201 eligible) and 70.1% (141 of 201 eligible) at 2-3 and 5-6 weeks, respectively, received and wore a functional device in the correct study time-frame for at least 7 days. Of participants that received a functional device, 94.3% (166/176) and 86.5% (141/163) wore the device for at least 7 days, with mean wear times of 1348.0 (135.8) minutes/day and 1313.5 (152) minutes/day, respectively. At 2-3 weeks, 96.1% and 90.4% met the NHANES and Whitehall II Study wear standards, respectively, while at 5-6 weeks, 93.9% and 84.1% did so.

Conclusion

Despite challenges in conducting physical activity research in postpartum women, adherence to wrist-worn accelerometry is high with this protocol.

Genome-wide association analyses of chronotype in 697,828 individuals provides insights into circadian rhythms

Being a morning person is a behavioural indicator of a person’s underlying circadian rhythm. Using genome-wide data from 697,828 UK Biobank and 23andMe participants we increase the number of genetic loci associated with being a morning person from 24 to 351. Using data from 85,760 individuals with activity-monitor derived measures of sleep timing we find that the chronotype loci associate with sleep timing: the mean sleep timing of the 5% of individuals carrying the most morningness alleles is 25 min earlier than the 5% carrying the fewest. The loci are enriched for genes involved in circadian regulation, cAMP, glutamate and insulin signalling pathways, and those expressed in the retina, hindbrain, hypothalamus, and pituitary. Using Mendelian Randomisation, we show that being a morning person is causally associated with better mental health but does not affect BMI or risk of Type 2 diabetes. This study offers insights into circadian biology and its links to disease in humans.

GWAS have previously found 24 genomic loci associated with chronotype, an individual’s preference for early or late sleep timing. Here, the authors identify 327 additional loci in a sample of 697,828 individuals and further explore the relationships of chronotype with metabolic and psychiatric diseases.

The feasibility and acceptability of morning versus evening exercise for overweight and obese adults: A randomized controlled trial

Background

The time of day that people exercise could have an influence on the efficacy of exercise for weight loss, via differences in adherence and/or physiological adaptations. However, there is currently no evidence to support an optimal time of day for exercise to maximise efficacy.

Purpose

To examine the feasibility and acceptability of prescribed morning and evening exercise.

Methods

Twenty inactive, overweight adults aged 18–60 years were recruited for a 12-week intervention and randomized to one of three groups using a 2:2:1 random allocation ratio: i) morning exercise (AM; n = 9); ii) evening exercise (PM; n = 7); or iii) waitlist control (CON; n = 4). Exercise groups were prescribed self-paced walking or running on a treadmill to achieve a weekly total of 250 min. Feasibility and acceptability data were collected, and physiological and behavioural outcomes associated with energy balance were measured at baseline, mid- and post-intervention.

Results

Attrition was low (n = 2 dropped out), with high measurement completion rates (>80%). The intervention groups had high adherence rates to exercise sessions (94% and 87% for the AM and PM groups, respectively). No adverse events resulting from the intervention were reported. Both intervention groups displayed improvements to their cardiometabolic risk profile; cardiorespiratory fitness improved by 5.2 ± 4.7, and 4.6 ± 4.5 mL kg⁻¹.min⁻¹ and body fat percentage reduced by 1.2 ± 1.4, and −0.6 ± 1.2% for AM and PM groups, respectively.

Conclusion

This feasibility study provides evidence that morning and evening exercise interventions are feasible, and also provides justification for a large-scale randomized controlled trial.

Trial registration

This trial is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12616000457448p, 7/4/2016).

Shift-work nurses' work environments and health-promoting behaviours in relation to sleep disturbance: A cross-sectional secondary data analysis

AIMS AND OBJECTIVES

To examine the association of nursing work environments and health-promoting behaviours with shift-work nurses' sleep disturbance.

BACKGROUND

Shift-work nurses reportedly have sleep problems, which affect their sleep quality and quantity. Given the high risk of developing performance decrements and medication errors in sleep-disturbed nurses, factors related to sleep disturbance among shift-work nurses should be investigated.

DESIGN

A cross-sectional secondary data analysis.

METHODS

Our study analysed data from 339 nurses who had been involved in rotating shift work including night shifts for more than 6 months. To examine associations of nursing work environments and health-promoting behaviours with sleep disturbance, multiple linear regression models were generated. This study is reported in accordance with the STrengthening the Reporting of OBservational studies in Epidemiology guideline.

RESULTS

Nurses with more collegial relations with physicians were significantly less likely to have high levels of sleep disturbance (B = -4.01, p = 0.04). Those with higher levels of sleep disturbance were significantly more likely to report less stress management (B = -9.56, p < 0.01) and higher health responsibility (B = 9.30, p < 0.01).

CONCLUSIONS

To alleviate shift-work nurses' sleep disturbance, organisational supports for collaborative relations with physician and increased healthcare accessibility are needed. Individual nurses should develop healthy lifestyles to reduce occupational stress and alleviate sleep disorders.

RELEVANCE TO CLINICAL PRACTICE

To improve shift-work nurses' sleep, collegial relations with physicians and healthy lifestyles should be promoted.

Can the intensity of physical activity be accurately measured in older adults using questionnaires?

OBJECTIVES

This study assessed the accuracy of two questionnaires for measuring the duration of physical activity (PA) by intensity compared to an objective measure in older adults.

DESIGN

Cross-sectional observation METHODS: A total of 169 (female=43.8%) participants aged 73-78 years (mean: 75.1 y; SD: 1.3) wore a SenseWear™ Armband (SWA) for seven-days and reported the duration of PA by intensity with a Physical Activity Recall (PAR) questionnaire and the Active Australia Survey (AAS). In addition, the duration of moderate-to-vigorous-PA (MVPA) and overall active time, weighted for intensity (Total PA; MET: min/week) was assessed. Univariate general linear models were used to compare the questionnaire and SWA measures of PA while controlling for age, sex and education.

RESULTS

The PAR was associated with SWA moderate intensity PA (b=0.19; 95% CI 0.03-0.35), MVPA (b=0.19; 95% CI 0.02-0.37) and Total PA (b=0.33; 95% CI 0.11-0.55). Although significant correlations were present, the models explained a small proportion of the variance in the SWA variables. The AAS was not associated with the SWA for any PA outcome. There was also significant under-reporting of PA duration for both questionnaires in comparison to the SWA.

CONCLUSIONS

The PAR questionnaire may be suitable for determining the effect of greater levels of PA on health outcomes. However, neither questionnaire can be considered valid in determining the duration of PA divided by intensity. In addition, questionnaire and objectively measured PA are not equivalent and absolute measures of PA derived from questionnaires should be interpreted with caution.

Segmenting accelerometer data from daily life with unsupervised machine learning

Purpose

Accelerometers are increasingly used to obtain valuable descriptors of physical activity for health research. The cut-points approach to segment accelerometer data is widely used in physical activity research but requires resource expensive calibration studies and does not make it easy to explore the information that can be gained for a variety of raw data metrics. To address these limitations, we present a data-driven approach for segmenting and clustering the accelerometer data using unsupervised machine learning.

Methods

The data used came from five hundred fourteen-year-old participants from the Millennium cohort study who wore an accelerometer (GENEActiv) on their wrist on one weekday and one weekend day. A Hidden Semi-Markov Model (HSMM), configured to identify a maximum of ten behavioral states from five second averaged acceleration with and without addition of x, y, and z-angles, was used for segmenting and clustering of the data. A cut-points approach was used as comparison.

Results

Time spent in behavioral states with or without angle metrics constituted eight and five principal components to reach 95% explained variance, respectively; in comparison four components were identified with the cut-points approach. In the HSMM with acceleration and angle as input, the distributions for acceleration in the states showed similar groupings as the cut-points categories, while more variety was seen in the distribution of angles.

Conclusion

Our unsupervised classification approach learns a construct of human behavior based on the data it observes, without the need for resource expensive calibration studies, has the ability to combine multiple data metrics, and offers a higher dimensional description of physical behavior. States are interpretable from the distributions of observations and by their duration.

Rural-Urban Differences in Baseline Dietary Intake and Physical Activity Levels of Adolescents

INTRODUCTION

Differences in dietary intake and physical activity may explain the higher prevalence of obesity among adolescents living in rural versus urban settings. The objective of this cross-sectional secondary analysis was to compare baseline dietary intake and physical activity of adolescents by rurality.

METHODS

We analyzed data on 940 adolescents who participated in ACTION PAC (Adolescents Committed to Improvement of Nutrition and Physical Activity), an obesity prevention and management intervention trial conducted from 2014 through 2017 in 8 public high schools in the southwestern United States. Dietary intake was assessed with the Block Food Screener, and participants completed an exercise log and wore an accelerometer to provide data on physical activity. We compared data by rural-urban commuting area (RUCA) codes and log population density by using multilevel models, with students nested within zip code and repeated measures for accelerometer analysis.

RESULTS

After adjusting for socioeconomic status and ethnicity, accelerometer data indicated that moderate-to-vigorous physical activity was 8.17 min/d (P = .02) higher and sedentary time was 20.42 min/d (P = .02) lower in moderately urban areas than in the urban reference area. Each 1-unit increase in log population density was associated with higher reported intake of whole grains (0.02 ounce equivalents, P = .03), potatoes (0.01 cup equivalents, P = .02), and added sugar (0.37 tsp, P = .02) after adjusting for socioeconomic status and ethnicity.

CONCLUSION

Differences in reported dietary intake and physical activity level by measures of rurality were small and inconsistent in direction to explain the disparities observed in rural versus urban areas.

GWAS identifies 14 loci for device-measured physical activity and sleep duration

Physical activity and sleep duration are established risk factors for many diseases, but their aetiology is poorly understood, partly due to relying on self-reported evidence. Here we report a genome-wide association study (GWAS) of device-measured physical activity and sleep duration in 91,105 UK Biobank participants, finding 14 significant loci (7 novel). These loci account for 0.06% of activity and 0.39% of sleep duration variation. Genome-wide estimates of ~ 15% phenotypic variation indicate high polygenicity. Heritability is higher in women than men for overall activity (23 vs. 20%, p = 1.5 × 10-4) and sedentary behaviours (18 vs. 15%, p = 9.7 × 10-4). Heritability partitioning, enrichment and pathway analyses indicate the central nervous system plays a role in activity behaviours. Two-sample Mendelian randomisation suggests that increased activity might causally lower diastolic blood pressure (beta mmHg/SD: -0.91, SE = 0.18, p = 8.2 × 10-7), and odds of hypertension (Odds ratio/SD: 0.84, SE = 0.03, p = 4.9 × 10-8). Our results advocate the value of physical activity for reducing blood pressure.

The effect of socioeconomic deprivation on the association between an extended measurement of unhealthy lifestyle factors and health outcomes: a prospective analysis of the UK Biobank cohort

BACKGROUND

Combinations of lifestyle factors interact to increase mortality. Combinations of traditional factors such as smoking and alcohol are well described, but the additional effects of emerging factors such as television viewing time are not. The effect of socioeconomic deprivation on these extended lifestyle risks also remains unclear. We aimed to examine whether deprivation modifies the association between an extended score of lifestyle-related risk factors and health outcomes.

METHODS

Data for this prospective analysis were sourced from the UK Biobank, a prospective population-based cohort study. We assigned all participants an extended lifestyle score, with 1 point for each unhealthy lifestyle factor (incorporating sleep duration and high television viewing time, in addition to smoking, excessive alcohol, poor diet [low intake of oily fish or fruits and vegetables, and high intake of red meat or processed meats], and low physical activity), categorised as most healthy (score 0-2), moderately healthy (score 3-5), or least healthy (score 6-9). Cox proportional hazards models were used to examine the association between lifestyle score and health outcomes (all-cause mortality and cardiovascular disease mortality and incidence), and whether this association was modified by deprivation. All analyses were landmark analyses, in which participants were excluded if they had an event (death or cardiovascular disease event) within 2 years of recruitment. Participants with non-communicable diseases (except hypertension) and missing covariate data were excluded from analyses. Participants were also excluded if they reported implausible values for physical activity, sleep duration, and total screen time. All analyses were adjusted for age, sex, ethnicity, month of assessment, history of hypertension, systolic blood pressure, medication for hypercholesterolaemia or hypertension, and body-mass index categories.

FINDINGS

328 594 participants aged 40-69 years were included in the study, with a mean follow-up period of 4·9 years (SD 0·83) after the landmark period for all-cause and cardiovascular disease mortality, and 4·1 years (0·81) for cardiovascular disease incidence. In the least deprived quintile, the adjusted hazard ratio (HR) in the least healthy lifestyle category, compared with the most healthy category, was 1·65 (95% CI 1·25-2·19) for all-cause mortality, 1·93 (1·16-3·20) for cardiovascular disease mortality, and 1·29 (1·10-1·52) for cardiovascular disease incidence. Equivalent HRs in the most deprived quintile were 2·47 (95% CI 2·04-3·00), 3·36 (2·36-4·76), and 1·41 (1·25-1·60), respectively. The HR for trend for one increment change towards least healthy in the least deprived quintile compared with that in the most deprived quintile was 1·25 (95% CI 1·12-1·39) versus 1·55 (1·40-1·70) for all-cause mortality, 1·30 (1·05-1·61) versus 1·83 (1·54-2·18) for cardiovascular disease mortality, and 1·10 (1·04-1·17) versus 1·16 (1·09-1·23) for cardiovascular disease incidence. A significant interaction was found between lifestyle and deprivation for all-cause and cardiovascular disease mortality (both p_interaction<0·0001), but not for cardiovascular disease incidence (p_interaction=0·11).

INTERPRETATION

Wide combinations of lifestyle factors are associated with disproportionate harm in deprived populations. Social and fiscal policies that reduce poverty are needed alongside public health and individual-level interventions that address a wider range of lifestyle factors in areas of deprivation.

FUNDING

None.

Association between maximal oxygen consumption and physical activity and sedentary lifestyle in metabolic syndrome. Usefulness of questionnaires

INTRODUCTION AND OBJECTIVES

To analyze whether variations in physical activity (PA) and sedentary behaviors are accompanied by differences in maximal oxygen consumption (VO_2max).

METHODS

We conducted a prospective cross-sectional study of 243 participants (82 women), aged 65.0±4.9 years old, with metabolic syndrome and overweight/obesity who performed a maximal exercise test with expired gas analysis. PA was evaluated using subjective methods, the REGICOR and RAPA 1 self-reported questionnaires, and objective methods, the chair test and accelerometry. Sedentariness was analyzed with the Nurses' Health Study questionnaire and accelerometry.

RESULTS

VO_2max was higher in participants who reported they adhered to the recommendations of the PA guidelines in the REGICOR questionnaire (21.3±4.6 vs 18.0±4.4 mL/kg/min; P <.001) and was 18% higher in those who reported more PA in the RAPA 1 questionnaire than the less active group (P <.001). The chair test (> 15 vs ≤ 15 repetitions) also showed significant differences in VO_2max (21.2±4.8 vs 18.7±4.5 ml/kg/min; P <.001). Correlations between PA variables and VO_2max were significant but low (r: 0.2 to 0.4). Sedentary activities showed less relationship with VO_2max.

CONCLUSIONS

Participants with metabolic syndrome and overweight/obesity who reported adhering to PA recommendations achieved higher VO_2max. The self-reported questionnaires and the chair test identified significant variations in VO_2max. Sedentary activities do not appear to modify VO_2max.

Comparison of self-reported and accelerometer-assessed measurements of physical activity according to socio-demographic characteristics in Korean adults

OBJECTIVES

Previous studies have shown relatively low correlations between self-reported and accelerometer-assessed physical activity (PA). However, this association differs by socio-demographic factors, and this relationship has not been fully investigated in the general population. Thus, we investigated the correlation between self-reported and accelerometer-assessed PA and whether it differed by demographic and socioeconomic factors among the Korean general population.

METHODS

This cross-sectional study included 623 participants (203 men and 420 women) aged 30 to 64 years, who completed a PA questionnaire and wore a wrist-worn accelerometer on the non-dominant wrist for 7 days. We examined the agreement for metabolic equivalent task minutes per week (MET-min/wk) between the 2 measures and calculated Spearman correlation coefficients according to demographic and socioeconomic factors.

RESULTS

The kappa coefficient between tertiles of self-reported and accelerometer-assessed total MET-min/wk was 0.16 in the total population, suggesting overall poor agreement. The correlation coefficient between the 2 measurements was 0.26 (p<0.001) in the total population, and the correlation tended to decrease with increasing age (p for trend <0.001) and depression scores (p for trend <0.001).

CONCLUSIONS

We found a low correlation between self-reported and accelerometer-assessed PA among healthy Korean adults, and the correlation decreased with age and depression score. When studying PA using accelerometers and/or questionnaires, age and depression need to be considered, as should differences between self-reported and accelerometer-assessed PA.

Lower objectively measured physical activity is linked with perceived risk of hypoglycemia in type 1 diabetes

AIMS

Compare physical activity (PA) levels in adults with and without type 1 diabetes and identify diabetes-specific barriers to PA.

METHODS

Forty-four individuals with type 1 diabetes and 77 non-diabetic controls in the Coronary Artery Calcification in Type 1 Diabetes study wore an accelerometer for 2 weeks. Moderate-to-vigorous physical activity (MVPA) was compared by diabetes status using multiple linear regression. The Barriers to Physical Activity in Type 1 Diabetes questionnaire measured diabetes-specific barriers to PA, and the Clarke hypoglycemia awareness questionnaire measured hypoglycemia frequency.

RESULTS

Individuals with type 1 diabetes engaged in less MVPA, fewer bouts of MVPA, and spent less time in MVPA bouts per week than individuals without diabetes (all p < 0.05), despite no difference in self-reported PA (p > 0.05). The most common diabetes-specific barrier to PA was risk of hypoglycemia. Individuals with diabetes reporting barriers spent less time in MVPA bouts per week than those not reporting barriers (p = 0.047).

CONCLUSIONS

Individuals with type 1 diabetes engage in less MVPA than those without diabetes despite similar self-reported levels, with the main barrier being perceived risk of hypoglycemia. Adults with type 1 diabetes require guidance to meet current PA guidelines and reduce cardiovascular risk.

Examining the efficacy of a multicomponent m-Health physical activity, diet and sleep intervention for weight loss in overweight and obese adults: randomised controlled trial protocol

INTRODUCTION

Traditional behavioural weight loss trials targeting improvements in physical activity and diet are modestly effective. It has been suggested that sleep may have a role in weight loss and maintenance. Improving sleep health in combination with physical activity and dietary behaviours may be one strategy to enhance traditional behavioural weight loss trials. Yet the efficacy of a weight loss intervention concurrently targeting improvements in physical activity, dietary and sleep behaviours remains to be tested.

METHODS AND ANALYSIS

The primary aim of this three-arm randomised controlled trial is to examine the efficacy of a multicomponent m-Health behaviour change weight loss intervention relative to a waitlist control group. The secondary aims are to compare the relative efficacy of a physical activity, dietary behaviour and sleep intervention (enhanced intervention), compared with a physical activity and dietary behaviour only intervention (traditional intervention), on the primary outcome of weight loss and secondary outcomes of waist circumference, glycated haemoglobin, physical activity, diet quality and intake, sleep health, eating behaviours, depression, anxiety and stress and quality of life. Assessments will be conducted at baseline, 6 months (primary endpoint) and 12 months (follow-up). The multicomponent m-Health intervention will be delivered using a smartphone/tablet 'app', supplemented with email and SMS and individualised in-person dietary counselling. Participants will receive a Fitbit, body weight scales to facilitate self-monitoring, and use the app to access educational material, set goals, self-monitor and receive feedback about behaviours. Generalised linear models using an analysis of covariance (baseline adjusted) approach will be used to identify between-group differences in primary and secondary outcomes, following an intention-to-treat principle.

ETHICS AND DISSEMINATION

The Human Research Ethics Committee of The University of Newcastle Australia provided approval: H-2017-0039. Findings will be disseminated via publication in peer-reviewed journals, conference presentations, community presentations and student theses.

TRIAL REGISTRATION NUMBER

ACTRN12617000735358; UTN1111-1219-2050.

Associations of partnering transition and socioeconomic status with a four-year change in daily steps among Finnish adults

Aim: The aim of this prospective four-year follow-up study was to examine how socioeconomic status (SES) and change in marital status are associated with the change in pedometer-measured physical activity (PA) in adulthood among participants in the ‘Cardiovascular Risk in Young Finns Study’. Methods: Questionnaires were completed and pedometers worn at baseline in 2007 and again at follow-up in 2011 by 1051 Finnish adults (62.3% female, aged 30–45 years in 2007). A latent change score model was used to examine mean change in daily total steps, aerobic steps and non-aerobic steps during weekdays and weekend days between 2007 and 2011. Results: In women re-coupling or finding a new partner was associated with decrease in total steps ( p=0.010) and being single was associated with increase in non-aerobic steps ( p=0.047) during weekdays from 2007 to 2011 compared to women who were married. In men, divorcing was associated with decrease in non-aerobic steps ( p=0.049). Conclusions: In order to promote PA in the general population of adults, it is recommended to pay attention to people with lower SES and those who have had changes in their marital status. These factors could be taken into account when developing strategies to promote PA among the adult population.

Reconsidering the experience machine: Self-reported versus objective measures of physical activity to increase positive affect

This article tests the utility of self-report and objective assessment of physical activity to predict increased positive affect. Participants wore Fitbit activity trackers and responded to single-item assessments of momentary affect and self-reported physical activity following an experience sampling method protocol. A test of the within-person mediation indicated that, on average, 63 percent of the relationship between objective physical activity and affect was accounted for by self-reported physical activity. This research adds to the body of literature demonstrating the benefits of physical activity and discusses the utility of perceived over actual assessments of physical activity in naturalistic settings.

Associations of device-measured physical activity across adolescence with metabolic traits: Prospective cohort study

BACKGROUND

Multiple occasions of device-measured physical activity have not been previously examined in relation to metabolic traits. We described associations of total activity, moderate-to-vigorous physical activity (MVPA), and sedentary time from three accelerometry measures taken across adolescence with detailed traits related to systemic metabolism.

METHODS AND FINDINGS

There were 1,826 male and female participants recruited at birth in 1991-1992 via mothers into the Avon Longitudinal Study of Parents and Children offspring cohort who attended clinics in 2003-2005, 2005-2006, and 2006-2008 who were included in ≥1 analysis. Waist-worn uniaxial accelerometers measured total activity (counts/min), MVPA (min/d), and sedentary time (min/d) over ≥3 d at mean age 12y, 14y, and 15y. Current activity (at age 15y), mean activity across occasions, interaction by previous activity, and change in activity were examined in relation to systolic and diastolic blood pressure, insulin, C-reactive protein, and 230 traits from targeted metabolomics (nuclear magnetic resonance spectroscopy), including lipoprotein cholesterol and triglycerides, amino and fatty acids, glycoprotein acetyls, and others, at age 15y. Mean current total activity was 477.5 counts/min (SD = 164.0) while mean MVPA and sedentary time durations were 23.6 min/d (SD = 17.9) and 522.1 min/d (SD = 66.0), respectively. Mean body mass index at age 15y was 21.4 kg/m2 (SD = 3.5). Correlations between first and last activity measurement occasions were low (e.g., r = 0.40 for counts/min). Current activity was most strongly associated with cholesterol and triglycerides in high-density lipoprotein (HDL) and very low-density lipoprotein (VLDL) particles (e.g., -0.002 mmol/l or -0.18 SD units; 95% CI -0.24--0.11 for triglycerides in chylomicrons and extremely large very low-density lipoprotein [XL VLDL]) and with glycoprotein acetyls (-0.02 mmol/l or -0.16 SD units; 95% CI -0.22--0.10), among others. Associations were similar for mean activity across 3 occasions. Attenuations were modest with adjustment for fat mass index based on dual-energy X-ray absorptiometry (DXA). In mutually adjusted models, higher MVPA and sedentary time were oppositely associated with cholesterol and triglycerides in VLDL and HDL particles (MVPA more strongly with glycoprotein acetyls and sedentary time more strongly with amino acids). Associations appeared less consistent for sedentary time than for MVPA based on longer-term measures and were weak for change in all activity types from age 12y-15y. Evidence was also weak for interaction between activity types at age 15y and previous activity measures in relation to most traits (minimum P = 0.003; median P = 0.26 for counts/min) with interaction coefficients mostly positive. Study limitations include modest sample sizes and relatively short durations of accelerometry measurement on each occasion (3-7 d) and of time lengths between first and last accelerometry occasions (<4 years), which can obscure patterns from chance variation and limit description of activity trajectories. Activity was also recorded using uniaxial accelerometers which predated more sensitive triaxial devices.

CONCLUSIONS

Our results support associations of physical activity with metabolic traits that are small in magnitude and more robust for higher MVPA than lower sedentary time. Activity fluctuates over time, but associations of current activity with most metabolic traits do not differ by previous activity. This suggests that the metabolic effects of physical activity, if causal, depend on most recent engagement.

Associations Between Objectively Measured Physical Activity, Body Composition and Sarcopenia: Findings from the Hertfordshire Sarcopenia Study (HSS)

Regular physical activity (PA) is associated with reduced risk of the development and progression of musculoskeletal, metabolic and vascular disease. However, PA declines with age and this can contribute to multiple adverse outcomes. The aims of this study were to describe the relationship between accelerometer-determined PA, body composition and sarcopenia (the loss of muscle mass and function with age). Seven-day PA was measured using the GENEactiv accelerometer among 32 men and 99 women aged 74-84 years who participated in the Hertfordshire Sarcopenia Study. We measured mean daily acceleration and minutes/day spent in non-sedentary and moderate-to-vigorous physical activity (MVPA) levels. Body composition was measured by dual-energy X-ray absorptiometry, muscle strength by grip dynamometry and function by gait speed. Sarcopenia was defined according to the EWGSOP diagnostic algorithm. Men and women spent a median (inter-quartile range) of 138.8 (82, 217) and 186 (122, 240) minutes/day engaging in non-sedentary activity but only 14.3 (1.8, 30.2) and 9.5 (2.1, 18.6) min in MVPA, respectively. Higher levels of PA were associated with reduced adiposity, faster walking speed and decreased risk of sarcopenia. For example, a standard deviation (SD) increase in mean daily acceleration was associated with an increase in walking speed of 0.25 (95% CI 0.05, 0.45) SDs and a reduction in the risk of sarcopenia of 35% (95% CI 1, 57%) in fully adjusted analyses. PA was not associated with hand grip strength. Community-dwelling older adults in this study were largely sedentary but there was evidence that higher levels of activity were associated with reduced adiposity and improved function. PA at all intensity levels in later life may help maintain physical function and protect against sarcopenia.

Estimating sleep parameters using an accelerometer without sleep diary

Wrist worn raw-data accelerometers are used increasingly in large-scale population research. We examined whether sleep parameters can be estimated from these data in the absence of sleep diaries. Our heuristic algorithm uses the variance in estimated z-axis angle and makes basic assumptions about sleep interruptions. Detected sleep period time window (SPT-window) was compared against sleep diary in 3752 participants (range = 60-82 years) and polysomnography in sleep clinic patients (N = 28) and in healthy good sleepers (N = 22). The SPT-window derived from the algorithm was 10.9 and 2.9 minutes longer compared with sleep diary in men and women, respectively. Mean C-statistic to detect the SPT-window compared to polysomnography was 0.86 and 0.83 in clinic-based and healthy sleepers, respectively. We demonstrated the accuracy of our algorithm to detect the SPT-window. The value of this algorithm lies in studies such as UK Biobank where a sleep diary was not used.

A comparison of physical activity from Actigraph GT3X+ accelerometers worn on the dominant and non-dominant wrist

The purpose of this study was to evaluate the agreement between several activity measures using raw acceleration data from accelerometers worn concurrently on the dominant and non-dominant wrist. Fifty-five adults (31·9 ± 9·7 years, 26 males) wore two ActiGraph GT3X+ monitors continuously for 1 day, one on their non-dominant wrist and the other on their dominant wrist. Paired t-tests were undertaken with sequential Holm-Bonferroni corrections to compare wear time, moderate-vigorous physical activity (MVPA), time spent in 10-min bouts of MVPA (MVPA_10 min ) and the average magnitude of dynamic wrist acceleration (ENMO). Level of agreement between outcome variables from the wrists was examined using intraclass correlation coefficients (ICC, single measures, absolute agreement) with 95% confidence intervals and limits of agreement (LoA). Time spent across acceleration levels in 40 mg resolution were also examined. There were no significant differences between the non-dominant and dominant wrist for ENMO, wear time, MVPA or MVPA_10 min . Agreement between wrists was strong for most outcomes (ICC ≥0·92) including wear time, ENMO, MVPA, MVPA_10 min and the distribution of time across acceleration levels. Agreement was strong in the low acceleration bands (ICC = 0·970 and 0·922) with a mean bias of 3·08 min (LoA -55·18 to 61·34) and -5·43 (LoA -43·47 to 32·62). In summary, ENMO, MVPA, MVPA_10 min , wear time and the distribution of time across acceleration levels compared well at the group level. The LOA from the two lowest acceleration levels suggest further work over a longer monitoring period is needed to determine whether outputs from each wrist are comparable.

Web-Based Intervention Using Behavioral Activation and Physical Activity for Adults With Depression (The eMotion Study): Pilot Randomized Controlled Trial

Background

Physical activity is a potentially effective treatment for depression and depressive relapse. However, promoting physical activity in people with depression is challenging. Interventions informed by theory and evidence are therefore needed to support people with depression to become more physically active. eMotion is a Web-based intervention combining behavioral activation and physical activity promotion for people in the community with symptoms of depression.

Objective

The objectives were to assess the feasibility and acceptability of delivering eMotion to people in the community with symptoms of depression and to explore outcomes.

Methods

Participants with elevated depressive symptoms were recruited from the community through various methods (eg, social media) and randomized to eMotion or a waiting list control group for 8 weeks. eMotion is an administratively supported weekly modular program that helps people use key behavior change techniques (eg, graded tasks, action planning, and self-monitoring) to re-engage in routine, pleasurable, and necessary activities, with a focus on physical activities. Feasibility data were collected that included the following: recruitment and trial retention rates; fidelity of intervention delivery, receipt, and enactment; and acceptability of the intervention and data collection procedures. Data were collected for the primary (depression) and secondary outcomes (eg, anxiety, physical activity, fidelity, and client satisfaction) at baseline and 2 months postrandomization using self-reported Web-based questionnaires and accelerometers. Delivery fidelity (logins, modules accessed, time spent) was tracked using Web usage statistics. Exploratory analyses were conducted on the primary and secondary outcomes.

Results

Of the 183 people who contacted the research team, 62 were recruited and randomized. The mean baseline score was 14.6 (SD 3.2) on the 8-item Patient Health Questionnaire depression scale (PHQ-8). Of those randomized, 52 participants provided accelerometer-recorded physical activity data at baseline that showed a median of 35.8 (interquartile range [IQR] 0.0-98.6) minutes of moderate-to-vigorous physical activity (MVPA) recorded in at least 10-minute bouts per week, with only 13% (7/52) people achieving guideline levels (150 minutes of MVPA per week). In total, 81% (50/62) of participants provided follow-up data for the primary outcome (PHQ-8), but only 39% (24/62) provided follow-up accelerometer data. Within the intervention group, the median number of logins, modules accessed, and total minutes spent on eMotion was 3 (IQR 2.0-8.0), 3 (IQR 2.0-5.0), and 41.3 (IQR 18.9-90.4), respectively. Acceptability was mixed. Exploratory data analysis showed that PHQ-8 levels were lower for the intervention group than for the control group at 2 months postrandomization (adjusted mean difference −3.6, 95% CI −6.1 to −1.1).

Conclusions

It was feasible to deliver eMotion in UK communities to inactive populations. eMotion has the potential to be effective and is ready for testing in a full-scale trial. Further work is needed to improve engagement with both the intervention and data collection procedures.

Trial Registration

ClinicalTrials.gov NCT03084055; https://clinicaltrials.gov/ct2/show/NCT03084055 (Archived by WebCite at http://www.webcitation.org/6zoyM8UXa)

Intelligence in youth and health behaviours in middle age

OBJECTIVE

We investigated the association between intelligence in youth and a range of health-related behaviours in middle age.

METHOD

Participants were the 5347 men and women who responded to the National Longitudinal Survey of Youth 1979 (NLSY-79) 2012 survey. IQ was recorded with the Armed Forces Qualification Test (AFQT) when participants were aged 15 to 23 years of age. Self-reports on exercise (moderate activity, vigorous activity, and strength training), dietary, smoking, drinking, and oral health behaviours were recorded when participants were in middle age (mean age = 51.7 years). A series of regression analyses tested for an association between IQ in youth and the different health related behaviours in middle age, while adjusting for childhood socio-economic status (SES) and adult SES.

RESULTS

Higher IQ in youth was significantly associated with the following behaviours that are beneficial to health: being more likely to be able to do moderate cardiovascular activity (Odds Ratio, 95% CI) (1.72, 1.35 to 2.20, p < .001) and strength training (1.61, 1.37 to 1.90, p < .001); being less likely to have had a sugary drink in the previous week (0.75, 0.71 to 0.80, p < .001); a lower likelihood of drinking alcohol heavily (0.67, 0.61 to 0.74, p < .001); being less likely to smoke (0.60, 0.56 to 0.65, p < .001); being more likely to floss (1.47, 1.35 to 1.59, p < .001); and being more likely to say they "often" read the nutritional information (1.20, 1.09 to 1.31, p < .001) and ingredients (1.24, 1.12 to 1.36, p < .001) on food packaging compared to always reading them. Higher IQ was also linked with dietary behaviours that may or may not be linked with poorer health outcomes (i.e. being more likely to have skipped a meal (1.10, 1.03 to 1.17, p = .005) and snacked between meals (1.37, 1.26 to 1.50, p < .001) in the previous week). An inverted u-shaped association was also found between IQ and the number of meals skipped per week. Higher IQ was also linked with behaviours that are known to be linked with poorer health (i.e. a higher likelihood of drinking alcohol compared to being abstinent from drinking alcohol (1.58, 1.47 to 1.69, p < .001)). A u-shaped association was found between IQ and the amount of alcohol consumed per week and an inverted u-shaped association was found between IQ and the number of cigarettes smoked a day. Across all outcomes, adjusting for childhood SES tended to attenuate the estimated effect size only slightly. Adjusting for adult SES led to more marked attenuation but statistical significance was maintained in most cases.

CONCLUSION

In the present study, a higher IQ in adolescence was associated with a number of healthier behaviours in middle age. In contrast to these results, a few associations were also identified between higher intelligence and behaviours that may or may not be linked with poor health (i.e. skipping meals and snacking between meals) and with behaviours that are known to be linked with poor health (i.e. drinking alcohol and the number of cigarettes smoked). To explore mechanisms of association, future studies could test for a range of health behaviours as potential mediators between IQ and morbidity or mortality in later life.

Associations of object control motor skill proficiency, game play competence, physical activity and cardiorespiratory fitness among primary school children

This study investigated if object control relates to children's game play competence, and examined these competencies as correlates of physical activity and cardiorespiratory fitness. Game play (Game Performance Assessment Instrument), object control (The Test Gross Motor Development-3), moderate-to-vigorous physical activity (Accelerometry), and cardiorespiratory fitness (20-metre shuttle) assessments were completed for 107 children (57% Female, 43% Male) aged 9-12 years (M 10.53, SD 0.65). Two-level regression of object control on game play competence, and object control and game play competence on physical activity and cardiorespiratory fitness assessed associations. Object control competence was positively associated with game play competence (Std. B = 0.25, t (104.77) = 2.38, p = 0.001). Game play competence (Std. B = 0.33, t (99.81) = 5.21, p < 0.000) was more strongly associated with moderate-to-vigorous physical activity than object control competence (Std. B = 0.20, t (106.93) = 2.96, p = 0.003). Likewise, game competence (Std. B = 0.39, t (104.41) = 4.36, p < 0.000) was more strongly associated with cardiorespiratory fitness than object control competence (Std. B = 0.22, t (106.69) = 2.63, p = 0.002). Object control and game competence are both important as correlates of physical activity and cardiorespiratory fitness in children.

Objective Measures of Activity in the Elderly: Distribution and Associations With Demographic and Health Factors

BACKGROUND

Little is known about the distribution of activity over the full 24-hour spectrum in late old age and its association with demographic and health factors. Therefore, we aimed to evaluate the distribution of physical activity (PA), sedentary behavior, and sleep, and associated factors in the elderly population.

METHODS

Our study included 1210 participants (51.9% women) aged 70-94 years [mean age 77.5 years, standard deviation (SD) 5.0] from the population-based Rotterdam Study. Participants wore a triaxial accelerometer (GENEActiv) around the wrist for 7 days between July 2014 and June 2016. We examined if PA, sedentary behavior, and sleep differed by age, sex, body mass index (BMI), smoking status, alcohol consumption, education, season, functional capacity, marital status, presence of chronic disease, and use of sleep medication.

RESULTS

Mean total PA, expressed in milli-gravity (mg) units, was slightly higher for women (20.3, SD 5.6) than for men (19.3, SD 5.2, P < .01). Mean (SD) daily duration spent in sedentary behavior and light and moderate-to-vigorous PA was 13.3 (1.5) h/d, 147.5 (31.5) min/d, and 75.0 (25.5) min/d, respectively, among women; and 13.8 (1.6) h/d, 140.5 (31.1) min/d, and 71.5 (24.5) min/d, respectively, among men. Women spent on average 6.7 (SD 1.1) h/d sleeping and men 6.6 (1.4) h/d. Across increasing categories of age and BMI and in participants with chronic disease and disability, time spent in light and moderate-to-vigorous PA was decreased. Higher age and BMI were associated with more sedentary time. In addition, obese men spent slightly more time sleeping than their normal weight counterparts and women spent slightly less time sleeping in the summer than in spring.

CONCLUSIONS

PA and sedentary behavior in the elderly differed by sex, age, BMI, prevalence of chronic disease, and disability, whereas there were no clear patterns for sleep. On average, our participants spent up to 79.5% of their time awake being sedentary and 7%-8% in moderate-to-vigorous PA. Replacing sedentary behavior with light PA would be a good starting point for those with the lowest level of PA. Older adults, those with high BMI and worse health could benefit from targeted interventions to increase PA.

The power of social networks and social support in promotion of physical activity and body mass index among African American adults

Social support and social networks can elucidate important structural and functional aspects of social relationships that are associated with health-promoting behaviors, including Physical Activity (PA) and weight. A growing number of studies have investigated the relationship between social support, social networks, PA and obesity specifically among African Americans; however, the evidence is mixed and many studies focus exclusively on African American women. Most studies have also focused on either functional or structural aspects of social relationships (but not both) and few have objectively measured moderate-to-vigorous physical activity (MVPA) and body mass index (BMI). Cross-sectional surveys of adult African American men and women living in two low-income predominantly African American neighborhoods in Pittsburgh, PA (N = 799) measured numerous structural features as well as functional aspects of social relationships. Specifically, structural features included social isolation, and social network size and diversity. Functional aspects included perceptions of social support for physical activity from the social network in general as well as from family and friends specifically. Height, weight, and PA were objectively measured. From these, we derived Body Mass Index (BMI) and moderate-to-vigorous physical activity (MVPA). All regression models were stratified by gender, and included age, income, education, employment, marital status, physical limitations, and a neighborhood indicator. Greater social isolation was a significant predictor of lower BMI among men only. Among women only, social isolation was significantly associated with increased MVPA whereas, network diversity was significantly associated with reduced MVPA. Future research would benefit from in-depth qualitative investigations to understand how social networks may act to influence different types of physical activity among African Americans, as well as understand how they can be possible levers for health promotion and prevention.

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Contributes to research on the social environment and physical activity among African Americans.

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Social isolation was associated with lower BMI among men.

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Social isolation was associated with more physical activity among women.

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More social network diversity was associated with less physical activity among women.

The Feasibility of a Novel School Peer-Led Mentoring Model to Improve the Physical Activity Levels and Sedentary Time of Adolescent Girls: The Girls Peer Activity (G-PACT) Project

Regular physical activity (PA) is associated with numerous physical and psychological health benefits. Adolescents, specifically girls, are at risk of physical inactivity. To date, there is limited research on PA interventions involving peers, which could encourage more adolescent girls to engage in PA. The investigation aimed to evaluate the feasibility of a novel school three-tier peer-led mentoring model designed to improve PA levels and reduce sedentary time (ST) of adolescent girls. Two-hundred and forty-nine Year 9 adolescent girls (13⁻15 years old) from three UK secondary schools were invited to participate in a peer-led mentoring intervention (Girls Peer Activity (G-PACT) project). The peer-led mentoring model was delivered in all three schools. Two of the schools received an additional after-school PA component. PA and ST were assessed through wrist-worn accelerometry. Girls who received an exercise class after-school component significantly increased their whole day moderate-to-vigorous PA (MVPA) (3.2 min, p = 0.009, d = 0.33). Girls who received no after-school component significantly decreased their MVPA (3.5 min, p = 0.016, d = 0.36) and increased their ST (17.2 min, p = 0.006, d = 0.43). The G-PACT intervention demonstrated feasibility of recruitment and data collection procedures for adolescent girls. The peer-led mentoring model shows promise for impacting girls' MVPA levels when combined with an after-school club PA opportunity.

Statistical machine learning of sleep and physical activity phenotypes from sensor data in 96,220 UK Biobank participants

Current public health guidelines on physical activity and sleep duration are limited by a reliance on subjective self-reported evidence. Using data from simple wrist-worn activity monitors, we developed a tailored machine learning model, using balanced random forests with Hidden Markov Models, to reliably detect a number of activity modes. We show that physical activity and sleep behaviours can be classified with 87% accuracy in 159,504 minutes of recorded free-living behaviours from 132 adults. These trained models can be used to infer fine resolution activity patterns at the population scale in 96,220 participants. For example, we find that men spend more time in both low- and high- intensity behaviours, while women spend more time in mixed behaviours. Walking time is highest in spring and sleep time lowest during the summer. This work opens the possibility of future public health guidelines informed by the health consequences associated with specific, objectively measured, physical activity and sleep behaviours.

Are consumption of dairy products and physical activity independently related to bone mineral density of 6-year-old children? Longitudinal and cross-sectional analyses in a birth cohort from Brazil

OBJECTIVE

To evaluate cross-sectional and longitudinal associations of consumption of dairy products and physical activity (PA) with bone mineral density (BMD).

DESIGN

Cohort study with children from the 2004 Pelotas (Brazil) Birth Cohort.

SETTING

Pelotas, a medium-sized Brazilian city.

SUBJECTS

The study started in 2004 and mothers/children were interviewed/measured periodically from birth to age 6 years. PA was measured by maternal proxy at 4 and 6 years and by accelerometry at 6 years. Consumption of dairy products was measured using 24 h food recall (at 4 years) and FFQ (at 6 years). Total-body and lumbar-spine BMD (g/cm2) were measured by dual-energy X-ray absorptiometry.

RESULTS

At 6 years, BMD was measured in 3444 children and 2636 children provided data on objectively measured PA by accelerometry. Consumption of dairy products at 4 years was associated with higher lumbar-spine BMD at 6 years in boys, while current consumption was positively associated with BMD in both sexes (P < 0·001). PA assessed by maternal report at 4 and 6 years of age was associated with higher BMD at 6 years in boys. PA assessed by accelerometry was positively related to total-body and lumbar-spine BMD in boys and lumbar-spine BMD in girls. We did not find evidence for an interaction between PA and consumption of dairy products on BMD.

CONCLUSIONS

We observed positive and independent longitudinal and cross-sectional associations between consumption of dairy products and PA with BMD in the total body and at the lumbar spine in young children.

Children's Compliance With Wrist-Worn Accelerometry Within a Cluster-Randomized Controlled Trial: Findings From the Healthy Lifestyles Programme

PURPOSE

The purpose of this study was to assess children's compliance with wrist-worn accelerometry during a randomized controlled trial and to examine whether compliance differed by allocated condition or gender.

METHODS

A total of 886 children within the Healthy Lifestyles Programme trial were randomly allocated to wear a GENEActiv accelerometer at baseline and 18-month follow-up. Compliance with minimum wear-time criteria (≥10 h for 3 weekdays and 1 weekend day) was obtained for both time points. Chi-square tests were used to determine associations between compliance, group allocation, and gender.

RESULTS

At baseline, 851 children had usable data, 830 (97.5%) met the minimum wear-time criteria, and 631 (74.1%) had data for 7 days at 24 hours per day. At follow-up, 789 children had usable data, 745 (94.4%) met the minimum wear-time criteria, and 528 (67%) had complete data. Compliance did not differ by gender (baseline: χ² = 1.66, P = .2; follow-up: χ² = 0.76, P = .4) or by group at follow-up (χ² = 2.35, P = .13).

CONCLUSION

The use of wrist-worn accelerometers and robust trial procedures resulted in high compliance at 2 time points regardless of group allocation, demonstrating the feasibility of using precise physical activity monitors to measure intervention effectiveness.

Using open source accelerometer analysis to assess physical activity and sedentary behaviour in overweight and obese adults

Background

Physical activity and sedentary behaviour are difficult to assess in overweight and obese adults. However, the use of open-source, raw accelerometer data analysis could overcome this. This study compared raw accelerometer and questionnaire-assessed moderate-to-vigorous physical activity (MVPA), walking and sedentary behaviour in normal, overweight and obese adults, and determined the effect of using different methods to categorise overweight and obesity, namely body mass index (BMI), bioelectrical impedance analysis (BIA) and waist-to-hip ratio (WHR).

Methods

One hundred twenty adults, aged 24–60 years, wore a raw, tri-axial accelerometer (Actigraph GT3X+), for 3 days and completed a physical activity questionnaire (IPAQ-S). We used open-source accelerometer analyses to estimate MVPA, walking and sedentary behaviour from a single raw accelerometer signal. Accelerometer and questionnaire-assessed measures were compared in normal, overweight and obese adults categorised using BMI, BIA and WHR.

Results

Relationships between accelerometer and questionnaire-assessed MVPA (Rs = 0.30 to 0.48) and walking (Rs = 0.43 to 0.58) were stronger in normal and overweight groups whilst sedentary behaviour were modest (Rs = 0.22 to 0.38) in normal, overweight and obese groups. The use of WHR resulted in stronger agreement between the questionnaire and accelerometer than BMI and BIA. Finally, accelerometer data showed stronger associations with BMI, BIA and WHR (Rs = 0.40 to 0.77) than questionnaire data (Rs = 0.24 to 0.37).

Conclusions

Open-source, raw accelerometer data analysis can be used to estimate MVPA, walking and sedentary behaviour from a single acceleration signal in normal, overweight and obese adults. Our data supports the use of WHR to categorise overweight and obese adults. This evidence helps researchers obtain more accurate measures of physical activity and sedentary behaviour in overweight and obese populations.

Cross-sectional and longitudinal factors influencing physical activity of 65 to 75-year-olds: a pan European cohort study based on the survey of health, ageing and retirement in Europe (SHARE)

Background

The promotion of physical activity (PA) plays a major role for healthy ageing even in older age. There is a lack of cross-sectional and longitudinal studies explicitly dealing with barriers and drivers to PA in older adults. Therefore the aims of this study are a) to determine the prevalence of insufficient physical activity (IPA) in 65 to 75-year-olds in Europe and to identify factors associated with IPA in cross-section and b) to identify longitudinal risk factors for IPA in prior active persons.

Methods

This study is using data of the Survey of Health, Ageing and Retirement in Europe (SHARE). SHARE is a cross-national panel database including individual data of the non-institutionalised population aged 50+ from 27 European countries. For the present paper, we included a cohort that participated in all first four waves of SHARE (2004–2011) aged 65-to-75–years at wave four (male n = 1761, female n = 2085) from 10 European countries. To identify cross-sectional and longitudinal associations, we calculated prevalence odds ratios and hazard ratios with 95% confidence intervals.

Results

The prevalence of IPA in 65–75-year-olds varied widely between countries, ranging from 55.4% to 83.3% in women and from 46.6% to 73.7% in men. IPA was associated with several intrapersonal factors and strength of association was similar for men and women for almost all investigated factors. Statistically significant associated with IPA were socioeconomic factors as low educational level (own and parental) and financial difficulties (male: POR: 1.60: 95%-CI: 1.26–2.03; female: POR: 1.58; 95%-CI: 1.26–1.97) and health-related factors as e.g. number of chronic diseases (male: POR: 1.34: 95%-CI: 1.23–1.45; female: POR: 1.31; 95%-CI: 1.21–1.42). Interpersonal only the size of social network was associated with IPA (male and female: POR: 0.88, 95%-CI: 0.81–0.95). Longitudinally in a fully adjusted model, only grip strength (HR: 0.99; CI-95%: 0.98–0.99) and BMI (HR: 1.02; CI-95%: 1.00–1.04) were statistically significant risk factors for IPA.

Conclusions

PA promotion programs for older adults should incorporate the heterogeneity of health status and physical condition that can typically occur in this age group.

Electronic supplementary material

The online version of this article (10.1186/s12877-018-0781-8) contains supplementary material, which is available to authorized users.

What they say and what they do: comparing physical activity across the USA, England and the Netherlands

Background

Physical activity (PA) is important for maintaining health, but there are fundamental unanswered questions on how best it should be measured.

Methods

We measured PA in the Netherlands (n=748), the USA (n=540) and England (n=254), both by a 7 day wrist-worn accelerometer and by self-reports. The self-reports included a global self-report on PA and a report on the frequency of vigorous, moderate and mild activity.

Results

The self-reported data showed only minor differences across countries and across groups within countries (such as different age groups or working vs non-working respondents). The accelerometer data, however, showed large differences; the Dutch and English appeared to be much more physically active than Americans h (For instance, among respondents aged 50 years or older 38% of Americans are in the lowest activity quintile of the Dutch distribution). In addition, accelerometer data showed a sharp decline of PA with age, while no such pattern was observed in self-reports. The differences between objective measures and self-reports occurred for both types of self-reports.

Conclusion

It is clear that self-reports and objective measures tell vastly different stories, suggesting that across countries people use different response scales when answering questions about how physically active they are.

Correlates of accelerometer-assessed physical activity in pregnancy-The 2015 Pelotas (Brazil) Birth Cohort Study

Objective methods to measure physical activity (PA) have become available and widely used given the high degree of precision to evaluate PA. However, few studies have used accelerometers to measure PA during pregnancy, especially in low‐ and middle‐income countries. We assessed overall PA, moderate, vigorous, and moderate‐to‐vigorous physical activity (MVPA) objectively measured among pregnant women and their correlates in a population‐based study. PA was assessed for seven consecutive days using a raw triaxial wrist‐worn accelerometer in women interviewed around 16 and 24 weeks of gestation in the 2015 Pelotas (Brazil) Birth Cohort Study. The average acceleration, which expresses overall PA, was presented in milli‐g (1 mg = 0.001 g), and average time (min/day) spent in MVPA (>100 mg) was also analyzed in 5‐ and 10‐min bouts. Analyses were performed using linear regression. In total, 2317 women were included in the analyses. Overall PA was 27.6 mg. Pregnant women spent on average 14 min/day in MVPA and 0.4 min in vigorous PA. Time spent in MVPA and total PA were inversely associated with years in school and income, and were lower among women receiving advice to not exercise. MVPA was also inversely associated with age, lower among women living with a partner, and higher among non‐white women. The study indicated low levels of PA among pregnant women. The identified correlates may provide a framework to better understand factors influencing PA during pregnancy and thus inform future interventions.

Retrospectively assessed psychosocial working conditions as predictors of prospectively assessed sickness absence and disability pension among older workers

BACKGROUND

The aim was to explore the association between retrospectively assessed psychosocial working conditions during working life and prospectively assessed risk of sickness absence and disability pension among older workers.

METHODS

The prospective risk of register-based long-term sickness absence (LTSA) and disability pension was estimated from exposure to 12 different psychosocial work characteristics during working life among 5076 older workers from the CAMB cohort (Copenhagen Aging and Midlife Biobank). Analyses were censored for competing events and adjusted for age, gender, physical work environment, lifestyle, education, and prior LTSA.

RESULTS

LTSA was predicted by high levels of cognitive demands (HR 1.31 (95% CI 1.10-1.56)), high levels of emotional demands (HR 1.26 (95% CI 1.07-1.48)), low levels of influence at work (HR 1.30 (95% CI 1.03-1.64)), and high levels of role conflicts (HR 1.34 (95% CI 1.09-1.65)). Disability pension was predicted by low levels of influence at work (HR 2.73 (95% CI 1.49-5.00)) and low levels of recognition from management (HR 2.04 (95% CI 1.14-3.67)).

CONCLUSIONS

This exploratory study found that retrospectively assessed high cognitive demands, high and medium emotional demands, low influence at work, low recognition from management, medium role clarity, and high role conflicts predicted LTSA and/or disability pension.

Physical activity derived from questionnaires and wrist-worn accelerometers: comparability and the role of demographic, lifestyle, and health factors among a population-based sample of older adults

Background

Agreement between questionnaires and accelerometers to measure physical activity (PA) differs between studies and might be related to demographic, lifestyle, and health characteristics, including disability and depressive symptoms.

Methods

We included 1,410 individuals aged 51–94 years from the population-based Rotterdam Study. Participants completed the LASA Physical Activity Questionnaire and wore a wrist-worn accelerometer on the nondominant wrist for 1 week thereafter. We compared the Spearman correlation and disagreement (level and direction) for total PA across levels of demographic, lifestyle, and health variables. The level of disagreement was defined as the absolute difference between questionnaire- and accelerometer-derived PA, whereas the direction of disagreement was defined as questionnaire PA minus accelerometer PA. We used linear regression analyses with the level and direction of disagreement as outcome, including all demographic, lifestyle, and health variables in the model.

Results

We observed a Spearman correlation of 0.30 between questionnaire- and accelerometer-derived PA in the total population. The level of disagreement (ie, absolute difference) was 941.9 (standard deviation [SD] 747.0) minutes/week, and the PA reported by questionnaire was on average 529.4 (SD 1,079.5) minutes/week lower than PA obtained by the accelerometer. The level of disagreement decreased with higher educational levels. Additionally, participants with obesity, higher disability scores, and more depressive symptoms underestimated their self-reported PA more than their healthier counterparts.

Conclusion

We observed large differences in PA time derived from the LASA Physical Activity Questionnaire and the wrist-worn accelerometer. Differences between the methods were related to body-mass index, level of disability, and presence of depressive symptoms. Future studies using questionnaires and/or accelerometers should account for these differences.

Difference between tablet methods and paper questionnaire methods of conducting a survey with community-dwelling elderly

[Purpose] This study aimed to develop a tablet app that emulates paper questionnaires used in clinical care, and to verify the difference between the utility of tablet survey methods and paper questionnaire methods with elderly people. [Subjects and Methods] A tablet app was developed in the Java language. A questionnaire was provided to 30 community-dwelling elderly people. The subjects were randomly allocated to the group responding on the tablet (tablet group) or that responding to a paper-based questionnaire (questionnaire group). Assessed items included response time to questions, whether or not they had queries regarding the survey, and data input time. For the tablet group, a questionnaire was conducted regarding the operability of the tablet. [Results] There was no difference in response time between the two groups. Significantly more people in the tablet group had queries regarding the survey. Data input time was 426 seconds for the tablet group and 1268 seconds for the questionnaire group. In the survey regarding tablet operability, there were no negative opinions about the visibility of the screen. [Conclusion] Tablets can be used with elderly people to shorten the data input time. The present findings suggested that tablet surveys could be effective for a large-scale investigation.

Associations between seasonal meteorological conditions and the daily step count of adults in Yokohama, Japan: Results of year-round pedometer measurements in a large population

People's year-round interpersonal step count variations according to meteorological conditions are not fully understood, because complete year-round data from a sufficient sample of the general population are difficult to acquire. This study examined the associations between meteorological conditions and objectively measured step counts using year-round data collected from a large cohort (N = 24,625) in Yokohama, Japan from April 2015 to March 2016.

Two-piece linear regression analysis was used to examine the associations between the monthly median daily step count and three meteorological indices (mean values of temperature, temperature-humidity index (THI), and net effective temperature (NET)).

The number of steps per day peaked at temperatures between 19.4 and 20.7 °C. At lower temperatures, the increase in steps per day was between 46.4 and 52.5 steps per 1 °C increase. At temperatures higher than those at which step counts peaked, the decrease in steps per day was between 98.0 and 187.9 per 1 °C increase. Furthermore, these effects were more obvious in elderly than non-elderly persons in both sexes. A similar tendency was seen when using THI and NET instead of temperature. Among the three meteorological indices, the highest R² value with step counts was observed with THI in all four groups.

Both high and low meteorological indices discourage people from walking and higher values of the indices adversely affect step count more than lower values, particularly among the elderly. Among the three indices assessed, THI best explains the seasonal fluctuations in step counts.

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We used year-round data collected from a large cohort (N = 24,625).

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Both high and low meteorological indices discourage people from walking.

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Effects were more obvious in elderly than non-elderly persons in both sexes.

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Temperature-humidity index (THI) best explains the seasonal fluctuations in steps.

Attitudes and Barriers to Healthy Diet and Physical Activity: A Latent Profile Analysis

Healthy diet and physical activity (PA) prevent and reduce chronic disease. Social cognitive theory delineates multiple attitudes and barriers that influence these behaviors. Understanding covariation in these attitudes and barriers is complex. We examined whether individuals could be grouped into a small number of categories that are easier to study. Interviews were conducted with 982 adults from two low-income, predominantly African American neighborhoods in the same city. Social cognitive constructs, including self-efficacy, social norms, and internal and external barriers to diet and exercise, and walking were self-reported. We measured moderate to vigorous physical activity with accelerometers and diet with 24-hour recalls. We conducted a latent profile analysis of attitudes and barriers to diet and PA and identified four classes: (a) moderate diet and negative exercise attitudes, where participants were roughly average on dietary attitudes but reported exercise-related challenges, including lower social support, outcome expectancies, physical functioning, and self-efficacy; (b) few barriers and benefits of healthy diet and exercise, where participants reported fewer barriers and lower outcome expectancies for diet and PA; (c) moderate overall attitudes, where participants had average scores on most indicators but below-average exercise self-efficacy and slightly more exercise barriers; and (d) positive overall attitudes, characterized by more positive attitudes toward both diet and PA across most domains, particularly regarding self-efficacy to overcome exercise barriers. These profiles could inform efforts to tailor individual-level interventions for diet and PA of persons at high risk of chronic diseases.

Retrospectively assessed physical work environment during working life and risk of sickness absence and labour market exit among older workers

Objective

To determine the prospective association between retrospectively assessed physical work environment during working life and prospectively assessed sickness absence and labour market exit among older workers.

Methods

Using Cox regression analyses we estimated the 4-year to 6-year prospective risk of register-based long-term sickness absence (LTSA), disability pension, early retirement and unemployment from exposure to different physical work environmental factors during working life among 5076 older workers (age 49–63 at baseline) from the Copenhagen Aging and Midlife Biobank cohort.

Results

Very hard physical work throughout working life was a risk factor for LTSA (HR 1.66,95% CI 1.32 to 2.07), disability pension (HR 2.21,95% CI 1.04 to 4.72) and early retirement (HR 1.57,95% CI 1.13 to 2.17). Both short-term (<10 years) and long-term (≥20 years) exposures to lifting or carrying of heavy burdens predicted the risk of LTSA (HRs 1.49–1.56) and disability pension (HRs 2.26–3.29). In contrast, exposure to dust was associated with LTSA and disability pension only following 20 or more exposure years.

Conclusions

Retrospectively assessed hard physical work during working life and exposure to several factors in the physical work environment, especially heavy lifting, were important for labour market exit and sickness absence. This study underscores the importance of reducing physical work exposures throughout the working life course for preventing sickness absence and premature exit from the labour market.

Does retirement benefit health?

Currently large postwar baby-boomer generations are retiring from labor market. Transition to retirement is considered an important turning point in life which is accompanied by changes in many aspects of life such as time availability, daily routines, income streams and social networks. Recent longitudinal studies suggest that retirement can have a major influence on people's health behaviors, health and quality of life. Retirement could also be an opportune time at which to intervene with health-promotion activities and support healthy and active aging.

Comparing motivational, self-regulatory and habitual processes in a computer-tailored physical activity intervention in hospital employees - protocol for the PATHS randomised controlled trial

BACKGROUND

Most people do not engage in sufficient physical activity to confer health benefits and to reduce risk of chronic disease. Healthcare professionals frequently provide guidance on physical activity, but often do not meet guideline levels of physical activity themselves. The main objective of this study is to develop and test the efficacy of a tailored intervention to increase healthcare professionals' physical activity participation and quality of life, and to reduce work-related stress and absenteeism. This is the first study to compare the additive effects of three forms of a tailored intervention using different techniques from behavioural theory, which differ according to their focus on motivational, self-regulatory and/or habitual processes.

METHODS/DESIGN

Healthcare professionals (N = 192) will be recruited from four hospitals in Perth, Western Australia, via email lists, leaflets, and posters to participate in the four group randomised controlled trial. Participants will be randomised to one of four conditions: (1) education only (non-tailored information only), (2) education plus intervention components to enhance motivation, (3) education plus components to enhance motivation and self-regulation, and (4) education plus components to enhance motivation, self-regulation and habit formation. All intervention groups will receive a computer-tailored intervention administered via a web-based platform and will receive supporting text-messages containing tailored information, prompts and feedback relevant to each condition. All outcomes will be assessed at baseline, and at 3-month follow-up. The primary outcome assessed in this study is physical activity measured using activity monitors. Secondary outcomes include: quality of life, stress, anxiety, sleep, and absenteeism. Website engagement, retention, preferences and intervention fidelity will also be evaluated as well as potential mediators and moderators of intervention effect.

DISCUSSION

This is the first study to examine a tailored, technology-supported intervention aiming to increase physical activity in healthcare professionals. The study will evaluate whether including additional theory-based behaviour change techniques aimed at promoting motivation, self-regulation and habit will lead to increased physical activity participation relative to information alone. The online platform developed in this study has potential to deliver efficient, scalable and personally-relevant intervention that can be translated to other occupational settings.

TRIAL REGISTRATION

Australian New-Zealand Clinical Trial Registry: ACTRN12616000462482, submitted 29/03/2016, prospectively registered 8/04/2016.

Predictors of Segmented School Day Physical Activity and Sedentary Time in Children from a Northwest England Low-Income Community

Background: Schools have been identified as important settings for health promotion through physical activity participation, particularly as children are insufficiently active for health. The aim of this study was to investigate the child and school-level influences on children′s physical activity levels and sedentary time during school hours in a sample of children from a low-income community; Methods: One hundred and eighty-six children (110 boys) aged 9–10 years wore accelerometers for 7 days, with 169 meeting the inclusion criteria of 16 h∙day⁻¹ for a minimum of three week days. Multilevel prediction models were constructed to identify significant predictors of sedentary time, light, and moderate to vigorous physical activity during school hour segments. Child-level predictors (sex, weight status, maturity offset, cardiorespiratory fitness, physical activity self-efficacy, physical activity enjoyment) and school-level predictors (number on roll, playground area, provision score) were entered into the models; Results: Maturity offset, fitness, weight status, waist circumference-to-height ratio, sedentary time, moderate to vigorous physical activity, number of children on roll and playground area significantly predicted physical activity and sedentary time; Conclusions: Research should move towards considering context-specific physical activity and its correlates to better inform intervention strategies.