Estimation of Physical Activity Energy Expenditure during Free-Living from Wrist Accelerometry in UK Adults

Association between physical activity and diabetes control: multiple cross-sectional studies and a prospective study in a population-based, Swiss cohort

INTRODUCTION

Physical activity (PA) is recommended in patients with type 2 diabetes mellitus (T2DM) to improve their glycaemic control. We aimed to assess PA levels among participants with controlled and uncontrolled T2DM.

RESEARCH DESIGN AND METHODS

Three cross-sectional analyses of a prospective cohort conducted in Lausanne, Switzerland. PA levels (sedentary, light, moderate and vigorous) were either self-reported via questionnaire (first and second survey) or objectively assessed using accelerometry (second and third survey). T2DM control was defined as glycaemia <7.0 mmol/L or glycated haemoglobin <6.5% (48 mmol/mol).

RESULTS

Data from 195 (30.3% women), 199 (30.1% women) and 151 (44.4% women) participants with T2DM were analysed in the first (2009-2012), second (2014-2017) and third (2018-2021) surveys. Approximately half of the participants did not have controlled glycaemia. Using subjective data, over 90% (first survey) and 75% (second survey) of participants reported moderate and vigorous PA >150 min/week. After multivariable adjustment, no differences were found regarding all types of self-reported PA levels between controlled and uncontrolled participants. Objective assessment of PA led to considerable differences according to the software used: 90% and 20% of participants with moderate and vigorous PA >150 min/week, respectively. After multivariable adjustment, no differences were found for all PA levels between controlled and uncontrolled participants, irrespective of the analytical procedure used. Using glycated haemoglobin, almost two-thirds of participants were considered as uncontrolled, and no differences were found for objectively assessed PA between controlled and uncontrolled participants.

CONCLUSIONS

No differences in PA levels were found between participants with controlled and uncontrolled T2DM.

Associations between leisure-time physical activity and the prevalence and incidence of osteoporosis disease: Cross-sectional and prospective findings from the UK biobank

BACKGROUND

Previous studies underscore the protective role of physical activity (PA) in bone health, yet the relationship between different PA categories and osteoporosis risk remains less explored. Understanding the relationships helps tailor health recommendations and policies to maximize the effects of preventing osteoporosis.

METHODS

The cross-sectional study involves 488,403 UK Biobank participants with heel quantitative ultrasound-estimated bone mineral density (eBMD) data. The longitudinal cohort involves 471,394 UK Biobank participants without initial osteoporosis and with follow-up records. PA exposure categories in our study included sedentary behavior (SB), total PA (TPA), and different category-specific PA including household, leisure, and work PA. The cases of osteoporosis were assessed using the International Classification of Diseases, 10th revision (ICD-10). The linear, logistic, and Cox proportional hazard regression models were used in our study.

RESULTS

In the cross-sectional study, 15,818 (3.28 %) participants had osteoporosis. TPA levels have a positive correlation with eBMD and a negative correlation with osteoporosis prevalence. Among different categories of PA, higher levels of leisure PA were correlated with increased eBMD and a lower osteoporosis risk (leisure PA: OR: 0.83, 95 % CI: 0.79 to 0.86;). In the longitudinal study, 16,058 (17.6 % male, 82.4 % female) (3.41 %) individuals developed osteoporosis during an average follow-up of 13 years. We observed consistent protective effects of high levels of PA on osteoporosis incidence risk, particularly within the category of leisure PA (TPA: HR: 0.78, 95 % CI: 0.74 to 0.82; leisure PA:HR: 0.83, 95 % CI: 0.80 to 0.87). Such associations are independent of genetic predisposition, with no evidence of gene-PA interactions, and keep steady among individuals using drugs affecting bone-density. Moreover, among different leisure PA items, strenuous sports, other exercises, and walking for pleasure conferred a substantial protective effect against osteoporosis. Additionally, non-elderly individuals and males exhibited lower osteoporosis risk from PA.

CONCLUSION

This study highlights activity categories differently associated with the risk of osteoporosis. Adherence to frequent leisure PA may have a protective effect against osteoporosis. Such associations are independent of genetic susceptibility to osteoporosis and keep steady among individuals using drugs affecting bone-density. This highlights that leisure PA could be suggested as a more effective intervention in the primary prevention of osteoporosis.

Data Analytics in Physical Activity Studies With Accelerometers: Scoping Review

BACKGROUND

Monitoring free-living physical activity (PA) through wearable devices enables the real-time assessment of activity features associated with health outcomes and provision of treatment recommendations and adjustments. The conclusions of studies on PA and health depend crucially on reliable statistical analyses of digital data. Data analytics, however, are challenging due to the various metrics adopted for measuring PA, different aims of studies, and complex temporal variations within variables. The application, interpretation, and appropriateness of these analytical tools have yet to be summarized.

OBJECTIVE

This research aimed to review studies that used analytical methods for analyzing PA monitored by accelerometers. Specifically, this review addressed three questions: (1) What metrics are used to describe an individual's free-living daily PA? (2) What are the current analytical tools for analyzing PA data, particularly under the aims of classification, association with health outcomes, and prediction of health events? and (3) What challenges exist in the analyses, and what recommendations for future research are suggested regarding the use of statistical methods in various research tasks?

METHODS

This scoping review was conducted following an existing framework to map research studies by exploring the information about PA. Three databases, PubMed, IEEE Xplore, and the ACM Digital Library, were searched in February 2024 to identify related publications. Eligible articles were classification, association, or prediction studies involving human PA monitored through wearable accelerometers.

RESULTS

After screening 1312 articles, 428 (32.62%) eligible studies were identified and categorized into at least 1 of the following 3 thematic categories: classification (75/428, 17.5%), association (342/428, 79.9%), and prediction (32/428, 7.5%). Most articles (414/428, 96.7%) derived PA variables from 3D acceleration, rather than 1D acceleration. All eligible articles (428/428, 100%) considered PA metrics represented in the time domain, while a small fraction (16/428, 3.7%) also considered PA metrics in the frequency domain. The number of studies evaluating the influence of PA on health conditions has increased greatly. Among the studies in our review, regression-type models were the most prevalent (373/428, 87.1%). The machine learning approach for classification research is also gaining popularity (32/75, 43%). In addition to summary statistics of PA, several recent studies used tools to incorporate PA trajectories and account for temporal patterns, including longitudinal data analysis with repeated PA measurements and functional data analysis with PA as a continuum for time-varying association (68/428, 15.9%).

CONCLUSIONS

Summary metrics can quickly provide descriptions of the strength, frequency, and duration of individuals' overall PA. When the distribution and profile of PA need to be evaluated or detected, considering PA metrics as longitudinal or functional data can provide detailed information and improve the understanding of the role PA plays in health. Depending on the research goal, appropriate analytical tools can ensure the reliability of the scientific findings.

Reflections on four decades of physical activity epidemiology

•Broad topics in physical activity (PA) epidemiology have remained the same over 40 years; specific issues and questions have changed and challenges remain. •Accelerometry has made many advances in PA measurement, but created new methodological challenges. •The benefit of regular PA for a wide array of health outcomes has been well-established, but specificity is still needed about dose response relations. •Interventions in the population have led to increased prevalence of recommended levels of PA, but prevalence is still less than optimal and there are racial and ethnic disparities.

Associations of objective sleep duration and physical activity with risk of heart failure: A prospective cohort study

OBJECTIVE

This study aimed to investigate the independent and joint associations of accelerometer-derived sleep duration and physical activity (PA) in different intensities with the risk of incident heart failure (HF).

METHODS

The study included 89,572 participants (mean age 62.2 ± 7.8 years, 42.8% male) from the UK Biobank. Sleep duration (short: <6 h/day; normal: 6-8 h/day; long: >8 h/day) and PA [total PA, light PA (LPA), moderate-to-vigorous PA (MVPA), vigorous PA (VPA)] were measured using accelerometers over 7 days. MVPA and VPA were categorized according to the World Health Organization's recommended levels, while LPA and total PA were categorized based on the median. HF cases were identified through hospital records or death registries.

RESULTS

Over a 7-year follow-up period, 1324 participants (2.1%; incidence rate, 2.1 per 1000 person-years) developed HF. Short, but not long, sleep duration was linked to a 33% increased risk of HF [hazard ratio (HR) 1.33, 95% confidence interval (CI): 1.11-1.59]. This increased risk associated with short sleep could be mitigated by increasing PA, especially to the levels of recommended MVPA or VPA. In joint analyses, compared to participants meeting the recommended MVPA and with normal sleep duration, those not meeting the MVPA recommendation and with short sleep had the highest HF risk (HR 1.78, 95% CI: 1.42-2.25).

CONCLUSIONS

Accelerometer-derived short, but not long, sleep duration was associated with a higher risk of incident HF. Engaging in sufficient PA, especially recommended MVPA or VPA, can partially mitigate this risk.

Daytime napping and the incidence of Parkinson's disease: a prospective cohort study with Mendelian randomization

BACKGROUND

The causal relationship between daytime napping and the risk of Parkinson's disease (PD) remains unclear, with prospective studies providing limited evidence. This study investigated the association between daytime napping frequency and duration and PD incidence and explored the causality relationship between this association by conducting Mendelian randomization (MR) analysis.

METHODS

This prospective cohort study included 393,302 participants, and accelerometer-measured daytime napping data were available only for 78,141 individuals. Cox proportional hazards regression was used to estimate the association between the daytime napping frequency and duration and the PD risk. The role of the systemic immune-inflammation index (SII) in the association between daytime napping frequency and PD risk was assessed through mediation analyses. Moreover, the causal association between the daytime napping frequency and the PD risk was preliminarily explored by conducting two-sample MR analyses.

RESULTS

The median follow-up duration was 12.18 years. The participants who reported napping sometimes or usually exhibited a significantly higher PD risk than those who never/rarely napped during the day [sometimes: hazard ratio (HR), 1.13; 95% confidence interval (CI), 1.03-1.23; usually: HR, 1.33; 95% CI, 1.14-1.55], and SII played a mediating role in this association. However, the MR analyses did not indicate that the daytime napping frequency and PD risk were significantly associated. The participants napping for over 1 h exhibited a significantly elevated PD risk (HR, 1.54; 95% CI, 1.11-2.16). Moreover, no significant interaction was identified between napping frequency or duration and genetic susceptibility to PD (P for interaction > 0.05).

CONCLUSIONS

In this study, increased daytime napping frequency and duration were associated with an increased PD risk, but no causal relationship was observed between napping frequency and PD risk in the MR analysis. Larger GWAS-based cohort studies and MR studies are warranted to explore potential causal relationships.

Physical Activity Patterns Within Dementia Care Dyads

Previous research has explored the physical activity habits of people with dementia and their family carers separately, with little consideration of how physical habits are associated within dyads. In this observational study, we sought to explore the relationship between people with dementia and their carers' physical activity, at a group level and at a dyadic level. Twenty-six participant dyads (persons with dementia and their carer spouses) were asked to wear an accelerometer for 30 days continuously. Comparisons were made at a group level and a dyadic level. People with dementia did not participate in significantly more moderate to vigorous physical activity (M = 15.44 min/day; SD = 14.40) compared with carers (M = 17.95 min/day; SD = 17.01). Within dyads, there were moderately strong associations between daily moderate to vigorous physical activity (r = .48-.54), but not with overall activity levels (r = .24). Despite physical activity habits remaining relatively low within people with dementia and carers, respectively, moderate to vigorous physical activity levels appear to be correlated within dyads. Understanding mutual influence on physical activity levels within dyads is an important pathway to promote an active lifestyle.

Adherence to 2020 ESC recommendations on physical activity in a population with different cardiovascular risk levels: A prospective population-based study from the CoLaus/PsyCoLaus study

Introduction

In 2020, the European Society of Cardiology (ESC) recommends 150 min of moderate or 75 min of vigorous-intensity PA per week. While general population PA adherence is suboptimal, its status among those with previous ASCVD or high ASCVD risk remains unknown. We aimed to assess objective adherence to ESC PA recommendations using accelerometer-based measurement among these populations.

Methodology

We used data from the Swiss CoLaus|PsyCoLaus cohort study (2014-2016). PA was measured using a 14-day wrist accelerometer. Adherence was defined as > 80 % of recommended PA achievement. Adherence was investigated separately among participants with previous ASCVD and among cardiovascular risk groups (based on the Systematic Coronary Risk Evaluation SCORE-1 and more recent SCORE2) with simple and multivariable logistic regressions. Participants' characteristics were also evaluated as independent factors after adjustment.

Results

We studied 1867 participants (median age: 61.2 years, 51.3 % female). ESC PA Adherence reached 55.5 % overall, and 37 % in those with previous ASCVD. Multivariable analysis showed no significant association between previous ASCVD or high cardiovascular risk and PA adherence (Odds ratio adjusted [ORa] 0.9, 95 % Confidence Interval [CI] 0.6-1.4 and ORa 0.7, 95 % CI 0.4-1.2, respectively). Age (≥60 years old), obesity, smoking, chronic renal disease, hypertension, diabetes and benzodiazepine use were significantly associated with lower likelihood of PA adherence in multivariable logistic regression.

Conclusion

Adherence to ESC PA guidelines, particularly in participants with higher cardiovascular risk, was poor. Since PA adherence was associated with modifiable risk factors (e.g., obesity, smoking, and benzodiazepine use), maintained efforts to implement the ESC recommendations are advised.

Physical activity and lung function association in a healthy community-dwelling European population

BACKGROUND

The association of physical activity (PA) and lung function (LF) varies from no measurable effect to delayed LF decline. We assessed the association between accelerometery-assessed PA and LF in a sample of apparently healthy, community-dwelling subjects.

METHODS

We included two cross-sectional studies using data from the PneumoLaus study (2014-17 and 2018-21), conducted in Lausanne, Switzerland. PA was assessed by accelerometry and categorised as inactivity, light, moderate or vigorous. Forced expiratory volume in 1 second (FEV1), forced volume capacity (FVC) and maximal mid-expiratory flow (MMEF) were measured by spirometry and expressed in percentage of predicted value (PV).

RESULTS

Overall, 1'910 (54.7% women, 62.0 ± 9.7 years) and 1'174 (53.4% women, 65.8 ± 9.5 years) participants were included in the first and the second surveys, respectively. In both surveys, moderate and vigorous PA showed a weak but significant correlation with FEV1 in percentage (PV) (R = 0.106 and 0.132 for the first and 0.111 and 0.125 for the second surveys, p < 0.001). Similar correlations with FVC (p < 0.001) were found. Associations held irrespective of smoking status and remained after multivariable adjustment. Fewer associations were detected between LF and light PA or between MMEF and PA.

CONCLUSION

Moderate and vigorous intensity PA are associated with increased LF regardless of smoking status in apparently healthy community-dwelling European population. These associations are statistically but not clinically significant due to the small correlation coefficients (R < 0.30), corresponding to a weak association.

Accelerometer-derived physical activity and the risk of death, heart failure, and stroke in patients with atrial fibrillation: a prospective study from UK Biobank

OBJECTIVE

Data on cardiovascular outcomes according to objectively measured physical activity (PA) in patients with atrial fibrillation (AF) are scarce. This study explored the associations between PA derived from wrist-worn accelerometers and the risk of death, incident heart failure (HF), and incident stroke in patients with AF.

METHODS

From 37 990 patients with AF in UK Biobank, 2324 patients with accelerometer data were included. Weekly moderate-to-vigorous PA (MVPA) duration was computed from accelerometer data. The primary outcome was all-cause mortality. Secondary outcomes were cardiovascular mortality, incident HF, and incident stroke. Restricted cubic splines estimated the dose-response associations between MVPA duration and the outcomes. The adjusted HRs (aHRs) of the outcomes according to adherence to PA standard guidelines (performing MVPA≥150 min/week) were also evaluated.

RESULTS

The mean age was 66.9±6.2 years and 64.9% were male. During a median follow-up of 6.7 years, there were 181 all-cause deaths, 62 cardiovascular deaths, 225 cases of incident HF, and 91 cases of incident stroke; the overall incidence rate per 1000 patient-years was 11.76, 4.03, 15.16 and 5.99, respectively. There was a linear inverse dose-response relationship between MVPA (≥108 min/week) and all-cause mortality. Performing MVPA for 105-590 min/week was associated with a lower risk of HF than those with no measurable MVPA. The risk of stroke and cardiovascular mortality was not associated with MVPA. Performing guideline-adherent MVPA was related to a 30% lower risk of all-cause mortality (aHR: 0.70 (0.50-0.98), p=0.04) and 33% lower risk of HF (aHR 0.67 (0.49-0.93), p=0.02).

CONCLUSION

In patients with AF, accelerometer-derived PA data supports lower risks of all-cause mortality and HF according to a greater level of MVPA and adherence to PA guidelines. Regular MVPA should be encouraged in patients with AF as a part of integrated management.

Associations between actigraphy-measured sleep duration, continuity, and timing with mortality in the UK Biobank

STUDY OBJECTIVES

To examine the associations between sleep duration, continuity, timing, and mortality using actigraphy among adults.

METHODS

Data were from a cohort of 88 282 adults (40-69 years) in UK Biobank that wore a wrist-worn triaxial accelerometer for 7 days. Actigraphy data were processed to generate estimates of sleep duration and other sleep characteristics including wake after sleep onset (WASO), number of 5-minute awakenings, and midpoint for sleep onset/wake-up and the least active 5 hours (L5). Data were linked to mortality outcomes with follow-up to October 31, 2021. We implemented Cox models (hazard ratio, confidence intervals [HR, 95% CI]) to quantify sleep associations with mortality. Models were adjusted for demographics, lifestyle factors, and medical conditions.

RESULTS

Over an average of 6.8 years 2973 deaths occurred (1700 cancer, 586 CVD deaths). Overall sleep duration was significantly associated with risk for all-cause (p < 0.01), cancer (p < 0.01), and CVD (p = 0.03) mortality. For example, when compared to sleep durations of 7.0 hrs/d, durations of 5 hrs/d were associated with a 29% higher risk for all-cause mortality (HR: 1.29 [1.09, 1.52]). WASO and number of awakenings were not associated with mortality. Individuals with L5 early or late midpoints (<2:30 or ≥ 3:30) had a ~20% higher risk for all-cause mortality, compared to those with intermediate L5 midpoints (3:00-3:29; p ≤ 0.01; e.g. HR ≥ 3:30: 1.19 [1.07, 1.32]).

CONCLUSIONS

Shorter sleep duration and both early and late sleep timing were associated with a higher mortality risk. These findings reinforce the importance of public health efforts to promote healthy sleep patterns in adults.

Actigraphy-derived measures of sleep and risk of prostate cancer in the UK Biobank

BACKGROUND

Studies of sleep and prostate cancer are almost entirely based on self-report, with limited research using actigraphy. Our goal was to evaluate actigraphy-measured sleep and prostate cancer and to expand on findings from prior studies of self-reported sleep.

METHODS

We prospectively examined 34 260 men without a history of prostate cancer in the UK Biobank. Sleep characteristics were measured over 7 days using actigraphy. We calculated sleep duration, onset, midpoint, wake-up time, social jetlag (difference in weekend-weekday sleep midpoints), sleep efficiency (percentage of time spent asleep between onset and wake-up time), and wakefulness after sleep onset. Cox proportional hazards models were used to estimate covariate-adjusted hazards ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Over 7.6 years, 1152 men were diagnosed with prostate cancer. Sleep duration was not associated with prostate cancer risk. Sleep midpoint earlier than 4:00 am was not associated with prostate cancer risk, though sleep midpoint of 5:00 am or later was suggestively associated with lower prostate cancer risk but had limited precision (earlier than 4:00 am vs 4:00-4:59 am HR = 1.00, 95% CI = 0.87 to 1.16; 5:00 am or later vs 4:00-4:59 am HR = 0.79, 95% CI = 0.57 to 1.10). Social jetlag was not associated with greater prostate cancer risk (1 to <2 hours vs <1 hour HR = 1.06, 95% CI = 0.89 to 1.25; ≥2 hours vs <1 hour HR = 0.90, 95% CI = 0.65 to 1.26). Compared with men who averaged less than 30 minutes of wakefulness after sleep onset per day, men with 60 minutes or more had a higher risk of prostate cancer (HR = 1.20, 95% CI = 1.00 to 1.43).

CONCLUSIONS

Of the sleep characteristics studied, higher wakefulness after sleep onset-a measure of poor sleep quality-was associated with greater prostate cancer risk. Replication of our findings between wakefulness after sleep onset and prostate cancer are warranted.

It needs more than a myocardial infarction to start exercising: the CoLaus|PsyCoLaus prospective study

BACKGROUND

Increased physical activity (PA) is recommended after an acute coronary event to prevent recurrences. Whether patients with acute coronary event actually increase their PA has not been assessed using objective methods such as accelerometer. We aimed to assess the subjectively and objectively measured physical activity (PA) levels of patients before and after an acute coronary event.

METHODS

Data from the three follow-up surveys of a prospective study conducted in Lausanne, Switzerland. Self-reported PA was assessed by questionnaire in the first (2009-2012) and second (2014-2017) follow-ups. Objective PA was assessed by a wrist-worn accelerometer in the second and third (2018-2021) follow-ups. Participants who developed an acute coronary event between each survey period were considered as eligible. PA levels were compared before and after the event, and changes in PA levels were also compared between participants who developed an acute event with three gender and age-matched healthy controls.

RESULTS

For self-reported PA, data from 43 patients (12 women, 64 ± 9 years) were used. No differences were found for all PA levels expressed in minutes/day before and after the event: moderate PA, median and [interquartile range] 167 [104-250] vs. 153 [109-240]; light PA: 151 [77-259] vs. 166 [126-222], and sedentary behaviour: 513 [450-635] vs. 535 [465-642] minutes/day. Comparison with gender- and age-matched healthy controls showed no differences regarding trends in reported PA. For accelerometer-assessed PA, data from 32 patients (16 women, 66 ± 9 years) were used. No differences were found for all PA levels expressed in minutes/day before and after the event: moderate PA: 159 [113-189] vs. 141 [111-189]; light PA: 95.8 [79-113] vs. 95.9 [79-117], and sedentary behaviour: 610 [545-659] vs. 602 [540-624]. Regarding the comparison with gender- and age-matched healthy controls, controls had an increase in accelerometer-assessed sedentary behaviour as % of day: multivariable adjusted average standard error 2.7 ± 0.6, while no increase was found for cases: 0.1 ± 1.1; no differences were found for the other PA levels.

CONCLUSION

Patients do not seem to change their PA levels after a first coronary event. Our results should be confirmed in larger samples.

Validation of a Zio XT Patch Accelerometer for the Objective Assessment of Physical Activity in the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Combination devices to monitor heart rate/rhythms and physical activity are becoming increasingly popular in research and clinical settings. The Zio XT Patch (iRhythm Technologies, San Francisco, CA, USA) is US Food and Drug Administration (FDA)-approved for monitoring heart rhythms, but the validity of its accelerometer for assessing physical activity is unknown.

OBJECTIVE

To validate the accelerometer in the Zio XT Patch for measuring physical activity against the widely-used ActiGraph GT3X.

METHODS

The Zio XT and ActiGraph wGT3X-BT (Actigraph, Pensacola, FL, USA) were worn simultaneously in two separately-funded ancillary studies to Visit 6 of the Atherosclerosis Risk in Communities (ARIC) Study (2016-2017). Zio XT was worn on the chest and ActiGraph was worn on the hip. Raw accelerometer data were summarized using mean absolute deviation (MAD) for six different epoch lengths (1-min, 5-min, 10-min, 30-min, 1-h, and 2-h). Participants who had ≥3 days of at least 10 h of valid data between 7 a.m-11 p.m were included. Agreement of epoch-level MAD between the two devices was evaluated using correlation and mean squared error (MSE).

RESULTS

Among 257 participants (average age: 78.5 ± 4.7 years; 59.1% female), there were strong correlations between MAD values from Zio XT and ActiGraph (average r: 1-min: 0.66, 5-min: 0.90, 10-min: 0.93, 30-min: 0.93, 1-h: 0.89, 2-h: 0.82), with relatively low error values (Average MSE × 106: 1-min: 349.37 g, 5-min: 86.25 g, 10-min: 56.80 g, 30-min: 45.46 g, 1-h: 52.56 g, 2-h: 54.58 g).

CONCLUSIONS

These findings suggest that Zio XT accelerometry is valid for measuring duration, frequency, and intensity of physical activity within time epochs of 5-min to 2-h.

Total and temporal patterning of physical activity in adolescents and associations with mental wellbeing

BACKGROUND

There is limited understanding of the extent to which differences in physical activity across the day and week may be associated with mental wellbeing. Such an understanding is needed for better targeting of interventions. In this study, we describe total and temporal patterning of physical activity across the week in adolescents (age 13-14y) and assess their prospective associations with mental wellbeing.

METHODS

1,983 13-14-year-old adolescent participants based in Cambridgeshire and Essex, recruited between 2016 and 2017 into the Get Others Active Trial provided data at baseline and 4 months. Physical activity was measured at baseline using wrist-worn accelerometers across different time segments (whole week, weekday schooltime, weekday out of school, and weekend), and operationalized as average movement-related acceleration for each time segment. Mental Wellbeing at baseline and 4 months was measured using the Warwick Edinburgh MentalWellbeing Scale. Associations between physical activity across different time segments (whole week, weekday schooltime, weekday out of school, and weekend) and mental wellbeing at 4 months were investigated using sex-stratified multi-level regression models, adjusted for covariates, and both adjusted and unadjusted for baseline mental wellbeing.

RESULTS

Our analyses found positive associations between physical activity and mental wellbeing at 4 months, unadjusted for baseline wellbeing. Among girls, positive associations were shown when considering physical activity across the whole week 0.07 (95% CI, 0.03-0.12), and across all separate time periods studied: weekday schooltime 0.07 (95% CI, 0.02-0.11), weekday out-of-school time 0.07 (95% CI, 0.03-0.12), and weekend 0.07 (95% CI, 0.02-0.11). For boys, similar associations were observed for activity across the week 0.07 (95% CI, 0.03-0.11), during weekday schooltime 0.08 (95% CI, 0.04-0.12), and weekday out-of-school time 0.07 (95% CI, 0.03-0.11), but not the weekend 0.01 (95% CI, -0.03-0.05). For both girls and boys, associations were attenuated below significance after adjusting for baseline wellbeing.

CONCLUSIONS

This longitudinal analysis showed positive associations between physical activity and later mental wellbeing in both male and female adolescents across most time segments. Higher physical activity throughout the week may be associated with better mental wellbeing in the adolescent population. Further research is required to understand determinants of change in wellbeing over time.

TRIAL REGISTRATION

Registration Number: ISRCTN31583496. Registered: 18/02/2014.

Replacing device-measured sedentary time with physical activity is associated with lower risk of coronary heart disease regardless of genetic risk

BACKGROUND

Excess sedentary time (ST) is recognized as an important modifiable risk factor for coronary heart disease (CHD). However, whether the associations of genetic susceptibility with CHD incidence can be modified by replacing wearable-device-measured ST with physical activity (PA) is unknown.

OBJECTIVES

To examine the associations of wearable-device-measured ST replaced by PA with incident CHD across strata of genetic susceptibility.

METHODS

This study included 77,500 White British (57% female) with valid wrist-worn accelerometry and without prevalent CHD/stroke from UK Biobank. Genetic susceptibility to CHD was quantified through weighted polygenic risk scores for CHD based on 300 single-nucleotide polymorphisms. Wrist-worn accelerometer data were used to derive ST, light PA, and moderate-to-vigorous PA (MVPA).

RESULTS

Reallocation of 60 min/day of ST into the same amount of MVPA was associated with approximately 9% lower relative risk of CHD for all participants and across strata of genetic risk: replacement of 1 min/day of ST associated with <1% lower relative risk of CHD. No evidence of interaction (p: 0.784) was found between genetic risk and ST for CHD risk. Reallocating 60 min/day of ST into the same MVPA time was associated with greater absolute CHD risk reductions at high genetic risk (0.27%) versus low genetic risk (0.15%).

CONCLUSIONS

Replacing any amount of ST with an equal amount of MVPA time is associated with a lower relative risk of CHD, irrespective of genetic susceptibility to CHD. Reductions in CHD absolute risk for replacing ST with MVPA are greater at high genetic risk versus low genetic risk.

Device-measured physical activity and type 2 diabetes mellitus risk

Objectives

We investigated how device-measured physical activity (PA) volume (PA energy expenditure [PAEE]) and intensity (fraction of PAEE from moderate-to-vigorous PA [FMVPAEE]) were associated with the incidence of type 2 diabetes mellites (T2DM).

Methods

This population-based prospective cohort study included 90,044 participants. The primary exposures were PAEE and FMVPAEE. The secondary exposures were energy expenditure exerted during light, moderate, and vigorous PA and their fraction of PAEE.

Results

Each 1-SD increase in PAEE was associated with a 17% lower risk of T2DM (hazard ratio [HR]: 0.83, 95% confidence interval [CI]: 0.78-0.98). Each 1-SD increase in FMVPAEE was associated with a 21% lower incidence of T2DM (HR: 0.79, 95% CI: 0.74-0.83). Achieving the same PA volume (KJ/kg/day) through vigorous PA (HR: 0.88, 95% CI: 0.85-0.91) was more effective in preventing T2DM than moderate PA (HR: 0.97, 95% CI: 0.96-0.98) and light PA (HR: 0.99, 95% CI: 0.98-1.00).

Conclusion

A higher PA volume is associated with a lower incidence of T2DM. Achieving the same PA volumes through higher-intensity PA is more effective than low-intensity PA in reducing T2DM incidence.

BAYESIAN HIERARCHICAL MODELING AND ANALYSIS FOR ACTIGRAPH DATA FROM WEARABLE DEVICES

The majority of Americans fail to achieve recommended levels of physical activity, which leads to numerous preventable health problems such as diabetes, hypertension, and heart diseases. This has generated substantial interest in monitoring human activity to gear interventions toward environmental features that may relate to higher physical activity. Wearable devices, such as wrist-worn sensors that monitor gross motor activity (actigraph units) continuously record the activity levels of a subject, producing massive amounts of high-resolution measurements. Analyzing actigraph data needs to account for spatial and temporal information on trajectories or paths traversed by subjects wearing such devices. Inferential objectives include estimating a subject's physical activity levels along a given trajectory; identifying trajectories that are more likely to produce higher levels of physical activity for a given subject; and predicting expected levels of physical activity in any proposed new trajectory for a given set of health attributes. Here, we devise a Bayesian hierarchical modeling framework for spatial-temporal actigraphy data to deliver fully model-based inference on trajectories while accounting for subject-level health attributes and spatial-temporal dependencies. We undertake a comprehensive analysis of an original dataset from the Physical Activity through Sustainable Transport Approaches in Los Angeles (PASTA-LA) study to ascertain spatial zones and trajectories exhibiting significantly higher levels of physical activity while accounting for various sources of heterogeneity.

Association between questionnaire-based and accelerometer-based physical activity and the incidence of chronic kidney disease using data from UK Biobank: a prospective cohort study

Background

Prior studies on the relationship between chronic kidney disease (CKD) and physical activity (PA) mainly relied on subjective PA data and rarely considered the genetic risk. This study aims to thoroughly investigate this relationship by utilizing both accelerometer-measured and questionnaire-measured PA data.

Methods

This prospective cohort study encompasses two cohorts from the UK Biobank. The questionnaire-based cohort involves 448,444 CKD-free participants who completed an International Physical Activity Questionnaire between 2006 and 2010 and had genetic data. PA was categorized into distinct activities: leisure, housework, job-related, and transportation. The accelerometer-based cohort involves 89,296 CKD-free participants who provided a full week of accelerometer-based physical activity data between 2013 and 2015 and had genetic data. PA was classified as light-intensity, moderate-intensity, vigorous-intensity, moderate to vigorous-intensity PA (LPA, MPA, VPA, MVPA), and total PA. Incident CKD was ascertained from linked hospital inpatient and death records. Genetic risk was assessed using polygenic risk scores. Cox proportional hazard models with restricted cubic splines were used for the analysis.

Findings

In the questionnaire-based cohort, 18,184 (4.05%) participants developed CKD during 13.6 years of follow-up. Engaging in strenuous sports, other exercises, walking for pleasure, stair climbing, and heavy DIY were associated with a reduced risk of CKD. In the accelerometer-based cohort, 2297 (2.57%) participants developed CKD during 7.9 years of follow-up. Higher levels [highest quartile vs lowest quartile] of MPA (HR 0.639, 95% CI 0.554-0.737), VPA (HR 0.639, 95% CI 0.549-0.745), MVPA (HR 0.630, 95% CI 0.545-0.729), and total PA (HR 0.649, 95% CI 0.563-0.750) were associated with a lower CKD risk. There were significant interactions between MPA and genetic risk on the risk of CKD incidence (P for interaction = 0.025). A linear dose-response relationship was observed between MPA, total PA, and the risk of CKD incidence with no minimal or maximal threshold. These associations are robust in different subgroups and a series of sensitivity analyses.

Interpretation

Engaging in multiple types of PA and higher levels of total PA, MPA, VPA, and MVPA may be associated with a lower risk of developing CKD, regardless of genetic risk. This finding holds substantial implications for clinical approaches to CKD prevention and provides evidence to inform future PA guideline development.

Funding

Medical Science Advancement Program of Wuhan University, and the National Science Foundation of China.

Diet composition and energy intake in humans

Absolute energy from fats and carbohydrates and the proportion of carbohydrates in the food supply have increased over 50 years. Dietary energy density (ED) is primarily decreased by the water and increased by the fat content of foods. Protein, carbohydrates and fat exert different effects on satiety or energy intake (EI) in the order protein > carbohydrates > fat. When the ED of different foods is equalized the differences between fat and carbohydrates are modest. Covertly increasing dietary ED with fat, carbohydrate or mixed macronutrients elevates EI, producing weight gain and vice versa. In more naturalistic situations where learning cues are intact, there appears to be greater compensation for the different ED of foods. There is considerable individual variability in response. Macronutrient-specific negative feedback models of EI regulation have limited capacity to explain how availability of cheap, highly palatable, readily assimilated, energy-dense foods lead to obesity in modern environments. Neuropsychological constructs including food reward (liking, wanting and learning), reactive and reflective decision making, in the context of asymmetric energy balance regulation, give more comprehensive explanations of how environmental superabundance of foods containing mixtures of readily assimilated fats and carbohydrates and caloric beverages elevate EI through combined hedonic, affective, cognitive and physiological mechanisms. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.

Promotion of physical activity among people who identify as women through the ParticipACTION mobile app

OBJECTIVE

Health and fitness mobile applications can increase users' physical activity (PA) levels (Lister et al., 2014). ParticipACTION is a national non-profit organization that developed a mobile app to target PA among adults (Truelove et al., 2020). The aim of this research was to examine how women's PA is related to their use of the ParticipACTION app.

METHODS AND MEASUREMENT

Using a mixed-methods design, participants (n = 3,493) completed a survey regarding their PA levels, motivation for PA (capability, opportunity, motivation; COM-B, Keyworth et al., 2020), and motivation for using the ParticipACTION app. Nine focus groups were conducted (n = 37) to discuss the mobile app further.

RESULTS

Path analyses revealed that users' app use was positively associated with motivations for various app functions (e.g. self-monitoring, seeking exercise guidance), however, only motivation in-turn predicted PA. Descriptive results indicated that many women in Canada who used the app do not meet national guidelines for PA per week. Qualitative findings highlight women's motivation for using the app, concerns with app functionality, and feelings of guilt for not engaging in PA.

CONCLUSION

The ParticipACTION app may have some benefit for improving women's PA; intervention studies are needed to determine efficacy of mobile applications.

The Association of Physical Activity with Glaucoma and Related Traits in the UK Biobank

PURPOSE

To examine the association of physical activity (PA) with glaucoma and related traits, to assess whether genetic predisposition to glaucoma modified these associations, and to probe causal relationships using Mendelian randomization (MR).

DESIGN

Cross-sectional observational and gene-environment interaction analyses in the UK Biobank. Two-sample MR experiments using summary statistics from large genetic consortia.

PARTICIPANTS

UK Biobank participants with data on self-reported or accelerometer-derived PA and intraocular pressure (IOP; n = 94 206 and n = 27 777, respectively), macular inner retinal OCT measurements (n = 36 274 and n = 9991, respectively), and glaucoma status (n = 86 803 and n = 23 556, respectively).

METHODS

We evaluated multivariable-adjusted associations of self-reported (International Physical Activity Questionnaire) and accelerometer-derived PA with IOP and macular inner retinal OCT parameters using linear regression and with glaucoma status using logistic regression. For all outcomes, we examined gene-PA interactions using a polygenic risk score (PRS) that combined the effects of 2673 genetic variants associated with glaucoma.

MAIN OUTCOME MEASURES

Intraocular pressure, macular retinal nerve fiber layer (mRNFL) thickness, macular ganglion cell-inner plexiform layer (mGCIPL) thickness, and glaucoma status.

RESULTS

In multivariable-adjusted regression models, we found no association of PA level or time spent in PA with glaucoma status. Higher overall levels and greater time spent in higher levels of both self-reported and accelerometer-derived PA were associated positively with thicker mGCIPL (P < 0.001 for trend for each). Compared with the lowest quartile of PA, participants in the highest quartiles of accelerometer-derived moderate- and vigorous-intensity PA showed a thicker mGCIPL by +0.57 μm (P < 0.001) and +0.42 μm (P = 0.005). No association was found with mRNFL thickness. High overall level of self-reported PA was associated with a modestly higher IOP of +0.08 mmHg (P = 0.01), but this was not replicated in the accelerometry data. No associations were modified by a glaucoma PRS, and MR analyses did not support a causal relationship between PA and any glaucoma-related outcome.

CONCLUSIONS

Higher overall PA level and greater time spent in moderate and vigorous PA were not associated with glaucoma status but were associated with thicker mGCIPL. Associations with IOP were modest and inconsistent. Despite the well-documented acute reduction in IOP after PA, we found no evidence that high levels of habitual PA are associated with glaucoma status or IOP in the general population.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Energy expenditure and intensity of ritual jumping-dancing in male Maasai

OBJECTIVES

Traditional jumping-dance rituals performed by Maasai men involve prolonged physical exertion that may contribute significantly to overall physical activity level. We aimed to objectively quantify the metabolic intensity of jumping-dance activity and assess associations with habitual physical activity and cardiorespiratory fitness (CRF).

METHODS

Twenty Maasai men (18-37 years) from rural Tanzania volunteered to participate in the study. Habitual physical activity was monitored using combined heart rate (HR) and movement sensing over 3 days, and jumping-dance engagement was self-reported. A 1-h jumping-dance session resembling a traditional ritual was organized, during which participants' vertical acceleration and HR were monitored. An incremental, submaximal 8-min step test was performed to calibrate HR to physical activity energy expenditure (PAEE) and assess CRF.

RESULTS

Mean (range) habitual PAEE was 60 (37-116) kJ day-1  kg-1 , and CRF was 43 (32-54) mL O2  min-1  kg-1 . The jumping-dance activity was performed at an absolute HR of 122 (83-169) beats·min-1 , and PAEE of 283 (84-484) J min-1  kg-1 or 42 (18-75)% when expressed relative to CRF. The total PAEE for the session was 17 (range 5-29) kJ kg-1 , ~28% of the daily total. Self-reported engagement in habitual jumping-dance frequency was 3.8 (1-7) sessions/week, with a total duration of 2.1 (0.5-6.0) h/session.

CONCLUSIONS

Intensity during traditional jumping-dance activity was moderate, but on average sevenfold higher than habitual physical activity. These rituals are common, and can make a substantial contribution to overall physical activity in Maasai men, and thus be promoted as a culture-specific activity to increase energy expenditure and maintain good health in this population.

Causal associations between cardiorespiratory fitness and type 2 diabetes

Higher cardiorespiratory fitness is associated with lower risk of type 2 diabetes. However, the causality of this relationship and the biological mechanisms that underlie it are unclear. Here, we examine genetic determinants of cardiorespiratory fitness in 450k European-ancestry individuals in UK Biobank, by leveraging the genetic overlap between fitness measured by an exercise test and resting heart rate. We identified 160 fitness-associated loci which we validated in an independent cohort, the Fenland study. Gene-based analyses prioritised candidate genes, such as CACNA1C, SCN10A, MYH11 and MYH6, that are enriched in biological processes related to cardiac muscle development and muscle contractility. In a Mendelian Randomisation framework, we demonstrate that higher genetically predicted fitness is causally associated with lower risk of type 2 diabetes independent of adiposity. Integration with proteomic data identified N-terminal pro B-type natriuretic peptide, hepatocyte growth factor-like protein and sex hormone-binding globulin as potential mediators of this relationship. Collectively, our findings provide insights into the biological mechanisms underpinning cardiorespiratory fitness and highlight the importance of improving fitness for diabetes prevention.

Triaxial accelerometer-measured physical activity and functional behaviours among people with High Grade Glioma: The BrainWear Study

BACKGROUND

High-grade gliomas (HGG) account for 60-75% of all adult gliomas. The complexity of treatment, recovery and survivorship creates a need for novel monitoring approaches. Accurate assessment of physical function plays a vital role in clinical evaluation. Digital wearable tools could help us address unmet needs by offering unique advantages such as scale, cost and continuous real-world objective data. We present data from 42 patients enrolled into the BrainWear study.

METHODS

An AX3 accelerometer was worn by patients from diagnosis or at recurrence. Age-, sex-matched UK Biobank control groups were chosen for comparison.

RESULTS

80% of data were categorised as high-quality demonstrating acceptability. Remote, passive monitoring identifies moderate activity reduces both during a course of radiotherapy (69 to 16 minutes/day) and at the time of progressive disease assessed by MRI (72 to 52 minutes/day). Mean acceleration (mg) and time spent walking daily (h/day) correlated positively with the global health quality of life and physical functioning scores and inversely with the fatigue score. Healthy controls walked on average 2.91h/day compared to 1.32h/day for the HGG group on weekdays and 0.91h/day on the weekend. The HGG cohort slept for longer on weekends (11.6h/day) than weekdays (11.2h/day) compared to healthy controls (8.9h/day).

CONCLUSION

Wrist-worn accelerometers are acceptable and longitudinal studies feasible. HGG patients receiving a course of radiotherapy reduce their moderate activity by 4-fold and are at least half as active as healthy controls at baseline. Remote monitoring can provide a more informed and objective understanding of patient activity levels to help optimise health related quality of life (HRQoL) among a patient cohort with an extremely limited lifespan.

Comparison of wrist actimetry variables of paretic upper limb use in post stroke patients for ecological monitoring

BACKGROUND

To date, many wrist actimetric variables dedicated to measuring the upper limbs (UL) in post-stroke patients have been developed but very few comparisons have been made between them. The objective of this study was to compare different actimetric variables of the ULs between a stroke and healthy population.

METHODS

Accelerometers were worn continuously for a period of 7 days on both wrists of 19 post-stroke hemiparetic patients as well as 11 healthy subjects. Various wrist actimetry variables were calculated, including the Jerk ratio 50 (JR50, cumulative probability that the Jerk Ratio is between 1 and 2), absolute (FuncUse30) and relative (FuncUseRatio30) amounts of functional use of movements of the ULs with angular amplitude greater than 30°, and absolute (UH) and relative (UseHoursRatio) use hours.

RESULTS

FuncUse30, FuncUseRatio30, UH, UseHoursRatio and JR50 of the paretic UL of stroke patients were significantly lower than in the non-dominant UL of healthy subjects. Comparing the ratio variables in stroke patients, FuncUseRatio30 was significantly lower than UseHoursRatio and JR50, suggesting a more clinically sensitive variable to monitor. In an exploratory analysis, FuncUseRatio tends to decrease with angular range of motion for stroke patients while it remains stable and close to 1 for healthy subjects. UseHoursRatio, FuncUseRatio30 and JR50 show linear correlation with Fugl-Meyer score (FM), with r² equal to 0.53, 0.35 and 0.21, respectively.

CONCLUSION

This study determined that the FuncUseRatio30 variable provides the most sensitive clinical biomarker of paretic UL use in post-stroke patients, and that FuncUseHours-angular range of motion relationship allows the identification of the UL behaviour of each patient. This ecological information on the level of functional use of the paretic UL can be used to improve follow-up and develop patient-specific therapy.

Study protocol for two pilot randomised controlled trials aimed at increasing physical activity using electrically assisted bicycles to enhance prostate or breast cancer survival

BACKGROUND

In 2020, 1.4 and 2.3 million new cases of prostate cancer and breast cancer respectively were diagnosed globally. In the UK, prostate cancer is the most common male cancer, while breast cancer is the most common female cancer. Engaging in physical activity (PA) is a key component of treatment. However, rates of PA are low in these clinical populations. This paper describes the protocol of CRANK-P and CRANK-B, two pilot randomised controlled trials, involving an e-cycling intervention aimed at increasing PA in individuals with prostate cancer or breast cancer respectively.

METHODS

These two trials are single-centre, stratified, parallel-group, two-arm randomised waitlist-controlled pilot trials in which forty individuals with prostate cancer (CRANK-P) and forty individuals with breast cancer (CRANK-B) will be randomly assigned, in a 1:1 allocation ratio, to an e-cycling intervention or waitlist control. The intervention consists of e-bike training with a certified cycle instructor, followed by the provision of an e-bike for 12 weeks. Following the intervention period, participants in the e-bike condition will be directed to community-based initiatives through which they can access an e-bike. Data will be collected at baseline (T0), immediately post intervention (T1) and at 3-month follow-up (T2). In addition, in the intervention group, data will be collected during the intervention and follow-up periods. Quantitative and qualitative methods will be used. The primary objectives are to determine effective recruitment strategies, establish recruitment and consent rates, adherence and retention in the study, and determine the feasibility and acceptability of the study procedures and intervention. The potential impact of the intervention on clinical, physiological and behavioural outcomes will be assessed to examine intervention promise. Data analyses will be descriptive.

DISCUSSION

The findings from these trials will provide information on trial feasibility and highlight the potential of e-cycling as a strategy to positively impact the health and behaviour of individuals with prostate cancer and breast cancer. If appropriate, this information can be used to design and deliver a fully powered definitive trial.

TRIAL REGISTRATION

CRANK-B: [ISRCTN39112034]. CRANK-P [ISRCTN42852156]. Registered [08/04/2022] https://www.isrctn.com .

Wrist Accelerometer Estimates of Physical Activity Intensity During Walking in Older Adults and People Living With Complex Health Conditions: Retrospective Observational Data Analysis Study

BACKGROUND

Accurate measurement of daily physical activity (PA) is important as PA is linked to health outcomes in older adults and people living with complex health conditions. Wrist-worn accelerometers are widely used to estimate PA intensity, including walking, which composes much of daily PA. However, there is concern that wrist-derived PA data in these cohorts is unreliable due to slow gait speed, mobility aid use, disease-related symptoms that impact arm movement, and transient activities of daily living. Despite the potential for error in wrist-derived PA intensity estimates, their use has become ubiquitous in research and clinical application.

OBJECTIVE

The goals of this work were to (1) determine the accuracy of wrist-based estimates of PA intensity during known walking periods in older adults and people living with cerebrovascular disease (CVD) or neurodegenerative disease (NDD) and (2) explore factors that influence wrist-derived intensity estimates.

METHODS

A total of 35 older adults (n=23 with CVD or NDD) wore an accelerometer on the dominant wrist and ankle for 7 to 10 days of continuous monitoring. Stepping was detected using the ankle accelerometer. Analyses were restricted to gait bouts ≥60 seconds long with a cadence ≥80 steps per minute (LONG walks) to identify periods of purposeful, continuous walking likely to reflect moderate-intensity activity. Wrist accelerometer data were analyzed within LONG walks using 15-second epochs, and published intensity thresholds were applied to classify epochs as sedentary, light, or moderate-to-vigorous physical activity (MVPA). Participants were stratified into quartiles based on the percent of walking epochs classified as sedentary, and the data were examined for differences in behavioral or demographic traits between the top and bottom quartiles. A case series was performed to illustrate factors and behaviors that can affect wrist-derived intensity estimates during walking.

RESULTS

Participants averaged 107.7 (SD 55.8) LONG walks with a median cadence of 107.3 (SD 10.8) steps per minute. Across participants, wrist-derived intensity classification was 22.9% (SD 15.8) sedentary, 27.7% (SD 14.6) light, and 49.3% (SD 25.5) MVPA during LONG walks. All participants measured a statistically lower proportion of wrist-derived activity during LONG walks than expected (all P<.001), and 80% (n=28) of participants had at least 20 minutes of LONG walking time misclassified as sedentary based on wrist-derived intensity estimates. Participants in the highest quartile of wrist-derived sedentary classification during LONG walks were significantly older (t₁₆=4.24, P<.001) and had more variable wrist movement (t₁₆=2.13, P=.049) compared to those in the lowest quartile.

CONCLUSIONS

The current best practice wrist accelerometer method is prone to misclassifying activity intensity during walking in older adults and people living with complex health conditions. A multidevice approach may be warranted to advance methods for accurately assessing PA in these groups.

Comparison of different software for processing physical activity measurements with accelerometry

Several raw-data processing software for accelerometer-measured physical activity (PA) exist, but whether results agree has not been assessed. We examined the agreement between three different software for raw accelerometer data, and associated their results with cardiovascular risk. A cross-sectional analysis conducted between 2014 and 2017 in 2693 adults (53.4% female, 45-86 years) living in Lausanne, Switzerland was used. Participants wore the wrist-worn GENEActive accelerometer for 14 days. Data was processed with the GENEActiv manufacturer software, the Pampro package in Python and the GGIR package in R. For the latter, two sets of thresholds "White" and "MRC" defining levels of PA and two versions (1.5-9 and 1.11-1) for the "MRC" threshold were used. Cardiovascular risk was assessed using the SCORE risk score. Time spent (mins/day) in stationary, light, moderate and vigorous PA ranged from 633 (GGIR-MRC) to 1147 (Pampro); 93 (GGIR-White) to 196 (GGIR-MRC); 19 (GGIR-White) to 161 (GENEActiv) and 1 (GENEActiv) to 26 (Pampro), respectively. Spearman correlations between results ranged between 0.317 and 0.995, while concordance coefficients ranged between 0.035 and 0.968. With some exceptions, the line of perfect agreement was not in the 95% confidence interval of the Bland-Altman plots. Compliance to PA guidelines varied considerably: 99.8%, 98.7%, 76.3%, 72.6% and 50.2% for Pampro, GENEActiv, GGIR-MRC v.1.11-1, GGIR-MRC v.1.4-9 and GGIR-White, respectively. Cardiovascular risk decreased with increasing time spent in PA across most software packages. We found large differences in PA estimation between software and thresholds used, which makes comparability between studies challenging.

Effects of a family-based lifestyle intervention on co-physical activity and other health-related outcomes of fathers and their children: the 'Run Daddy Run' intervention

BACKGROUND

Fathers are important in establishing healthy behaviors in their children, but are rarely engaged in lifestyle programs. Focusing on physical activity (PA) of both fathers and their children by engaging them together in PA (i.e. "co-PA") is therefore a promising novel strategy for interventions. The study aim was to investigate the effect of the 'Run Daddy Run' on co-PA and PA of fathers and their children, and secondary outcomes such as weight status and sedentary behaviour (SB).

METHODS

This study is a non-randomized controlled trial (nRCT), including 98 fathers and one of their 6 to 8 years old children (intervention = 35, control = 63). The intervention was implemented over a 14-week period, and consisted of six (inter)active father-child sessions and an online component. Due to COVID-19, only 2/6 sessions could be implemented as planned, the remaining sessions were delivered online. In November 2019-January 2020 pre-test measurements took place, and post-test measurements in June 2020. Additional follow-up test was conducted in November 2020. PA (i.e. LPA, MPA, VPA and volume) of fathers and children were objectively measured using accelerometry, co-PA and the secondary outcomes were questioned using an online questionnaire.

RESULTS

Significant intervention effects were found for co-PA (+ 24 min./day in the intervention compared to the control group, p = 0.002), and MPA of the father (+ 17 min./day, p = 0.035). For children, a significant increase in LPA (+ 35 min./day, p < 0.001) was found. However, an inverse intervention effect was found for their MPA and VPA (-15 min./day, p = 0.005 and - 4 min./day, p = 0.002, respectively). Also decreases in fathers' and children's SB were found (-39 min./day, p = 0.022 and - 40 min./day, p = 0.003, respectively), but no changes in weight status, the father-child relationship, and the PA-family health climate (all p > 0.05).

CONCLUSION

The Run Daddy Run intervention was able to improve co-PA, MPA of fathers and LPA of children, and decreasing their SB. Inverse intervention effects were however found for MPA and VPA of children. These results are unique given their magnitude and clinical relevance. Targeting fathers together with their children might be a novel and potential intervention strategy to improve overall physical activity levels, however, further efforts should however be made to target children's MPA and VPA. Last, replicating these findings in a randomized controlled trial (RCT) is recommended for future research.

TRIAL REGISTRATION NUMBER

This study is registered as a clinical trial (clinicaltrials.gov, ID number: NCT04590755, date: 19/10/2020).

Physical activity volume, intensity, and incident cardiovascular disease

AIMS

The interplay between physical activity (PA) volume and intensity is poorly understood in relation to cardiovascular disease (CVD) risk. This study aimed to investigate the role of PA intensity, over and above volume, in relation to incident CVD.

METHODS AND RESULTS

Data were from 88 412 UK Biobank middle-aged adults (58% women) without prevalent CVD who wore accelerometers on their dominant wrist for 7 days, from which we estimated total PA energy expenditure (PAEE) using population-specific validation. Cox proportional hazards regressions modelled associations between PAEE (kJ/kg/day) and PA intensity (%MVPA; the fraction of PAEE accumulated from moderate-to-vigorous-intensity PA) with incident CVD (ischaemic heart disease or cerebrovascular disease), adjusted for potential confounders. There were 4068 CVD events during 584 568 person-years of follow-up (median 6.8 years). Higher PAEE and higher %MVPA (adjusted for PAEE) were associated with lower rates of incident CVD. In interaction analyses, CVD rates were 14% (95% confidence interval: 5-23%) lower when MVPA accounted for 20% rather than 10% of 15 kJ/kg/d PAEE; equivalent to converting a 14 min stroll into a brisk 7 min walk. CVD rates did not differ significantly between values of PAEE when the %MVPA was fixed at 10%. However, the lowest CVD rates were observed for combinations of both higher PAEE and %MVPA.

CONCLUSION

Reductions in CVD risk may be achievable through higher PA volume and intensity, with the role of moderately intense PA appearing particularly important. This supports multiple approaches or strategies to PA participation, some of which may be more practical or appealing to different individuals.

Longitudinal cardio-respiratory fitness prediction through wearables in free-living environments

Cardiorespiratory fitness is an established predictor of metabolic disease and mortality. Fitness is directly measured as maximal oxygen consumption (VO2max), or indirectly assessed using heart rate responses to standard exercise tests. However, such testing is costly and burdensome because it requires specialized equipment such as treadmills and oxygen masks, limiting its utility. Modern wearables capture dynamic real-world data which could improve fitness prediction. In this work, we design algorithms and models that convert raw wearable sensor data into cardiorespiratory fitness estimates. We validate these estimates' ability to capture fitness profiles in free-living conditions using the Fenland Study (N=11,059), along with its longitudinal cohort (N = 2675), and a third external cohort using the UK Biobank Validation Study (N = 181) who underwent maximal VO2max testing, the gold standard measurement of fitness. Our results show that the combination of wearables and other biomarkers as inputs to neural networks yields a strong correlation to ground truth in a holdout sample (r = 0.82, 95CI 0.80-0.83), outperforming other approaches and models and detects fitness change over time (e.g., after 7 years). We also show how the model's latent space can be used for fitness-aware patient subtyping paving the way to scalable interventions and personalized trial recruitment. These results demonstrate the value of wearables for fitness estimation that today can be measured only with laboratory tests.

Objective and Self-Reported Physical Activity and Risk of Falling Among Community-Dwelling Older Adults From Southern Brazil

This study evaluated prospective associations between self-reported and objectively measured physical activity (PA) and risk of falls among older adults. A cohort study started in 2014 with 1,451 community-dwelling older adults living in Pelotas, Brazil. Leisure-time PA was obtained by the International Physical Activity Questionnaire and 7-day raw accelerometer data evaluated for total, light PA, and moderate to vigorous PA. In 2016-2017, participants recorded their falls in the previous 12 months. Around 23% of the 1,161 participants followed-up in 2016-2017 experienced a fall in the last 12 months. Participants who did not spend any time in self-reported leisure-time PA at baseline had on average 34% higher risk of falls, and individuals in the lowest tertile for moderate to vigorous PA had on average 51% higher risk of falls compared to those in the highest tertile. Low levels of self-reported and objectively measured moderate to vigorous PA were related to higher risk of falling among Brazilian older adults.

Time spent in physical activity, sedentary behavior, and sleep: Associations with self-rated sleep quality in middle-aged and older adults

OBJECTIVES

We examined the associations of estimated allocations of time spent in physical activity, sedentary behavior and sleep with self-rated sleep quality.

METHODS

Between 2011 and 2016, 1918 participants (mean age 71 ± 9 years, 51% women) from the population-based Rotterdam Study were included. Durations of light physical activity, moderate-to-vigorous physical activity, sedentary behavior, and sleep were assessed by accelerometry, self-rated sleep quality with the Pittsburgh Sleep Quality Index. Associations were assessed with compositional isotemporal substitution analyses.

RESULTS

Spending 30 minutes more in sedentary behavior (adjusted mean difference in PSQI score: 0.21, 95% confidence interval [0.15; 0.28] or in light physical activity (adjusted mean difference in PSQI score: 0.25 [0.03; 0.46], and 30 minutes less in sleep, was associated with poorer sleep quality.

CONCLUSIONS

Our findings suggest reducing sedentary behavior and increasing sleep duration might be a potential intervention target to improve sleep quality in this population of middle-aged and older adults.

Historical development of accelerometry measures and methods for physical activity and sedentary behavior research worldwide: A scoping review of observational studies of adults

This scoping review identified observational studies of adults that utilized accelerometry to assess physical activity and sedentary behavior. Key elements on accelerometry data collection were abstracted to describe current practices and completeness of reporting. We searched three databases (PubMed, Web of Science, and SPORTDiscus) on June 1, 2021 for articles published up to that date. We included studies of non-institutionalized adults with an analytic sample size of at least 500. The search returned 5686 unique records. After reviewing 1027 full-text publications, we identified and abstracted accelerometry characteristics on 155 unique observational studies (154 cross-sectional/cohort studies and 1 case control study). The countries with the highest number of studies included the United States, the United Kingdom, and Japan. Fewer studies were identified from the continent of Africa. Five of these studies were distributed donor studies, where participants connected their devices to an application and voluntarily shared data with researchers. Data collection occurred between 1999 to 2019. Most studies used one accelerometer (94.2%), but 8 studies (5.2%) used 2 accelerometers and 1 study (0.6%) used 4 accelerometers. Accelerometers were more commonly worn on the hip (48.4%) as compared to the wrist (22.3%), thigh (5.4%), other locations (14.9%), or not reported (9.0%). Overall, 12.7% of the accelerometers collected raw accelerations and 44.6% were worn for 24 hours/day throughout the collection period. The review identified 155 observational studies of adults that collected accelerometry, utilizing a wide range of accelerometer data processing methods. Researchers inconsistently reported key aspects of the process from collection to analysis, which needs addressing to support accurate comparisons across studies.

Wearable accelerometer-derived physical activity and incident disease

Physical activity is regarded as favorable to health but effects across the spectrum of human disease are poorly quantified. In contrast to self-reported measures, wearable accelerometers can provide more precise and reproducible activity quantification. Using wrist-worn accelerometry data from the UK Biobank prospective cohort study, we test associations between moderate-to-vigorous physical activity (MVPA) – both total MVPA minutes and whether MVPA is above a guideline-based threshold of ≥150 min/week—and incidence of 697 diseases using Cox proportional hazards models adjusted for age, sex, body mass index, smoking, Townsend Deprivation Index, educational attainment, diet quality, alcohol use, blood pressure, anti-hypertensive use. We correct for multiplicity at a false discovery rate of 1%. We perform analogous testing using self-reported MVPA. Among 96,244 adults wearing accelerometers for one week (age 62 ± 8 years), MVPA is associated with 373 (54%) tested diseases over a median 6.3 years of follow-up. Greater MVPA is overwhelmingly associated with lower disease risk (98% of associations) with hazard ratios (HRs) ranging 0.70–0.98 per 150 min increase in weekly MVPA, and associations spanning all 16 disease categories tested. Overall, associations with lower disease risk are enriched for cardiac (16%), digestive (14%), endocrine/metabolic (10%), and respiratory conditions (8%) (chi-square p < 0.01). Similar patterns are observed using the guideline-based threshold of ≥150 MVPA min/week. Some of the strongest associations with guideline-adherent activity include lower risks of incident heart failure (HR 0.65, 95% CI 0.55–0.77), type 2 diabetes (HR 0.64, 95% CI 0.58–0.71), cholelithiasis (HR 0.61, 95% CI 0.54–0.70), and chronic bronchitis (HR 0.42, 95% CI 0.33–0.54). When assessed within 456,374 individuals providing self-reported MVPA, effect sizes for guideline-adherent activity are substantially smaller (e.g., heart failure HR 0.84, 95% CI 0.80–0.88). Greater wearable device-based physical activity is robustly associated with lower disease incidence. Future studies are warranted to identify potential mechanisms linking physical activity and disease, and assess whether optimization of measured activity can reduce disease risk.

Physical Activity Behaviors of a Middle-Age South African Cohort as Determined by Integrated Hip and Thigh Accelerometry

PURPOSE

Descriptive studies of objectively measured physical activity behaviors in African populations are rare. We developed a method of combining hip and thigh accelerometery signals to quantify and describe physical behaviors in middle-age South African men and women.

METHODS

We integrated signals from two triaxial accelerometers worn simultaneously during free-living, in a subsample of the Middle-age Soweto Cohort ( n = 794; mean (SD) age, 53.7 (6.3) yr). Acceleration time series from the accelerometers were combined and movement-related acceleration was derived using Euclidean Norm Minus One (in milligrams), to determine total movement volume (mean Euclidean Norm Minus One) and nonmovement time (<28 m g ), light-intensity physical activity (LPA; 28-85 m g ), and moderate- to vigorous-intensity physical activity (MVPA; >85 m g ); thigh pitch angle and a sleep diary were used to divide nonmovement time (in minutes per day) into sleep, awake sitting/lying, and standing. Sociodemographic factors were self-reported, and weight and height were measured.

RESULTS

Mean (SD) wear time was 128 (48) h. Movement volume was 15.0 (6.5) m g for men and 12.2 (3.4) m g for women. Men spent more time in MVPA and sitting/lying, whereas women spent more time standing. Age was inversely associated with movement volume, MVPA, and LPA. When compared with their normal-weight counterparts, men who were overweight or obese spent less time in MVPA, whereas women who were overweight or obese spent less time in LPA and more time sitting/lying. Socioeconomic status was inversely associated with total movement volume, MVPA, and time spent sleeping, and positively associated with time spent sitting/lying, in both men and women.

CONCLUSIONS

Integrating signals from hip and thigh accelerometers enables characterization of physical behaviors that can be applied in an African population.

Associations between abdominal adiposity, body size and objectively measured physical activity in infants from Soweto, South Africa

OBJECTIVES

Considering the importance of the early life period, in conjunction with the increasing prevalence of adiposity and insufficient physical activity already evident in early childhood, this study aimed to determine associations between abdominal adiposity, body size, and objectively measured physical activity in infancy.

METHODS

Infants (n = 138, aged 3-24 months) from Soweto, South Africa were recruited to this cross-sectional study. Visceral (VAT) and subcutaneous abdominal fat (SAT) were measured using ultrasound. Physical activity was assessed using accelerometry and analysed at the hourly level. Multilevel linear regression analyses were run with body composition exposures adjusted for age, sex, and length; models with VAT and SAT were also adjusted for total abdominal fat.

RESULTS

Mean (SD) age was 11.8 (7.6) months; 86% were normal weight, 7% were underweight and 7% overweight. In linear models, no body composition variable was significantly associated with physical activity. Physical activity was higher with each increasing length tertile (ANOVA p < 0.01); with a mean(95%CI) 29(60-60)mg in the lowest tertile, 39(71-71)mg in the middle tertile, and 50(81-82)mg in the highest tertile. Infants with normal weight had higher mean(95%CI) physical activity (40(70-80)mg) than underweight (34(73-85)mg, p = 0.01) or overweight infants (31(63-78)mg, ANOVA p < 0.01). When also adjusting for total abdominal fat, infants in the lowest SAT tertile had higher physical activity than those in the middle or highest SAT tertiles (p < 0.01).

CONCLUSIONS

These findings lend support for higher physical activity as a marker of healthy growth in the first two years of life.

Association between chronic pain and physical activity in a Swiss population-based cohort: a cross-sectional study

OBJECTIVE

To assess the bidirectional association between chronic pain and both subjectively and objectively measured physical activity (PA).

DESIGN

Cross-sectional study.

SETTING

Population-based sample in Lausanne, Switzerland, May 2014 to April 2017.

PARTICIPANTS

Non-stratified, representative sample of the population of Lausanne (Switzerland) aged 35-75 years. Participants were excluded if they had missing data for the pain or the PA questionnaires, for accelerometry (defined as >20% of non-wear time or duration <7 days) or for covariates.

PRIMARY OUTCOMES

Primary outcomes were association between chronic pain and previous, subjectively assessed PA (questionnaire), and subsequent, objectively assessed PA (accelerometry). Daily pain, pain duration, number of painful sites and pain intensity were assessed by questionnaire. PA was assessed by questionnaire 2 weeks prior and by accelerometry 2 weeks after completion of the pain questionnaire. PA was further categorised as sedentary (SED), light and moderate-to-vigorous PA.

RESULTS

2598 participants (52.9% women, mean age 60.5 years) had subjectively assessed PA. Multivariable analysis showed time spent in SED to be negatively associated with the number of painful sites: adjusted mean±SE 528±5, 522±7 and 502±7 min/day for 0, 1-2 and 3+ painful sites, respectively, p for trend <0.005. No other association was found between chronic pain and subjectively assessed PA categories. 2205 participants (52.8% women, mean age 61.7 years) had accelerometry-derived PA. No significant association between chronic pain and subsequent objectively assessed PA was found after multivariable analyses.

CONCLUSION

In this Swiss population-based cohort, no consistent association was found between chronic pain and PA. Hence, in the general population, chronic pain does not significantly impact time spent in PA.

Physical activity measured by accelerometry in paediatric and young adult patients with inflammatory bowel disease

OBJECTIVES

Physical activity in paediatric and young adult patients suffering from inflammatory bowel disease (IBD) may play an important role in the overall health status. However, physical activity in these patients has not been reported using objective methods. We aimed to describe accelerometry-measured physical activity levels in paediatric and young adult IBD patients with either ulcerative colitis (UC) or Crohn's disease (CD).

METHODS

We recruited Danish patients with IBD aged 10-20 years in clinical remission and with a faecal calprotectin below 200 µg/mg. Physical activity was assessed using tri-axial wrist accelerometry over seven days and quantified using the activity-related acceleration derived as the conventional Euclidian Norm Minus One (ENMO) metric expressed in milli-gravity units (mg). Time spent in Moderate-to-Vigorous Physical Activity (MVPA) was classified as ENMO > 210 mg in 5 s epoch resolution (unbouted).

RESULTS

We included 61 patients with a median age of 17 years [Inter Quartile Range, IQR 14-19]. The total volume of activity expressed as average acceleration (ENMO) per day was 31.5 mg (95% CI 29.1-33.9). Time spent in unbouted MVPA was 32 min per day (95% CI 26-37). There was no significant difference in activity volume between patients with UC to patients with CD, the adjusted linear regression coefficient was - 1.7 mg (95% CI -6.2-2.7). Activity volume was higher for males (36.2 mg, 95% CI 31.9-40.5) than for females (27.8 mg, 95% CI 25.6-30.0), and younger patients were more active than older patients; Activity volume in 10-13 year olds was 37.2 mg (95% CI 28.6-45.7), whereas it was 28.5 mg (95% CI 25.2-31.7) for those aged 18-20 years.

CONCLUSIONS

We collected tri-axial accelerometry in young patients with IBD in clinical remission, and described their level of physical activity by the conventional ENMO measure. We found no statistically significant difference in patients with UC compared to patients with CD. The volume of physical activity was higher in males compared to females, and inversely associated with age.

Objectively Measured Physical Activity Is Inversely Associated With Nonalcoholic Fatty Liver Disease: The Rotterdam Study

INTRODUCTION

The disease burden of nonalcoholic fatty liver disease (NAFLD) increases rapidly, in line with the obesity pandemic. Physical activity has been linked to a lower risk of NAFLD. However, the impact of different intensities of activity and sedentary behavior and whether their effects on NAFLD are explained by metabolic health remain unclear.

METHODS

We performed cross-sectional analyses within the population-based Rotterdam Study cohort. Abdominal ultrasound and accelerometry data were collected between 2009 and 2014. NAFLD was defined as hepatic steatosis diagnosed by ultrasound, in the absence of secondary causes for steatosis: viral hepatitis, steatogenic drugs, and excessive alcohol. We categorized accelerometry data into sedentary time and light, moderate, and vigorous physical activities.

RESULTS

We included 667 participants (aged 63.3 ± 6.3 years, 53% female individuals), and 34.3% had NAFLD. Total physical activity was associated with lower NAFLD prevalence adjusted for demographic, lifestyle, and socioeconomic factors (odds ratio: 0.958 per 10 min/d, 95% confidence interval [CI]: 0.929-0.986). More intensive physical activity was more strongly associated with lower NAFLD prevalence: odds ratios for light, moderate, and vigorous physical activities were 0.931 (95% CI: 0.882-0.982), 0.891 (95% CI: 0.820-0.967), and 0.740 (95% CI: 0.600-0.906) per 10 min/d, respectively. These associations were explained by metabolic health, particularly homeostatic model assessment of insulin resistance (proportion mediated: 0.59, P < 0.001) and waist circumference (proportion mediated: 1.08, P < 0.001). Beyond this indirect effect, no direct effect could be demonstrated (P = 0.282-0.827).

DISCUSSION

Physical activity at each intensity is inversely associated with NAFLD prevalence, with larger effects for higher intensities of physical activity. This association is mediated by better metabolic health, mainly lower insulin resistance and waist circumference. Physical activity should therefore be incorporated into NAFLD disease management and prevention programs.

Accelerometer-derived physical activity and risk of atrial fibrillation

AIMS

Physical activity may be an important modifiable risk factor for atrial fibrillation (AF), but associations have been variable and generally based on self-reported activity.

METHODS AND RESULTS

We analysed 93 669 participants of the UK Biobank prospective cohort study without prevalent AF who wore a wrist-based accelerometer for 1 week. We categorized whether measured activity met the standard recommendations of the European Society of Cardiology, American Heart Association, and World Health Organization [moderate-to-vigorous physical activity (MVPA) ≥150 min/week]. We tested associations between guideline-adherent activity and incident AF (primary) and stroke (secondary) using Cox proportional hazards models adjusted for age, sex, and each component of the Cohorts for Heart and Aging Research in Genomic Epidemiology AF (CHARGE-AF) risk score. We also assessed correlation between accelerometer-derived and self-reported activity. The mean age was 62 ± 8 years and 57% were women. Over a median of 5.2 years, 2338 incident AF events occurred. In multivariable adjusted models, guideline-adherent activity was associated with lower risks of AF [hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.75-0.89; incidence 3.5/1000 person-years, 95% CI 3.3-3.8 vs. 6.5/1000 person-years, 95% CI 6.1-6.8] and stroke (HR 0.76, 95% CI 0.64-0.90; incidence 1.0/1000 person-years, 95% CI 0.9-1.1 vs. 1.8/1000 person-years, 95% CI 1.6-2.0). Correlation between accelerometer-derived and self-reported MVPA was weak (Spearman r = 0.16, 95% CI 0.16-0.17). Self-reported activity was not associated with incident AF or stroke.

CONCLUSIONS

Greater accelerometer-derived physical activity is associated with lower risks of AF and stroke. Future preventive efforts to reduce AF risk may be most effective when targeting adherence to objective activity thresholds.

Substitutions of physical activity, sedentary behaviour and sleep: associations with mental health in middle-aged and elderly persons

Background

Physical activity, sedentary behaviour and sleep are potential risk factors of mental health disorders, but previous studies have not considered the dependency between these activity domains. Therefore, we examined the associations of reallocations of time among older adults’ physical activity, sedentary behaviour and sleep with depressive and anxiety symptoms using compositional isotemporal substitution analyses.

Methods

We included 1943 participants (mean age 71 years, SD: 9; 52% women) from the population-based Rotterdam Study. Between 2011 and 2016, we collected accelerometer data (mean duration 5.8 days, SD: 0.4) on physical activity, sedentary behaviour and sleep and self-reported data on depressive symptoms and anxiety.

Results

A reallocation of 30 min more moderate-to-vigorous physical activity was associated with a −0.55 (95% CI −1.04 to −0.06) points lower depressive symptoms score when replacing sleep and a −0.59 (95% CI −1.06 to −0.12) points lower score when replacing sedentary behaviour, but not when replacing light physical activity (−0.70, 95% CI −1.63 to 0.24). No associations were found for anxiety.

Conclusion

Replacing sedentary behaviour or sleep with more moderate-to-vigorous physical activity was associated with less depressive symptoms, suggesting that mainly intensive types of physical activity are important for middle-aged and older adults in relation to depressive symptoms.

Assessment of Physical Activity in Adults using Wrist Accelerometers

The health benefits of physical activity have been widely recognized, yet traditional measures of physical activity including questionnaires and category-based assessments of volume and intensity provide only broad estimates of daily activities. Accelerometers have advanced epidemiologic research on physical activity by providing objective and continuous measurement of physical activity in free-living conditions. Wrist-worn accelerometers have become especially popular due to low participant burden. However, the validity and reliability of wrist-worn devices for adults have yet to be summarized. Moreover, accelerometer data provide rich information on how physical activity is accumulated throughout the day, but only a small portion of these rich data have been utilized by researchers. Lastly, new methodological developments that aim to overcome some of the limitations of accelerometers are emerging. The purpose of this review is to provide an overview of accelerometry research, with a special focus on wrist-worn accelerometers. We describe briefly how accelerometers work, summarize the validity and reliability of wrist-worn accelerometers, discuss the benefits of accelerometers including measuring light-intensity physical activity, and discuss pattern metrics of daily physical activity recently introduced in the literature. A summary of large-scale cohort studies and randomized trials that implemented wrist-worn accelerometry is provided. We conclude the review by discussing new developments and future directions of research using accelerometers, with a focus on wrist-worn accelerometers.

Stress, physical activity, sedentary behavior, and resilience-The effects of naturalistic periods of elevated stress: A measurement-burst study

Stress is an important consideration for understanding why individuals take part in limited or no physical activity. The negative effects of stress on physical activity do not hold for everyone, so examinations of possible resilience resources that might protect individuals from the harmful effects of stress are required. Accordingly, we conducted a measurement-burst study with 53 university students over a 6-month period to examine the dynamics among stress, physical activity, sedentary behavior, and resilience resources. Participants completed three bursts of 6 days, with each burst separated by an 8-week gap. Expectations regarding the moderating effects of resilience resources were unsupported. Daily reports of academic and general stress were positively associated with sedentary behavior and negatively associated with light and moderate intensity physical activity. Hair cortisol concentration significantly moderated the association between academic stress and sedentary behavior, such that in bursts where cortisol was lower the daily positive association between stress and sedentary behavior was weaker. The finding that academic and general stress are dynamically associated with lower levels of light and moderate intensity physical activity and higher levels of sedentary behavior is an important extension to previous research, which has relied mainly on cross-sectional designs and self-report methods. Future research might examine resilience resources that are specific to the outcomes of interest rather than rely on generic resources.

Clinical and demographic correlates of accelerometer-measured physical activity in participants enrolled in the OPTIMISE HFpEF study

AIMS

This study aimed to measure physical activity (PA) in participants with suspected heart failure with preserved ejection fraction (HFpEF) and assess associations between PA and participant characteristics.

METHODS AND RESULTS

Adults with presumed HFpEF were recruited and received diagnostic evaluation and clinical assessment. Physical activity was objectively measured using accelerometers over 7 days. To examine predictors of PA, a best subset analysis was used, with the optimal model defined as that with the lowest Bayesian information criterion. One hundred and twenty-four participants with presumed HFpEF who had valid accelerometer data were included in this study. Seventy-six were confirmed by a cardiologist as meeting the European Society of Cardiology diagnosis criteria for HFpEF. The median age of all participants was 80.1 years, and 47.4% were female. Patients spent most of each 24-h period at low-intensity PA and few or no durations at high-intensity PA, with lower activity for those with HFpEF. Gait speed was the best univariate correlate of activity levels (adjusted R2 0.29). The optimal model using best subsets regression included six variables and improved adjusted R2 to 0.47. In the model, lower levels of PA were associated with slower gait speed, lower levels of anxiety, higher levels of depression, past smoking history, a confirmed HFpEF diagnosis, and higher body mass index.

CONCLUSION

Participants demonstrated very low PA levels. The study has identified important patient characteristics associated with PA, which may help to identify those most in need of interventions. Notably, participants with confirmed HFpEF were more inactive than participants with other heart failure phenotypes.

A school-based, peer-led programme to increase physical activity among 13- to 14-year-old adolescents: the GoActive cluster RCT

Background

Adolescent physical activity levels are low and are associated with rising disease risk and social disadvantage. The Get Others Active (GoActive) intervention was co-designed with adolescents and teachers to increase physical activity in adolescents.

Objective

To assess the effectiveness and cost-effectiveness of the school-based GoActive programme in increasing adolescents’ moderate-to-vigorous physical activity.

Design

A cluster randomised controlled trial with an embedded mixed-methods process evaluation.

Setting

Non-fee-paying schools in Cambridgeshire and Essex, UK (n = 16). Schools were computer randomised and stratified by socioeconomic position and county.

Participants

A total of 2862 Year 9 students (aged 13–14 years; 84% of eligible students).

Intervention

The iteratively developed feasibility-tested refined 12-week intervention trained older adolescents (mentors) and in-class peer leaders to encourage classes to undertake two new weekly activities. Mentors met with classes weekly. Students and classes gained points and rewards for activity in and out of school.

Main outcome measures

The primary outcome was average daily minutes of accelerometer-assessed moderate-to-vigorous physical activity at 10 months post intervention. Secondary outcomes included accelerometer-assessed activity during school, after school and at weekends; self-reported physical activity and psychosocial outcomes; cost-effectiveness; well-being and a mixed-methods process evaluation. Measurement staff were blinded to allocation.

Results

Of 2862 recruited participants, 2167 (76%) attended 10-month follow-up measurements and we analysed the primary outcome for 1874 (65.5%) participants. At 10 months, there was a mean decrease in moderate-to-vigorous physical activity of 8.3 (standard deviation 19.3) minutes in control participants and 10.4 (standard deviation 22.7) minutes in intervention participants (baseline-adjusted difference –1.91 minutes, 95% confidence interval –5.53 to 1.70 minutes; p = 0.316). The programme cost £13 per student compared with control. Therefore, it was not cost-effective. Non-significant indications of differential impacts suggested detrimental effects among boys (boys –3.44, 95% confidence interval –7.42 to 0.54; girls –0.20, 95% confidence interval –3.56 to 3.16), but favoured adolescents from lower socioeconomic backgrounds (medium/low 4.25, 95% confidence interval –0.66 to 9.16; high –2.72, 95% confidence interval –6.33 to 0.89). Mediation analysis did not support the use of any included intervention components to increase physical activity. Some may have potential for improving well-being. Students, teachers and mentors mostly reported enjoying the GoActive intervention (56%, 87% and 50%, respectively), but struggled to conceptualise their roles. Facilitators of implementation included school support, embedding a routine, and mentor and tutor support. Challenges to implementation included having limited school space for activities, time, and uncertainty of teacher and mentor roles.

Limitations

Retention on the primary outcome at 10-month follow-up was low (65.5%), but we achieved our intended sample size, with retention comparable to similar trials.

Conclusions

A rigorously developed school-based intervention (i.e. GoActive) was not effective in countering the age-related decline in adolescent physical activity. Overall, this mixed-methods evaluation provides transferable insights for future intervention development, implementation and evaluation.

Future work

Interdisciplinary research is required to understand educational setting-specific implementation challenges. School leaders and authorities should be realistic about expectations of the effect of school-based physical activity promotion strategies implemented at scale.

Trial registration

Current Controlled Trials ISRCTN31583496.

Funding

This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 9, No. 6. See the NIHR Journals Library website for further project information. This work was additionally supported by the Medical Research Council (London, UK) (Unit Programme number MC_UU_12015/7) and undertaken under the auspices of the Centre for Diet and Activity Research (Cambridge, UK), a UK Clinical Research Collaboration Public Health Research Centre of Excellence. Funding from the British Heart Foundation (London, UK), Cancer Research UK (London, UK), Economic and Social Research Council (Swindon, UK), Medical Research Council, the National Institute for Health Research (Southampton, UK) and the Wellcome Trust (London, UK), under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged (087636/Z/08/Z; ES/G007462/1; MR/K023187/1). GoActive facilitator costs were borne by Essex and Cambridgeshire County Councils.

Measurement of Physical Activity by Shoe-Based Accelerometers-Calibration and Free-Living Validation

There is conflicting evidence regarding the health implications of high occupational physical activity (PA). Shoe-based accelerometers could provide a feasible solution for PA measurement in workplace settings. This study aimed to develop calibration models for estimation of energy expenditure (EE) from shoe-based accelerometers, validate the performance in a workplace setting and compare it to the most commonly used accelerometer positions. Models for EE estimation were calibrated in a laboratory setting for the shoe, hip, thigh and wrist worn accelerometers. These models were validated in a free-living workplace setting. Furthermore, additional models were developed from free-living data. All sensor positions performed well in the laboratory setting. When the calibration models derived from laboratory data were validated in free living, the shoe, hip and thigh sensors displayed higher correlation, but lower agreement, with measured EE compared to the wrist sensor. Using free-living data for calibration improved the agreement of the shoe, hip and thigh sensors. This study suggests that the performance of a shoe-based accelerometer is similar to the most commonly used sensor positions with regard to PA measurement. Furthermore, it highlights limitations in using the relationship between accelerometer output and EE from a laboratory setting to estimate EE in a free-living setting.

Genetically predicted physical activity levels are associated with lower colorectal cancer risk: a Mendelian randomisation study

BACKGROUND

We conducted a Mendelian randomisation (MR) study to investigate whether physical activity (PA) causes a reduction of colorectal cancer risk and to understand the contributions of effects mediated through changes in body fat.

METHODS

Common genetic variants associated with self-reported moderate-to-vigorous PA (MVPA), acceleration vector magnitude PA (AMPA) and sedentary time were used as instrumental variables. To control for confounding effects of obesity, we included instrumental variables for body mass index (BMI), body fat percentage, waist circumference and arm, trunk and leg fat ratios. We analysed the effect of these instrumental variables in a colorectal cancer genome-wide association study comprising 31,197 cases and 61,770 controls of European ancestry by applying two-sample and multivariable MR study designs.

RESULTS

We found decreased colorectal cancer risk for genetically represented measures of MVPA and AMPA that were additional to effects mediated through genetic measures of obesity. Odds ratio and 95% confidence interval (CI) per standard deviation increase in MVPA and AMPA was 0.56 (0.31, 1.01) and 0.60 (0.41, 0.88), respectively. No association has been found between sedentary time and colorectal cancer risk. The proportion of effect mediated through BMI was 2% (95% CI: 0, 14) and 32% (95% CI: 12, 46) for MVPA and AMPA, respectively.

CONCLUSION

These findings provide strong evidence to reinforce public health measures on preventing colorectal cancer that promote PA at a population level regardless of body fatness.

Current Evidence of Measurement Properties of Physical Activity Questionnaires for Older Adults: An Updated Systematic Review

BACKGROUND

Questionnaires provide valuable information about physical activity (PA) behaviors in older adults. Until now, no firm recommendations for the most qualified questionnaires for older adults have been provided.

OBJECTIVES

This review is an update of a previous systematic review, published in 2010, and aims to summarize, appraise and compare the measurement properties of all available self-administered questionnaires assessing PA in older adults.

METHODS

We included the articles evaluated in the previous review and conducted a new search in PubMed, Embase, and SPORTDiscus from September 2008 to December 2019, using the following inclusion criteria (1) the purpose of the study was to evaluate at least one measurement property (reliability, measurement error, hypothesis testing for construct validity, responsiveness) of a self-administered questionnaire; (2) the questionnaire intended to measure PA; (3) the questionnaire covered at least one domain of PA; (4) the study was performed in the general, healthy population of older adults; (5) the mean age of the study population was > 55 years; and (6) the article was published in English. Based on the Quality Assessment of Physical Activity Questionnaires (QAPAQ) checklist, we evaluated the quality and results of the studies. The content validity of all included questionnaires was also evaluated using the reviewers' rating. The quality of the body of evidence was evaluated for the overall construct of each questionnaire (e.g., total PA), moderate-to-vigorous physical activity (MVPA) and walking using a modified Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

In total, 56 articles on 40 different questionnaires (14 from the previous review and 26 from the update) were included. Reliability was assessed for 22, measurement error for four and hypotheses testing for construct validity for 38 different questionnaires. Evidence for responsiveness was available for one questionnaire. For many questionnaires, only one measurement property was assessed in only a single study. Sufficient content validity was considered for 22 questionnaires. All questionnaires displayed large measurement errors. Only versions of two questionnaires showed both sufficient reliability and hypotheses testing for construct validity, namely the Physical Activity Scale for the Elderly (PASE; English version, Turkish version) for the assessment of total PA, and the Physical Activity and Sedentary Behavior Questionnaire (PASB-Q; English version) for the assessment of MVPA. The quality of evidence for these results ranged from very low to high.

CONCLUSIONS

Until more high-quality evidence is available, we recommend the PASE for measuring total PA and the PASB-Q for measuring MVPA in older adults. However, they are not equally qualified among different languages. Future studies on the most promising questionnaires should cover all relevant measurement properties. We recommend using and improving existing PA questionnaires-instead of developing new ones-and considering the strengths and weaknesses of each PA measurement instrument for a particular purpose.