Practical considerations in using accelerometers to assess physical activity, sedentary behavior, and sleep

On-time power mobility and physical activity in toddlers with motor delays: A randomized controlled trial using body-worn sensors

This study conducted a secondary analysis to objectively measure the effects of modified ride-on cars (MROCs) training in different postures on physical activity (PA) levels in children with motor delays. Data from 39 participants were analyzed in a randomized controlled trial. The participants included those using MROC in standing postures (n = 11, mean age = 22.87 months), MROC in sitting postures (n = 16, mean age = 19.53 months), and a control group that received conventional therapy (n = 12, mean age = 23.30 months). PA intensity was measured using an ActiGraph GT3X on the participants' wrists and right hip at weeks 1, 6, and 12 of the 12-week intervention period. This trial was registered at ClinicalTrials.gov (NCT02527356). The demographic data were similar across the groups. No significant differences were found in the interaction, group, or time effects for any of the positions (p > 0.05). The PA levels were consistent in at least light PA intensity range. MROC training may yield PA levels comparable to those of conventional therapy. Variations in activity and motor impairment severity could affect outcomes. Future studies should investigate factors such as task characteristics, motor delay severity, PA cutoff points, and training dosage that may influence PA intensity.

Early Gait Biomechanics Linked to Daily Steps After Anterior Cruciate Ligament Reconstruction

CONTEXT

Gait biomechanics and daily steps are important aspects of knee-joint loading that change after anterior cruciate ligament reconstruction (ACLR). Understanding their relationship during the first 6 months post-ACLR could help clinicians develop comprehensive rehabilitation interventions that promote optimal joint loading after injury, thereby improving long-term knee-joint health.

OBJECTIVES

To compare biomechanical gait waveforms throughout stance at early time points post-ACLR in individuals with different daily step behaviors at 6 months post-ACLR and to examine how these gait waveforms compare with those of uninjured controls.

DESIGN

Case-control study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 32 individuals with primary ACLR assigned to the low-step group (LSG; n = 13) or the high-step group (HSG; n = 19) based on their average daily steps at 6 months post-ACLR and 32 uninjured matched controls.

MAIN OUTCOME MEASURE(S)

Gait biomechanics were collected at 2, 4, and 6 months post-ACLR for the ACLR groups and at a single session for the control group. Knee-adduction moment, knee-extension moment (KEM), and knee-flexion angle (KFA) waveforms were calculated during gait stance and then compared via functional waveform analyses. Mean differences and corresponding 95% CIs between groups were reported.

RESULTS

Primary results demonstrated less KFA (1%-45% versus 79%-92% of stance) and greater KEM (65%-93% of stance) at 2 months and greater knee-adduction moment (14%-20% versus 68%-92% of stance) at 4 months post-ACLR for the HSG compared with the LSG. Knee-adduction moment, KEM, and KFA waveforms differed across various proportions of stance at all time points between the step and control groups.

CONCLUSIONS

Differences in gait biomechanics were present at 2 and 4 months post-ACLR between step groups, with the LSG demonstrating an overall more flexed knee and more profound stepwise underloading throughout stance than the HSG. The results indicate a relation between early gait biomechanics and later daily step behaviors post-ACLR.

Accelerometry-assessed sleep clusters and obesity in adolescents and young adults: a longitudinal analysis in GINIplus/LISA birth cohorts

BACKGROUND

Some studies have revealed various sleep patterns in adolescents and adults using multidimensional objective sleep parameters. However, it remains unknown whether these patterns are consistent from adolescence to young adulthood and how they relate to long-term obesity.

METHODS

Seven-day accelerometry was conducted in German Infant Study on the influence of Nutrition Intervention PLUS environmental and genetic influences on allergy development (GINIplus) and Influence of Lifestyle factors on the development of the Immune System and Allergies in East and West Germany (LISA) birth cohorts during the 15-year and 20-year follow-ups, respectively. Five sleep clusters were identified by k-means cluster analysis using 12 sleep characteristics at each follow-up. Adjusted linear and logistic regression models using generalized estimating equations were examined. Further, the interaction effects with time of follow-ups and polygenic risk scores (PRS) for body mass index (BMI) were tested.

RESULTS

Five sleep clusters were classified consistently in both adolescence (n = 1347, aged 14.3-16.4 years) and young adulthood (n = 1262, aged 19.5-22.4 years). Adolescents in the "good sleep", "delayed sleep phase", and "fragmented sleep" clusters displayed greater stability transitioning into young adulthood, while those in the "sleep irregularity and variability", and "prolonged sleep latency" clusters showed lower stability (n = 636). Compared to the "good sleep" cluster, the "prolonged sleep latency" cluster exhibited associations with higher BMI [β = 0.56, 95% confidence interval (CI) = (0.06, 1.05)] and increased odds of overweight/obesity [Odds ratio = 1.55, 95% CI = (1.02, 2.34)]. No significant PRS-sleep cluster interaction was found for BMI or overweight/obesity. Among males only, the "delayed sleep phase", "sleep irregularity and variability" and "fragmented sleep" clusters showed stronger associations with overweight/obesity as age increased.

CONCLUSION

Adolescents and young adults shared five consistent sleep patterns, with the "prolonged sleep latency" pattern linked to higher BMI and overweight/obesity.

Out-of-school Activities and Adherence to 24-hour Movement Guidelines

INTRODUCTION

The purpose of this study was to explore associations between participation in out-of-school/weekend organized activities and adherence to the 24-hour movement guidelines among US adolescents.

METHODS

Data from the 2022 National Survey of Children's Health (N=16,403, age=15.1±1.4 years, 48.1% female) was used for analyses in 2024. A parent/guardian completed surveys regarding adolescents' 24-hour movement behaviors (physical activity [PA], sleep [SL], and screentime [ST]), as well as participation in out-of-school and weekend activities (sports, clubs, other organized activities, and volunteering). Weighted logistic regression models were used to examine associations between participation in out-of-school and weekend organized activities and 24-hour movement guideline adherence, adjusted for sex, age, race/ethnicity, federal poverty level status, metropolitan statistical area status, and overweight/obesity status.

RESULTS

Only 4.8% of adolescents met all three guidelines concurrently. Adolescents who participated in sports teams/lessons had higher odds of meeting PA (OR=2.11, 95% CI: 1.67-2.66), ST (OR=1.31, 95% CI: 1.12-1.53), PA+ST (OR=2.24, 95% CI: 1.63-3.07), PA+SL (OR=2.00, 95% CI: 1.53-2.63), SL+ST (OR=1.40, 95% CI; 1.19-1.66), and all three guidelines (OR=2.33, 95% CI: 1.61-3.39). Participation in other organized activities/lessons was associated with higher odds of meeting ST (OR=1.32, 95% CI: 1.13-1.56), and SL+ST guidelines (OR=1.39, 95% CI: 1.16-1.66). Adolescents who volunteered had higher odds of meeting ST (OR=1.68, 95% CI: 1.42-1.98), PA+ST (OR=1.75, 95% CI: 1.25-2.45), SL+ST (OR=1.64, 95% CI: 1.38-1.95), and all three guidelines (OR=1.80, 95% CI: 1.20-2.72).

CONCLUSIONS

Participating in sports teams/lessons and community service/volunteer work is beneficially associated with concurrently meeting all three 24-hour movement guidelines and participating in other organized activities or lessons is associated with adherence to individual components of the 24-hour movement guidelines among US adolescents.

Assessing the longitudinal association between sleep, diet quality and BMI z-score among Black adolescent girls

BACKGROUND

Cross-sectional research has suggested associations between diet, sleep and obesity, with sparse longitudinal research.

OBJECTIVES

To identify longitudinal mechanistic associations between sleep, diet and obesity.

METHODS

We used longitudinal data from a sample of Black adolescent girls. At T1 (enrolment), 6 months (T2) and 18 months (T3), we estimated sleep duration and quality (7-day accelerometry), diet quality (Healthy Eating Index [HEI-2020]) and body mass z-scores (zBMI) from measured height and weight. Longitudinal mediation using structural equation models examined the mechanistic roles of sleep, diet quality and zBMI.

RESULTS

At enrolment, girls (n = 441) were mean age 12.2 years (±0.71), 48.3% had overweight/obesity, and mean HEI 55.8 (±7.49). The association between sleep and diet quality did not vary over time. Sleep duration at T1 was not associated with diet quality at T2 nor was diet associated with zBMI at T3. The bootstrapped indirect effect was not significant. Sleep quality at T1 was not associated with diet quality at T2 nor was diet associated with zBMI at T3. The bootstrapped indirect effect was not significant.

CONCLUSIONS

Diet was not a mediator between sleep and obesity. Study strengths are the longitudinal design and direct measures of sleep and zBMI among a homogeneous sample.

Objectively-Measured Sedentary Time and Self-Reported Prescription Medication Use Among Adults: A Pilot Study

While previous research has linked physical activity (PA) with lower prescription medication consumption, limited evidence has investigated sedentary time (ST) as a major contributor to medication use, despite ST's known association with chronic disease and mortality risk, even when PA volume is considered. This study aimed to examine the independent associations between objectively measured ST, patterns of sedentary bouts, and self-reported prescription medication use among adults ≥25 years of age. Thirty-two participants reported the number and type of medications they were currently prescribed and wore an accelerometer continuously on their hip for seven days to detect their ST. Poisson regression analysis was used to assess how average daily ST, sedentary bout frequency, and sedentary bout duration influenced medication use. The results revealed a significant association between greater ST and higher medication consumption. Specifically, each additional hour of ST per day, each sedentary bout, and each one-minute increase in bout duration were linked to a 66% (PR 1.66; 95% CI 1.25-2.19; p < 0.001), 36% (PR 1.36; 95% CI 1.12-1.64; p < 0.01), and 9% (PR 1.09; 95% CI 1.03-1.16; p < 0.01) higher prevalence of prescription medications, respectively. These findings suggest that higher ST is associated with a greater prevalence of using prescription medications in adults.

Association of daily physical activity and bone microarchitecture in young adults with type 1 diabetes - A pilot exploratory study

Purpose

Physical activity (PA) is an important determinant of skeletal health. In young adults with type 1 diabetes (T1D) fracture risk is increased, yet few studies have examined the PA and bone health relationship. Therefore, this pilot cross-sectional study characterized PA levels and their association with bone parameters measured by high resolution peripheral quantitative computed tomography (HR-pQCT) in young adults with T1D.

Methods

HR-pQCT (Xtreme CTII) was used to measure bone outcomes at the distal tibia and radius, and accelerometery (ActiGraph GT3X) recorded daily minutes of light and moderate-vigorous physical activity (MVPA). Quadratic regression analyses were conducted with a p-value ≤ 0.05 considered significant.

Results

PA data from 19 young adults (23.1 ± 1.9 years) with T1D was analyzed. Over half (63 %) of participants completed ≥150 min of MVPA per week, however, most measured activity time per day (57 %) was spent in sedentary pursuits. Significant non-linear associations were found between the duration of MVPA and several trabecular bone parameters at the tibia.

Conclusions

In young adults with T1D, MVPA may have site specific (tibia) and compartment specific (trabecular) non-linear associations with bone. Further studies should confirm these findings, which may help inform evidence-based exercise recommendations to optimize bone health in young adults with T1D.

Effects of physical activity planning interventions on reducing sedentary behavior in parent-child dyads: A randomized controlled trial

Effects of parent-child dyad interventions on behavior remain unclear. This randomized controlled trial investigated if, compared with a control condition, three types of physical activity (PA) planning interventions (individual "I-for-me," dyadic "we-for-me," and collaborative "we-for-us") would reduce sedentary behavior (SB) time in parents and their children. The study involved 247 dyads comprising parents (aged 29-66) and their children (aged 9-15), randomized into one of the three types of PA planning-intervention arms or the control condition. Mixed models were applied to analyze data from a preregistered trial (NCT02713438) with the outcome of accelerometer-measured SB time, assessed at 1-week and 36-week follow-ups. Although children's SB remained unaffected by the planning interventions, a small reduction of SB time was found among parents in the collaborative (p = .048) and individual (p = .042) planning conditions. The effects were observed at the 1-week follow-up only. While short-term reductions in parents' SB were achieved, these were not sustained long-term. PA planning interventions delivered to parent-child dyads did not substantially reduce children's SB, which may be due to young people's needs of increased independence from their parents.

The Cross-Sectional and Longitudinal Associations Between Adherence to 24-Hour Movement Behavior Guidelines and Bone Health in Young Children

BACKGROUND

Adherence to the World Health Organization's 24-hour movement behavior (24-HMB) guidelines is associated with various health outcomes. However, its relationship with bone mineral density (BMD) in young children has not been investigated. This study aimed to examine the cross-sectional and longitudinal associations between adherence to the 24-HMB guidelines and BMD in young children.

METHODS

A total of 120 children aged 3-5 years were recruited from three kindergartens in Changsha, Hunan, China. Physical activity (PA) was objectively measured using ActiGraph wGT3X-BT accelerometers, and BMD was assessed using the Sunlight Omnisense 7000P ultrasound device. Screen time (ST) and sleep duration (SD) were reported by parents. Logistic regression was used to analyze the associations between guideline adherence and BMD.

RESULTS

Only 5.5% of the participants met all three guidelines for PA, ST, and SD, while 16.5% did not meet any. In the cross-sectional analysis, young children who met both ST and SD guidelines (OR = 0.29, 95% CI: 0.09, 0.95) had a lower risk of insufficient BMD compared to those who met none. In the one-year cohort follow-up, young children who met the PA guideline at baseline (OR = 0.22, 95% CI: 0.07, 0.71), as well as those who met both the PA and ST guidelines (OR = 0.18, 95% CI: 0.04, 0.83) or all three (OR = 0.13, 95% CI: 0.03, 0.69), had a lower risk of insufficient BMD at one year.

CONCLUSIONS

Adherence to the 24-HMB guidelines may promote bone health in young children. Future research should prioritize achievable goals, such as limiting ST and ensuring adequate SD, while gradually increasing MVPA to optimize bone development.

Telehealth based parental support over 6 months improves physical activity and sleep quality in children with autism: a randomized controlled trial

Purpose

Sleep disturbances are prevalent in autistic children. The emergence of telehealth offers new possibilities for remote professional intervention. By combining telehealth with parental support, this study aims to explore a novel family-based model to enhance moderate-to-vigorous physical activity (MVPA) and improve sleep quality in children with autism.

Methods

Thirty-four autistic children (mean age = 15.7 years) were randomly assigned to either a 6-month intervention group or a control group. Both groups received standard physical education classes at school. The intervention group received additional after-school telehealth support. MVPA and sleep quality were assessed 1 week before the intervention and at the 6-month follow-up.

Results

After 6 months, children in the intervention group nearly doubled their daily MVPA compared to the control group (Cohen's d = 8.34, CI95% = 6.17-10.52). Actigraphy-assessed sleep efficiency was notably higher (d = 2.35, CI95% = 1.44-3.26), and there were reductions in wake time (d = 1.65, CI95% = 0.84-2.46), sleep fragmentation (d = 0.80, CI95% = 0.07-1.52), and sleep latency (d = 0.82, CI95% = 0.09-1.54) were all reduced. These improvements in objective sleep metrics were corroborated by subjective assessments using the Sleep Disturbance Scale for Children (d = 0.86, CI95% = 0.13-1.59).

Conclusions

Telehealth combined with parental support addresses barriers to enhancing health behaviors at home. This innovative model not only improves after-school MVPA and sleep quality in autistic children but also holds significant potential for benefiting other populations requiring remote support.

Clinical Trial Registration

https://clinicaltrials.gov/study/NCT06444659?id=NCT06444659&rank=1 (NCT06444659).

A systematic review of research reporting practices in observational studies examining associations between 24-h movement behaviors and indicators of health using compositional data analysis

Background

Compositional data analysis (CoDA) techniques are well suited for examining associations between 24-h movement behaviors (i.e., sleep, sedentary behavior, physical activity) and indicators of health given they recognize these behaviors are co-dependent, representing relative parts that make up a whole day. Accordingly, CoDA techniques have seen increased adoption in the past decade, however, heterogeneity in research reporting practices may hinder efforts to synthesize and quantify these relationships via meta-analysis. This systematic review described reporting practices in studies that used CoDA techniques to investigate associations between 24-h movement behaviors and indicators of health.

Methods

A systematic search of eight databases was conducted, in addition to supplementary searches (e.g., forward/backward citations, expert consultation). Observational studies that used CoDA techniques involving log-ratio transformation of behavioral data to examine associations between time-based estimates of 24-h movement behaviors and indicators of health were included. Reporting practices were extracted and classified into seven areas: (1) methodological justification, (2) behavioral measurement and data handling strategies, (3) composition construction, (4) analytic plan, (5) composition-specific descriptive statistics, (6) model results, and (7) auxiliary information. Study quality and risk of bias were assessed by the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-sectional Studies.

Results

102 studies met our inclusion criteria. Reporting practices varied considerably across areas, with most achieving high standards in methodological justification, but inconsistent reporting across all other domains. Some items were reported in all studies (e.g., how many parts the daily composition was partitioned into), whereas others seldom reported (e.g., definition of a day: midnight-to-midnight versus wake-to-wake). Study quality and risk of bias was fair in most studies (85%).

Conclusions

Current studies generally demonstrate inconsistent reporting practices. Consistent, clear and detailed reporting practices are evidently needed moving forward as the field of time-use epidemiology aims to accurately capture and analyze movement behavior data in relation to health outcomes, facilitate comparisons across studies, and inform public health interventions and policy decisions. Achieving consensus regarding reporting recommendations is a key next step.

Supplementary Information

The online version contains supplementary material available at 10.1186/s44167-024-00062-8.

Association Between Physical Activity, Sedentary Behaviors, and Sleep-Related Outcomes Among Cancer Survivors: a Cross-Sectional Study

BACKGROUND

Limited research has examined the association between moderate to vigorous physical activity (MVPA), sedentary behavior (SB), and sleep-related outcomes in cancer survivors. Therefore, this study aimed to examine these associations using a nationally representative sample of US adults.

METHODS

Data from the 2005-2018 National Health and Nutrition Examination Survey (NHANES) were analyzed. A total of 3229 adults with cancer histories were included. Physical activity was measured through accelerometry, and questions on daily activities, sedentary time, and sleep were collected during the household interview. Weighted multivariable analyses were conducted after accounting for the complex sampling design of the NHANES dataset.

RESULTS

After adjustments, physical activity and SB outcomes were associated with several self-reported sleep-related parameters. Increases in minutes of self-reported MVPA and SB were associated with a decreased likelihood of reporting ≥ 8 h of sleep (OR = 0.92, 95% CI = 0.86, 0.99 and OR = 0.88, 95% CI = 0.82, 0.95). Converse associations were found between device-measured MVPA and SB with the likelihood of reporting often/always feeling overly sleepy during the day (OR = 0.86, 95% CI = 0.75 and OR = 1.13, 95% CI = 1.05, respectively). However, an increased likelihood of waking up too early in the morning (OR = 1.22, 95% CI = 1.04) was observed with increases in minutes of device-measured MVPA.

CONCLUSIONS

A sensible strategy to decrease the frequency of sedentary breaks and increase minutes of physical activity throughout the day may reduce sleep complaints reported in cancer survivors.

The Sleep Parameters of Olympic Athletes: Characteristics and Assessment Instruments

This systematic review aims to identify the sleep parameters of Olympic athletes and the instruments used to assess and monitor the sleep of these athletes. The search was conducted until February 2023 and was performed in PubMed, Web of Science, and Scopus databases. This systematic review has included studies that investigated at least one of the following sleep parameters: total sleep time (TST), sleep onset latency (SOL), sleep efficiency (SE), awakenings after sleep onset (WASO), quality of sleep, daytime sleepiness, and chronotype; the participants were Olympic athletes. The search returned a total of 280 studies. After screening based on exclusion and inclusion criteria, 11 studies were included. The main results demonstrate that Olympic athletes have TST of 06:10 h, SE of 84%, SOL of 28 min, and WASO of 49 min. The most predominant chronotype is indifferent; over half of the athletes have poor sleep quality and complaints. Furthermore, actigraphy was the most used method to assess sleep. It is concluded that Olympic athletes have TST, SE, and WASO poor than the recommended values. In addition, sleep complaints and poor sleep quality were also observed. Among the objective sleep assessment methods, actigraphy was the method most frequently used in this population.

Comparing national device-based physical activity surveillance systems: a systematic review

BACKGROUND

Physical activity surveillance systems are important for public health monitoring but rely mostly on self-report measurement of physical activity. Integration of device-based measurements in such systems can improve population estimates, however this is still relatively uncommon in existing surveillance systems. This systematic review aims to create an overview of the methodology used in existing device-based national PA surveillance systems.

METHODS

Four literature databases (PubMed, Embase.com, SPORTDiscus and Web of Science) were searched, supplemented with backward tracking. Articles were included if they reported on population-based (inter)national surveillance systems measuring PA, sedentary time and/or adherence to PA guidelines. When available and in English, the methodological reports of the identified surveillance studies were also included for data extraction.

RESULTS

This systematic literature search followed the PRISMA guidelines and yielded 34 articles and an additional 18 methodological reports, reporting on 28 studies, which in turn reported on one or multiple waves of 15 different national and 1 international surveillance system. The included studies showed substantial variation between (waves of) systems in number of participants, response rates, population representativeness and recruitment. In contrast, the methods were similar on data reduction definitions (e.g. minimal number of valid days, non-wear time and necessary wear time for a valid day).

CONCLUSIONS

The results of this review indicate that few countries use device-based PA measurement in their surveillance system. The employed methodology is diverse, which hampers comparability between countries and calls for more standardized methods as well as standardized reporting on these methods. The results from this review can help inform the integration of device-based PA measurement in (inter)national surveillance systems.

Exploring Factors Associated With Accelerometer Validity Among Ethnically Diverse Toddlers

PURPOSE

Studying physical activity in toddlers using accelerometers is challenging due to noncompliance with wear time (WT) and activity log (AL) instructions. The aims of this study are to examine relationships between WT and AL completion and (1) demographic and socioeconomic variables, (2) parenting style, and (3) whether sedentary time differs by AL completion.

METHODS

Secondary analysis was performed using baseline data from a community wellness program randomized controlled trial for parents with toddlers (12-35 mo). Parents had toddlers wear ActiGraph wGT3x accelerometers and completed ALs. Valid days included ≥600-minute WT. Analysis of variance and chi-square analyses were used.

RESULTS

The sample (n = 50) comprised racial and ethnically diverse toddlers (mean age = 27 mo, 58% male) and parents (mean age = 31.7 y, 84% female). Twenty-eight families (56%) returned valid accelerometer data with ALs. Participants in relationships were more likely to complete ALs (P < .05). Toddler sedentary time did not differ between those with ALs and those without.

CONCLUSIONS

We found varied compliance with WT instructions and AL completion. Returned AL quality was poor, presenting challenges in correctly characterizing low-activity counts to improve internal validity of WT and physical activity measures. Support from marital partners may be important for adherence to study protocols.

Using functional principal component analysis (FPCA) to quantify sitting patterns derived from wearable sensors

BACKGROUND

Sedentary behavior (SB) is a recognized risk factor for many chronic diseases. ActiGraph and activPAL are two commonly used wearable accelerometers in SB research. The former measures body movement and the latter measures body posture. The goal of the current study is to quantify the pattern and variation of movement (by ActiGraph activity counts) during activPAL-identified sitting events, and examine associations between patterns and health-related outcomes, such as systolic and diastolic blood pressure (SBP and DBP).

METHODS

The current study included 314 overweight postmenopausal women, who were instructed to wear an activPAL (at thigh) and ActiGraph (at waist) simultaneously for 24 hours a day for a week under free-living conditions. ActiGraph and activPAL data were processed to obtain minute-level time-series outputs. Multilevel functional principal component analysis (MFPCA) was applied to minute-level ActiGraph activity counts within activPAL-identified sitting bouts to investigate variation in movement while sitting across subjects and days. The multilevel approach accounted for the nesting of days within subjects.

RESULTS

At least 90% of the overall variation of activity counts was explained by two subject-level principal components (PC) and six day-level PCs, hence dramatically reducing the dimensions from the original minute-level scale. The first subject-level PC captured patterns of fluctuation in movement during sitting, whereas the second subject-level PC delineated variation in movement during different lengths of sitting bouts: shorter (< 30 minutes), medium (30 -39 minutes) or longer (> 39 minute). The first subject-level PC scores showed positive association with DBP (standardized β ^ : 2.041, standard error: 0.607, adjusted p = 0.007), which implied that lower activity counts (during sitting) were associated with higher DBP.

CONCLUSION

In this work we implemented MFPCA to identify variation in movement patterns during sitting bouts, and showed that these patterns were associated with cardiovascular health. Unlike existing methods, MFPCA does not require pre-specified cut-points to define activity intensity, and thus offers a novel powerful statistical tool to elucidate variation in SB patterns and health.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03473145; Registered 22 March 2018; https://clinicaltrials.gov/ct2/show/NCT03473145 ; International Registered Report Identifier (IRRID): DERR1-10.2196/28684.

Physical Activity Associates with T1rho MRI of Femoral Cartilage After Anterior Cruciate Ligament Reconstruction

PURPOSE

Less physical activity has been associated with systemic biomarkers of cartilage breakdown after anterior cruciate ligament reconstruction (ACLR). However, previous research lacks analysis of deleterious cartilage compositional changes and objective physical activity after ACLR. The purpose of this study was to determine the association between physical activity quantified via accelerometer-based measures of daily steps and time in moderate-to-vigorous physical activity (MVPA), and T1rho magnetic resonance imaging (MRI) of the femoral articular cartilage, a marker of proteoglycan density in individuals with ACLR.

METHODS

Daily steps and MVPA were assessed over 7 d using an accelerometer worn on the hip in 26 individuals between 6 and 12 months after primary unilateral ACLR. Resting T1rho MRI was collected bilaterally, and T1rho MRI interlimb ratios (ILR: ACLR limb/contralateral limb) were calculated for lateral and medial femoral condyle regions of interest. We conducted univariate linear regression analyses to determine associations between T1rho MRI ILRs and daily steps and MVPA with and without controlling for sex.

RESULTS

Greater T1rho MRI ILR of the central lateral femoral condyle, indicative of less proteoglycan density in the ACLR limb, was associated with greater time in MVPA ( R2 = 0.178, P = 0.032). Sex-adjusted models showed significant interaction terms between daily steps and sex in the anterior ( P = 0.025), central ( P = 0.002), and posterior ( P = 0.002) medial femoral condyle.

CONCLUSIONS

Lesser physical activity may be a risk factor for maintaining cartilage health after ACLR; additionally, the relationship between physical activity and cartilage health may be different between males and females.

Accelerometry-assessed sleep clusters and cardiometabolic risk factors in adolescents

OBJECTIVE

This study aimed to identify sleep clusters based on objective multidimensional sleep characteristics and test their associations with adolescent cardiometabolic health.

METHODS

The authors included 1090 participants aged 14.3 to 16.4 years (mean = 15.2 years) who wore 7-day accelerometers during the 15-year follow-up of the German Infant Study on the influence of Nutrition Intervention PLUS environmental and genetic influences on allergy development (GINIplus) and the Influence of Lifestyle factors on the development of the Immune System and Allergies in East and West Germany (LISA) birth cohorts. K-means cluster analysis was performed across 12 sleep characteristics reflecting sleep quantity, quality, schedule, variability, and regularity. Cardiometabolic risk factors included fat mass index (FMI), blood pressure, triglycerides, high-density lipoprotein cholesterol, high-sensitivity C-reactive protein, and insulin resistance (n = 505). Linear and logistic regression models were examined.

RESULTS

Five sleep clusters were identified: good sleep (n = 337); delayed sleep phase (n = 244); sleep irregularity and variability (n = 108); fragmented sleep (n = 313); and prolonged sleep latency (n = 88). The "prolonged sleep latency" cluster was associated with increased sex-scaled FMI (β = 0.39, 95% CI: 0.15-0.62) compared with the "good sleep" cluster. The "sleep irregularity and variability" cluster was associated with increased odds of high triglycerides only in male individuals (odds ratio: 9.50, 95% CI: 3.22-28.07), but this finding was not confirmed in linear models.

CONCLUSIONS

The prolonged sleep latency cluster was associated with higher FMI in adolescents, whereas the sleep irregularity and variability cluster was specifically linked to elevated triglycerides (≥1.7 mmol/L) in male individuals.

Are reallocations of time between physical activity, sedentary behaviour and sleep associated with low back pain? A compositional data analysis

Objectives

The aim of this cross-sectional study was to explore the associations of reallocating time between moderate- to vigorous-intensity physical activity (MVPA), light-intensity physical activity (LPA), sedentary behaviour (SB) and sleep with occurrence, frequency and intensity of low back pain (LBP) among adults using compositional isotemporal substitution analysis.

Methods

A total of 2333 participants from the general adult population completed the Daily Activity Behaviours Questionnaire asking about their time-use composition consisting of sleep, SB, LPA and MVPA, and they self-reported their frequency and intensity of LBP in the past year.

Results

Regression analyses adjusted for age, sex, body mass index, smoking, stress, education and socioeconomic status found that the time-use composition is associated with the frequency (p=0.009) and intensity of LBP (p<0.001). Reallocating time from SB or LPA to sleep was associated with lower frequency and intensity of LBP (p<0.05). Reallocating time from MVPA to sleep, SB or LPA and from SB to LPA was associated with a lower intensity of LBP (p<0.05). For example, reallocating 30 min/day from SB to sleep was associated with 5% lower odds (95% CI: 2% to 8%, p=0.001) of experiencing LBP more frequently, and 2% lower LBP intensity (95% CI: 1% to 3%, p<0.001).

Conclusion

LBP sufferers may benefit from getting additional sleep and spending more time in LPA, while engaging less in SB and MVPA. These reallocations of time may be meaningful from clinical and public health perspectives.

Age-Related Differences in Accelerometer-Assessed Physical Activity and Sleep Parameters Among Children and Adolescents With and Without Autism Spectrum Disorder: A Meta-Analysis

Importance

Physical inactivity and sleep disorders are health-related concerns of youth with autism spectrum disorder (ASD) that can persist from childhood and exacerbate core symptoms. However, evidence on group differences in accelerometer-assessed physical activity and sleep parameters among youth with and without ASD is inconclusive and age-specific effects remain unclear.

Objective

To synthesize evidence on group differences in accelerometer-assessed physical activity and sleep parameters and examine the moderating effects of age between children and adolescents with and without ASD.

Data Sources

American Psychological Association PsychInfo, CINAHL Ultimate, ERIC, MEDLINE, SPORTDiscus with Full Text, and Web of Science from inception to February 2023.

Study Selection

Two independent reviewers screened articles for observational research comparing accelerometer-assessed physical activity levels and sleep parameters in children and adolescents with and without ASD.

Data Extraction and Synthesis

After developing a standardized form, relevant data were extracted. Quality was assessed using the McMaster Critical Review Form and rated based on sample, measurement, and analyses. The Preferring Reporting Items for Systematic Reviews and Meta-Analyses guideline was followed.

Main Outcomes and Measures

The primary outcomes were actigraphy-measured MVPA, sleep latency, sleep efficiency, total sleep time, and wake after sleep onset. Data were pooled using a random-effects model. Hedges g was used to express the effect size index. Meta-regression on age was also performed to investigate the potential moderating effects.

Results

Collectively, 1757 studies were initially identified. Among 104 articles that were assessed, 28 were included, comprising moderate-to-vigorous physical activity (MVPA), 4 sleep parameters, and 73 independent effect sizes. A total of 28 studies were included in analysis, comprising 805 children and adolescents with ASD and 1573 without ASD (age range, 5.1-16.9 years). Compared with peers without ASD, children and adolescents with ASD had a small-to-moderate difference in MVPA (g = -0.450; 95% CI, -0.622 to -0.277), total sleep time (g = -0.332; 95% CI, -0.574 to -0.090), sleep efficiency (g = -0.424; 95% CI, -0.645 to -0.203), and a moderate difference in sleep latency (g = 0.514; 95% CI, 0.351 to 0.677) measured by actigraphy. Children and adolescents with ASD experienced an age-related decline in moderate-to-vigorous physical activity (β = -0.049 [95% CI, -0.097 to -0.001]; P = .045), indicating that younger children with ASD showed a smaller difference in MVPA compared with their peers without ASD. Moderating effects of age on sleep parameters were not significant.

Conclusions and Relevance

The findings of this meta-analysis suggested that children and adolescents with ASD had lower MVPA and worse sleep than peers without ASD, and the difference in MVPA varied with age. These findings reinforce the need for public health initiatives aimed at reducing these group disparities.

Overview of the impact of sleep monitoring on optimal performance, immune system function and injury risk reduction in athletes: A narrative review

Sleep is essential for a range of physiological and mental functions in professional athletes. There is proof that athletes may experience lower quality and quantity of sleep. While adequate sleep has been shown to have restorative effects on the immune system and endocrine system, facilitate nervous system recovery and the metabolic cost of wakefulness, and play a significant role in learning, memory, and synaptic plasticity, which can affect sports recovery, injury risk reduction, and performance. Sports performance may suffer significantly from a lack of sleep, especially under maximal and long-term exercise. Due to the potential harm, these factors may do to an athlete's endocrine, metabolic, and nutritional health, sports performance is impacted by reduced sleep quality or quantity. There are several neurotransmitters associated with the sleep-wake cycle that have been discovered. They comprise cholinergic hormone, orexin, melanin, galanin, serotonin, gamma-aminobutyric acid, histamine, and serotonin. Therefore, dietary modifications that affect the neurotransmitters in the brain also may affect sleep; particularly for athletes who require more physical and psychological recovery owing to the tremendous physiological and psychological demands placed on them during training and performance. This review explores the variables that influence the quantity and quality of sleep-in populations of athletes and assesses their possible effects. In addition, several recommendations for improving sleep are presented. Even though there has been much research on variables that impact sleep, future studies may highlight the significance of these aspects for athletes.

Using mobile health to encourage physical activity in individuals with intellectual disability: a pilot mixed methods feasibility study

Background

Many individuals with intellectual disability (ID) have a sedentary lifestyle. Few interventions aimed at increasing their level of physical activity (PA) have shown lasting effects.

Aim

To assess the feasibility and acceptability of a pilot intervention study using innovative mobile health (mHealth) support systems to encourage PA in individuals with ID.

Methods

Nine individuals with ID and a low level of PA, aged 16-36 years, were included in the present convergent triangulation mixed method design. Two mHealth support systems (apps) were developed and tested. PA was measured with a Fitbit smartwatch, accelerometer, the International Physical Activity Questionnaire-Short Form (IPAQ-S), and Goal attainment scaling. Data were collected through online pre-, mid- (4 weeks), and post-intervention (12 weeks) questionnaires and activity trackers. Semi-structured qualitative interviews with participants and/or a family or staff member were held after the 12-week follow-up. Data were analyzed using conventional nonparametric statistics and thematic analyses.

Results

The response rate and retention to the trial were 16% and 100%, respectively. Data quality was high, except for missing data from Fitbit activity trackers of approximately 30% from the 4- and 12-week follow-up stages. The feasibility challenges with activity trackers include rashes, size, non-acceptance, and loss of motivation. Participants and family members/staff reported interest in the study theme and were pleased with the data collection method. All but one participant achieved their PA goals. Most participants reported being satisfied with the apps as they were enjoyable or provided a reminder for performing physical and other activities. Social support for PA among family members also increased. However, app support from staff and family members was needed, and apps were not used regularly. Two of nine participants (22%) had increased their PA measured as steps per day with Fitbit at the 12-week follow-up.

Conclusions

The acceptability and feasibility of using tailored mobile applications in natural settings to increase PA among adults with ID are promising. This study aligns with previous studies in showing the challenges to increasing PA, which requires the inclusion of family members, staff, and stakeholders. The intervention requires modifications before a randomized controlled trial can be conducted.

Co-design and content validity of the movement measurement in the early years (MoveMEY) tool for assessing movement behaviour of pre-school aged children

BACKGROUND

Movement behaviours (physical activity, sedentary behaviour, and sleep) are important for pre-school children's health and development. Currently, no tools with appropriate content validity exist that concurrently capture these movement behaviours in young children. The aim of this study was to co-design and assess the content validity of a novel tool to concurrently measure movement behaviours in pre-school aged children (aged 3-4 years).

METHODS

We followed four distinct steps to develop and assess the content validity of Movement Measurement in the Early Years (MoveMEY): (1) We conducted an extensive literature search, to identify pre-existing proxy measurement tools (questionnaires and diaries) to inform the design of a novel tool, which aimed to effectively capture movement behaviour guidelines of pre-school aged children. (2) We facilitated focus group discussions with parents and carers of pre-school aged children (n = 11) and (3) a qualitative survey with free text responses was completed by topic relevant researchers (n = 6), to co-design the measurement tool. (4) We assessed the content validity of the developed tool, MoveMEY, through interviews with parents of pre-school aged children (n = 12) following piloting of the tool.

RESULTS

We developed an initial version of MoveMEY based on the format of an existing questionnaire and by mapping the content of questions to the guidelines. Co-design of MoveMEY resulted in changes to the format (e.g. short questionnaire to a seven-day diary) and content (e.g. inclusion of 'general information' questions on illness, disabilities and sleep disturbances; question on screen time before bed). Content validity assessment demonstrated that the items of MoveMEY were relevant and comprehensive for the assessment of children's movement behaviours. MoveMEY was felt to be comprehensible, however, parental suggestions were implemented to finalise and improve MoveMEY (e.g. adding examples to questions aiming to detect moderate to vigorous physical activity).

CONCLUSION

MoveMEY is the first co-designed measurement tool that has relevance for assessing the movement behaviour guidelines of pre-school aged children. Parent/carer and topic relevant researcher involvement throughout the development process resulted in a seven-day daily reported activity diary that is comprehensive of children's movement behaviours and comprehensible to parents and carers.

Assessment of 24-hour physical behaviour in adults via wearables: a systematic review of validation studies under laboratory conditions

BACKGROUND

Wearable technology is used by consumers and researchers worldwide for continuous activity monitoring in daily life. Results of high-quality laboratory-based validation studies enable us to make a guided decision on which study to rely on and which device to use. However, reviews in adults that focus on the quality of existing laboratory studies are missing.

METHODS

We conducted a systematic review of wearable validation studies with adults. Eligibility criteria were: (i) study under laboratory conditions with humans (age ≥ 18 years); (ii) validated device outcome must belong to one dimension of the 24-hour physical behavior construct (i.e., intensity, posture/activity type, and biological state); (iii) study protocol must include a criterion measure; (iv) study had to be published in a peer-reviewed English language journal. Studies were identified via a systematic search in five electronic databases as well as back- and forward citation searches. The risk of bias was assessed based on the QUADAS-2 tool with eight signaling questions.

RESULTS

Out of 13,285 unique search results, 545 published articles between 1994 and 2022 were included. Most studies (73.8% (N = 420)) validated an intensity measure outcome such as energy expenditure; only 14% (N = 80) and 12.2% (N = 70) of studies validated biological state or posture/activity type outcomes, respectively. Most protocols validated wearables in healthy adults between 18 and 65 years. Most wearables were only validated once. Further, we identified six wearables (i.e., ActiGraph GT3X+, ActiGraph GT9X, Apple Watch 2, Axivity AX3, Fitbit Charge 2, Fitbit, and GENEActiv) that had been used to validate outcomes from all three dimensions, but none of them were consistently ranked with moderate to high validity. Risk of bias assessment resulted in 4.4% (N = 24) of all studies being classified as "low risk", while 16.5% (N = 90) were classified as "some concerns" and 79.1% (N = 431) as "high risk".

CONCLUSION

Laboratory validation studies of wearables assessing physical behaviour in adults are characterized by low methodological quality, large variability in design, and a focus on intensity. Future research should more strongly aim at all components of the 24-hour physical behaviour construct, and strive for standardized protocols embedded in a validation framework.

Accelerometer-measured physical activity, sedentary behavior, and sleep in children with cerebral palsy and their adherence to the 24-hour activity guidelines

AIM

To measure and describe the 24-hour activities (i.e. physical activity, sedentary behavior, and sleep) and to examine adherence to the 24-hour activity guidelines among children with cerebral palsy (CP) using actigraphy.

METHOD

Children's 24-hour activities were recorded over 7 days using hip- and wrist-worn ActiGraph wGT3X-BT accelerometers.

RESULTS

In total, 362 days and 340 nights from 54 children with CP (Gross Motor Function Classification System [GMFCS] levels I-III; 44% females; median age [range] 6 years 6 months [3-12 years]) were included. Mean (SD) daily wear time was 746.2 (48.9) minutes, of which children spent on average 33.8% in light physical activity (251.6 [58.7] minutes per day), 5.2% in moderate-to-vigorous physical activity (38.5 [20.1] minutes per day), and the remaining 61.1% being sedentary (456.1 [80.4] minutes per day). Physical activity decreased while sedentary behavior increased with increasing GMFCS level. In total, 13% of all children met the physical activity recommendations, and 35% met the age-appropriate sleep duration recommendation. The proportion of children meeting the combined 24-hour guidelines for physical activity and sleep was low (5.9%), especially in those classified in GMFCS level III (0%).

INTERPRETATION

The observed low 24-hour guideline adherence rates emphasize the importance of considering the entire continuum of movement behaviors in the care of children with CP, in efforts to promote healthy lifestyle behaviors and prevent negative health outcomes.

The Dyadic Interplay Between Relationship Satisfaction, Perceived Positive and Negative Social Control, and a Reduction of Sedentary Behavior Time

BACKGROUND

Both the close relationship processes and health model and the dyadic health influence model posit that beliefs about the relationship (e.g., relationship satisfaction) and influence strategies (e.g., social control) serve as mediators of health behavior change. The evidence for such mediation is limited.

PURPOSE

This study investigated two competing hypotheses that arise from these models: (1) perceived use of positive and negative social control (attempts to influence the partner's behaviors) predict sedentary behavior (SB) indirectly, via relationship satisfaction; or (2) relationship satisfaction predicts SB indirectly, via positive and negative social control.

METHODS

Data from 320 dyads (target persons and their partners, aged 18-90 years), were analyzed using mediation models. SB time was measured with GT3X-BT accelerometers at Time 1 (T1; baseline) and Time 3 (T3; 8 months following baseline). Relationship satisfaction and social control were assessed at T1 and Time 2 (T2; 2 months following baseline).

RESULTS

Higher T1 relationship satisfaction among target persons predicted target persons' reporting of higher T2 negative control from partners, which in turn predicted lower T3 SB time among target persons. Lower T1 relationship satisfaction among partners predicted target persons' reporting of higher T2 perceived negative control from partners, which predicted lower T3 SB time among target persons. On average, both members of the dyad reported moderate-to-high relationship satisfaction and low-to-moderate negative control.

CONCLUSIONS

In contrast to very low levels of negative control, its low-to-moderate levels may be related to beneficial behavioral effects (lower SB time) among target persons reporting moderate-to-high relationship satisfaction.

The Sleep Parameters of Paralympic Athletes: Characteristics and Assessment Instruments

CONTEXT

Sleep serves many important functions for athletes, particularly in the processes of learning, memory, recovery, and cognition.

OBJECTIVES

Define the sleep parameters of Paralympic athletes and identify the instruments used to assess and monitor sleep Paralympic athletes.

EVIDENCE ACQUISITION

This systematic review was carried out based on the PRISMA guidelines. The survey was conducted in April 2020, the searches were carried out again in September 2021 to check whether there were new scientific publications in the area of sleep and Paralympic sport, searches were performed in the following databases: PubMed, Web of Science, Scopus, SPORTDiscus, Virtual Health Library (BIREME), and SciELO. This systematic review has included studies that investigated at least one of the following sleep parameters: total sleep time, sleep latency, sleep efficiency, number of awakenings, quality of sleep, daytime sleepiness, and chronotype; the participants were comprised of athletes with disabilities. Studies published at any time in English, Portuguese, and Spanish, were included.

EVIDENCE SYNTHESIS

Data extraction and study selection were performed by 2 researchers independently, and a third author was consulted as necessary. The search returned a total of 407 studies. Following the screening based on exclusion and inclusion criteria, a total of 13 studies were considered. Paralympic athletes have a low amount (7.06 h) of sleep with poor quality and sleep latency (28.05 min), and 57.2% have daytime sleepiness, with the majority belonging to the indifferent chronotype (53, 5%). Moreover, 11 studies assess sleep using subjective instruments (questionnaires), and 2 studies used an objective instrument (actigraphy).

CONCLUSIONS

Sleep disorders are common among Paralympic athletes, poor sleep quality and quantity, and high rates of daytime sleepiness. Subjective methods are most commonly used to assess sleep.

The Role of Dysfunctional Sleep Beliefs in Mediating the Outcomes of Web-Based Cognitive Behavioral Therapy for Insomnia in Community-Dwelling Older Adults: Protocol for a Single-Group, Nonrandomized Trial

BACKGROUND

Sleeping well is an essential part of good health. Older adult populations report a high rate of sleep problems, with recent studies suggesting that cognitive processes as well as behavioral and hyperarousal-related mechanisms could be important factors in the development and maintenance of insomnia. Individuals who have an asynchronous or uncoupled sleep pattern and sleep appraisal-those who complain about their sleep but do not have poor sleep quality, and vice versa-might show differences in subjective sleep and sleep perceptions and other characteristics that could impact their treatment outcomes following cognitive behavioral therapy for insomnia (CBT-I).

OBJECTIVE

The purpose of this protocol is to describe the rationale and methods for a nonrandomized, single-arm trial assessing objective and subjective sleep quality in community-dwelling older adults aged 60-80 years with synchronous sleep patterns and sleep appraisal compared to those in older adults with asynchronous sleep patterns and sleep appraisal. The trial will further examine the role of cognitive, behavioral, and hyperarousal processes in mediating the treatment outcomes of web-based CBT-I.

METHODS

This trial aims to recruit a sample of 60 participants, who will be assigned to 1 of 4 sleep groups based on their sleep pattern and sleep appraisal status: complaining good sleepers, complaining poor sleepers, noncomplaining good sleepers, and noncomplaining poor sleepers, respectively. The trial will be completed in 2 phases: phase 1 will assess objective sleep (measured via wrist actigraphy) and subjective (self-reported) sleep. Phase 2 will investigate the impact of a web-based CBT-I program on the sleep outcomes of individuals with uncoupled sleep compared to that of individuals without uncoupled sleep, as well as the mediators of CBT-I.

RESULTS

Recruitment began in March 2020, and the last participants were recruited by March 2021. A total of 65 participants completed phases 1 and 2. Data analysis for phase 1 was finished in December 2021, and data analysis for phase 2 was finalized in July 2022. The results for phase 1 were submitted for publication in March 2022, and those for phase 2 will be submitted by the end of December 2022.

CONCLUSIONS

This trial will provide guidance on factors that contribute to the variability of sleep in older adults and their sleep outcomes following CBT-I. The outcomes of this study could be valuable for future research attempting to tailor CBT-I to individual needs.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN12619001509156; https://tinyurl.com/69hhdu2w.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/32705.

Dyadic reciprocal associations between self-efficacy and planning predict sedentary behaviour

OBJECTIVES

There are two alternative hypotheses regarding bidirectional associations between self-efficacy and planning in predicting health behaviour change: self-efficacy may establish planning (cultivation hypothesis) or planning may enable the formation of self-efficacy (enabling hypothesis). This study investigates the order in which these two social cognitions are linked in adult-adult dyads in the context of sedentary behaviours (SB).

DESIGN

A longitudinal study with 4 measurement points, spanning 8 months.

METHODS

A total of 320 dyads (age: 18-90 years) were enrolled. Dyads included a focus person (who received the recommendation to reduce SB and intended to change their SB), and their partners, who were willing to support the focus persons and intended to reduce their own SB as well. Data were collected at Time 1 (T1), Time 2 (1 week later, T2), Time 3 (T3, 2 months after T1) and Time 4 (T4, 8 months after T1). SB was measured with accelerometers at (T1 and T4). Mediation models with individual and dyadic reciprocal effects were tested with path analyses.

RESULTS

Only one indirect effect was found: A higher level of partners' SB reduction-specific self-efficacy at T2 was related to the focus person's more frequent planning to reduce SB at T3, which, in turn, predicted lower SB time among partners at T4.

CONCLUSIONS

The findings provide partial support for the cultivation model (self-efficacy prompting planning) and for dyadic reciprocal associations in the context of SB time reduction among adult dyads.

Sociodemographic differences in 24-hour time-use behaviours in New Zealand children

BACKGROUND

The time that children spend in physical activity, sedentary behaviour, and sleep each day (i.e., 24-h time-use behaviours), is related to physical and mental health outcomes. Currently, there is no comprehensive evidence on New Zealand school-aged children's 24-h time-use behaviours, adherence to the New Zealand 24-h Movement Guidelines, and how these vary among different sociodemographic groups.

METHODS

This study utilises data from the 8-year wave of the Growing Up in New Zealand longitudinal study. Using two Axivity AX3 accelerometers, children's 24-h time-use behaviours were described from two perspectives: activity intensity and activity type. Compositional data analysis techniques were used to explore the differences in 24-h time-use compositions across various sociodemographic groups.

RESULTS

Children spent on average, 31.1%, 22.3%, 6.8%, and 39.8% of their time in sedentary, light physical activity, moderate-to-vigorous physical activity, and sleep, respectively. However, the daily distribution of time in different activity types was 33.2% sitting, 10.8% standing, 7.3% walking, 0.4% running, and 48.2% lying. Both the activity intensity and activity type compositions varied across groups of child ethnicity, gender, and household income or deprivation. The proportion of children meeting each of the guidelines was 90% for physical activity, 62.5% for sleep, 16% for screen time, and 10.6% for the combined guidelines. Both gender and residence location (i.e., urban vs. rural) were associated with meeting the physical activity guideline, whereas child ethnicity, mother's education and residence location were associated with meeting the screen time guideline. Child ethnicity and mother's education were also significantly associated with the adherence to the combined 24-h Movement Guidelines.

CONCLUSIONS

This study provided comprehensive evidence on how New Zealand children engage in 24-h time-use behaviours, adherence to the New Zealand 24-h Movement Guidelines, and how these behaviours differ across key sociodemographic groups. These findings should be considered in designing future interventions for promoting healthy time-use patterns in New Zealand children.

Fewer daily steps are associated with greater cartilage oligomeric matrix protein response to loading post-ACL reconstruction

Aberrant joint loading contributes to the development of posttraumatic knee osteoarthritis (PTOA) following anterior cruciate ligament reconstruction (ACLR); yet little is known about the association between joint loading due to daily walking and cartilage health post-ACLR. Accelerometer-based measures of daily steps and cadence (i.e., rate of steps/min) provide information regarding daily walking in a real-world setting. The purpose of this study was to determine the association between changes in serum cartilage oligomeric matrix protein (COMP; %∆COMP), a mechanosensitive biomarker that is associated with osteoarthritis progression, following a standardized walking protocol and daily walking in individuals with ACLR and uninjured controls. Daily walking was assessed over 7 days using an accelerometer worn on the right hip in 31 individuals with ACLR and 21 controls and quantified as mean steps/day and time spent in ≥100 steps/min. Serum COMP was measured before and following a 3000-step walking protocol at a preferred speed. %∆COMP was calculated as a change in COMP relative to the prewalking value. Linear regressions were used to examine associations between daily walking and %∆COMP after adjusting for preferred speed. Fewer daily steps (ΔR²  = 0.18, p = 0.02) and fewer minutes spent in ≥100 steps/min (ΔR²  = 0.16, p = 0.03) were associated with greater %∆COMP following walking in individuals with ACLR; no statistically significant associations existed in controls (daily steps: ΔR²  = 0.03, p = 0.47; time ≥100 steps/min: ΔR²  < 0.01, p = 0.81). Clinical significance: Individuals with ACLR who engage in less daily walking undergo greater %ΔCOMP, which may represent greater cartilage degradation or turnover in response to walking.

Wrist accelerometry for monitoring dementia agitation behaviour in clinical settings: A scoping review

Agitated behaviour among elderly people with dementia is a challenge in clinical management. Wrist accelerometry could be a versatile tool for making objective, quantitative, and long-term assessments. The objective of this review was to summarise the clinical application of wrist accelerometry to agitation assessments and ways of analysing the data. Two authors independently searched the electronic databases CINAHL, PubMed, PsycInfo, EMBASE, and Web of Science. Nine (n = 9) articles were eligible for a review. Our review found a significant association between the activity levels (frequency and entropy) measured by accelerometers and the benchmark instrument of agitated behaviour. However, the performance of wrist accelerometry in identifying the occurrence of agitation episodes was unsatisfactory. Elderly people with dementia have also been monitored in existing studies by investigating the at-risk time for their agitation episodes (daytime and evening). Consideration may be given in future studies on wrist accelerometry to unifying the parameters of interest and the cut-off and measurement periods, and to using a sampling window to standardise the protocol for assessing agitated behaviour through wrist accelerometry.

More Physical Activity, More Work Engagement? A Northern Finland Birth Cohort 1966 Study

OBJECTIVE

To examine the role of physical activity (PA) and sedentary behavior (SED) for work engagement.

METHODS

We used data from Northern Finland Birth Cohort 1966 Study ( n = 3046 to 4356) to analyze self-reported weekly leisure-time physical activity (LTPA), daily leisure-time sitting time (LTST) and work engagement. PA and SED 24-hour were also measured with accelerometer for 14 days. The data were analyzed using linear regression analyses.

RESULTS

High self-reported LTPA and sports participation were associated with higher work engagement and its subdimensions. High self-reported ST was associated with lower work engagement, vigor, and absorption. Accelerometer-measured light PA was associated with higher work engagement and vigor, and accelerometermeasured steps were linked to higher vigor. Accelerometer-measured SED was associated with lower work engagement, vigor, and dedication.

CONCLUSIONS

Self-reported and accelerometer-measured PA and SED may play a role in people's work engagement.

Lack of validity of free-living physical activity energy expenditure estimated from ActiGraph equations in severely obese women: A doubly labelled water study

The current study aimed to investigate the validity of three ActiGraph predictive equations that are available to estimate free-living physical activity energy expenditure (PAEE) in women with severe obesity. The study included 20 women with class III obesity (age: 22-38 years). During 14 days of free-living conditions, total energy expenditure was measured using the doubly labelled water method; in addition, participants wore a triaxial accelerometer (model GT3X+) on the hip. The resting metabolic rate was measured by indirect calorimetry. At group level, the Freedson VM3 Combination was found to be more precise (bias = -61 kcal/day) than the Williams Work-Energy (bias = -283 kcal/day) and the Freedson Combination equations (bias = -186 kcal/day) for estimating PAEE. However, the three predictive equations had a wider limit of agreement (Williams Work-Energy [258, -824 kcal/day], Freedson Combination equations [324, -697 kcal/day] and Freedson VM3 Combination [424, -546 kcal/day]), indicating great uncertainty of the estimate. In conclusion, a wide variation was observed in the performance of different ActiGraph equations in estimating free-living PAEE among women with class III obesity. Therefore, our data do not support the use of these equations, and more studies are needed to improve predictive performance in free-living conditions.

Quality Evaluation of Free-living Validation Studies for the Assessment of 24-Hour Physical Behavior in Adults via Wearables: Systematic Review

Background

Wearable technology is a leading fitness trend in the growing commercial industry and an established method for collecting 24-hour physical behavior data in research studies. High-quality free-living validation studies are required to enable both researchers and consumers to make guided decisions on which study to rely on and which device to use. However, reviews focusing on the quality of free-living validation studies in adults are lacking.

Objective

This study aimed to raise researchers’ and consumers’ attention to the quality of published validation protocols while aiming to identify and compare specific consistencies or inconsistencies between protocols. We aimed to provide a comprehensive and historical overview of which wearable devices have been validated for which purpose and whether they show promise for use in further studies.

Methods

Peer-reviewed validation studies from electronic databases, as well as backward and forward citation searches (1970 to July 2021), with the following, required indicators were included: protocol must include real-life conditions, outcome must belong to one dimension of the 24-hour physical behavior construct (intensity, posture or activity type, and biological state), the protocol must include a criterion measure, and study results must be published in English-language journals. The risk of bias was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 tool with 9 questions separated into 4 domains (patient selection or study design, index measure, criterion measure, and flow and time).

Results

Of the 13,285 unique search results, 222 (1.67%) articles were included. Most studies (153/237, 64.6%) validated an intensity measure outcome such as energy expenditure. However, only 19.8% (47/237) validated biological state and 15.6% (37/237) validated posture or activity-type outcomes. Across all studies, 163 different wearables were identified. Of these, 58.9% (96/163) were validated only once. ActiGraph GT3X/GT3X+ (36/163, 22.1%), Fitbit Flex (20/163, 12.3%), and ActivPAL (12/163, 7.4%) were used most often in the included studies. The percentage of participants meeting the quality criteria ranged from 38.8% (92/237) to 92.4% (219/237). On the basis of our classification tree to evaluate the overall study quality, 4.6% (11/237) of studies were classified as low risk. Furthermore, 16% (38/237) of studies were classified as having some concerns, and 72.9% (173/237) of studies were classified as high risk.

Conclusions

Overall, free-living validation studies of wearables are characterized by low methodological quality, large variability in design, and focus on intensity. Future research should strongly aim at biological state and posture or activity outcomes and strive for standardized protocols embedded in a validation framework. Standardized protocols for free-living validation embedded in a framework are urgently needed to inform and guide stakeholders (eg, manufacturers, scientists, and consumers) in selecting wearables for self-tracking purposes, applying wearables in health studies, and fostering innovation to achieve improved validity.

Assessment of 24-hour physical behaviour in children and adolescents via wearables: a systematic review of free-living validation studies

Objectives

Studies that assess all three dimensions of the integrative 24-hour physical behaviour (PB) construct, namely, intensity, posture/activity type and biological state, are on the rise. However, reviews on validation studies that cover intensity, posture/activity type and biological state assessed via wearables are missing.

Design

Systematic review. The risk of bias was evaluated by using the QUADAS-2 tool with nine signalling questions separated into four domains (ie, patient selection/study design, index measure, criterion measure, flow and time).

Data sources

Peer-reviewed validation studies from electronic databases as well as backward and forward citation searches (1970–July 2021).

Eligibility criteria for selecting studies

Wearable validation studies with children and adolescents (age <18 years). Required indicators: (1) study protocol must include real-life conditions; (2) validated device outcome must belong to one dimension of the 24-hour PB construct; (3) the study protocol must include a criterion measure; (4) study results must be published in peer-reviewed English language journals.

Results

Out of 13 285 unique search results, 76 articles with 51 different wearables were included and reviewed. Most studies (68.4%) validated an intensity measure outcome such as energy expenditure, but only 15.9% of studies validated biological state outcomes, while 15.8% of studies validated posture/activity type outcomes. We identified six wearables that had been used to validate outcomes from two different dimensions and only two wearables (ie, ActiGraph GT1M and ActiGraph GT3X+) that validated outcomes from all three dimensions. The percentage of studies meeting a given quality criterion ranged from 44.7% to 92.1%. Only 18 studies were classified as ‘low risk’ or ‘some concerns’.

Summary

Validation studies on biological state and posture/activity outcomes are rare in children and adolescents. Most studies did not meet published quality principles. Standardised protocols embedded in a validation framework are needed.

PROSPERO registration number

CRD42021230894.

Parental Views on the Acceptability and Feasibility of Measurement Tools Used to Assess Movement Behaviour of Pre-School Children: A Qualitative Study

Movement behaviours (physical activity, sedentary behaviour, and sleep) are important for the health and development of pre-school children (aged 3-4 years). There is limited qualitative research examining the acceptability and feasibility of tools used to assess movement behaviours in pre-schoolers. This study explored parental views on various measurement tools in three deprived areas in England, UK (West Yorkshire, County Durham and Northumberland). The study consisted of a demonstration of the different tools (accelerometers, a diary and a questionnaire), directly followed by focus group discussions. Three focus group discussions with a total of eleven parents and carers were transcribed verbatim and analysed using thematic analysis. Findings revealed four main themes: (1) importance of contextual information when using any measurement tool (e.g., child illness, capturing different routines); (2) practical issues associated with devices (e.g., aversion to devices being attached directly to the skin of their child; concern of larger devices during sleep time); (3) encouraging children to wear a device (e.g., making devices attractive to children-'superpowers'); and (4) presentation of diaries and questionnaires (e.g., age-appropriate movement activities, preference for real-time recording over recall). Practical recommendations for the use of the tools to measure movement behaviours of pre-school children are provided.

The Eating Healthy and Daily Life Activities (EHDLA) Study

BACKGROUND

Childhood obesity is one of the greatest public health concerns facing advanced societies, Spain being one of the countries with the highest incidence. In this sense, the Region of Murcia has been pointed out as the Spanish autonomous community with the highest prevalence of excess weight among young people. More specifically, the Valle de Ricote has shown an even greater proportion of excess weight among young people. Several sociodemographic, environmental, lifestyle, health-related, cognitive, and psychological factors are related to excess weight. Based on the lack of information, this research project will try to provide relevant information to design intervention programs, as well as to implement effective public policies to try and reverse this alarming situation. Therefore, this research project aims (1) to obtain cross-sectional and longitudinal data on the excess weight and their potential sociodemographic, environmental, lifestyle, health-related, cognitive, and psychological factors associated among adolescents from the Valle de Ricote (Region of Murcia, Spain) (aged 12-17 years), and (2) to examine the association between excess weight and their potential sociodemographic, environmental, lifestyle, health-related, cognitive, and psychological factors associated among this population.

METHODS

A cross-sectional study and follow-up study will be performed. This research project will involve adolescents using a simple random sampling technique. A total of three secondary schools from the Valle de Ricote (Region of Murcia, Spain) will be included in this project. The minimum sample size will be 1138, establishing a 95% confidence interval, a 40% prevalence of excess weight, a 3% margin of error, and a non-response rate of 10%. Primary outcome measures will be: (1) anthropometric measurements, (2) sociodemographic factors, (3) environmental factors, (4) lifestyle factors, (5) health-related factors, (6) cognitive factors, and (7) psychological factors.

CONCLUSION

This research project will aim to determine the prevalence of excess weight and interrelate their potential sociodemographic, environmental, lifestyle, health-related, cognitive, and psychological factors associated. The obtained results will help to manage and propose possible multidisciplinary interventions and strategies in order to prevent and reduce the excess weight in adolescents from the Valle de Ricote. Furthermore, orientations will be given to transfer the obtained results to the public sector to evaluate or change the adopted policies.

The effects of napping on night‐time sleep in healthy young adults

The discrepancies in the effects of napping on sleep quality may be due to differences in methodologies, napping behaviours, and daytime activity levels across studies. We determined whether napping behaviours and daytime activity levels are associated with night-time sleep fragmentation and sleep quality in young adults. A total of 62 healthy adults (mean [SD] age 23.5 [4.2] years) completed screening questionnaires for sleep habits, physical activity, medical and psychological history. Actigraphy was used to record sleep including naps. The fragmentation algorithm (K_RA ) was applied to the actigraphic data to measure night-time sleep fragmentation. We classified participants' nap frequency as "non-nappers" (0 naps/8 days), "moderate nappers" (1-2 naps/8 days) or "frequent nappers" (≥3 naps/8 days) naps. Nap duration was defined as "short" (≤60 min) or "long" (>60 min). Naps' proximity to the night sleep episode was defined as "early" (≥7 h) and "late" (<7 h) naps. Outcome variables were night-time K_RA and actigraphic sleep variables. Frequent nappers had a significantly higher K_RA than moderate nappers (p < 0.01) and non-nappers (p < 0.02). Late naps were associated with poorer measures of night sleep quality versus early naps (all p ≤ 0.02). Nap duration and daytime activity were not associated with significant differences in the outcome variables (all p > 0.05). K_RA correlated with sleep duration, sleep efficiency, and awakenings (r = -0.32, -0.32, and 0.53, respectively; all p < 0.05). Frequent napping and late naps may be associated with increased sleep fragmentation and poorer sleep quality, reflected in longer sleep onsets and increased awakenings. These findings have implications for public health sleep hygiene recommendations.

Peer-led physical activity intervention for girls aged 13 to 14 years: PLAN-A cluster RCT

Background

Increasing physical activity among girls is a public health priority. Peers play a central role in influencing adolescent behaviour. Peer-led interventions may increase physical activity in adolescent girls, and a feasibility trial had shown that PLAN-A (Peer-led physical Activity iNtervention for Adolescent girls) had evidence of promise to increase physical activity in adolescent girls.

Objective

The objective was to test whether or not PLAN-A can increase adolescent girls’ physical activity, relative to usual practice, and be cost-effective.

Design

This was a two-arm, cluster-randomised controlled trial, including an economic evaluation and a process evaluation.

Participants

State-funded secondary schools in the UK with girls in Year 9 (aged 13–14 years) participated in the trial. All Year 9 girls in participating schools were eligible.

Randomisation

Schools were the unit of allocation. They were randomised by an independent statistician, who was blinded to school identities, to the control or intervention arm, stratified by region and the England Index of Multiple Deprivation score.

Intervention

The intervention comprised peer nomination (i.e. identification of influential girls), train the trainers (i.e. training the instructors who delivered the intervention), peer supporter training (i.e. training the peer-nominated girls in techniques and strategies underpinned by motivational theory to support peer physical activity increases) and a 10-week diffusion period.

Outcomes

The primary outcome was accelerometer-assessed mean weekday minutes of moderate to vigorous physical activity among Year 9 girls. The follow-up measures were conducted 5–6 months after the 10-week intervention, when the girls were in Year 10 (which was also 12 months after the baseline measures). Analysis used a multivariable, mixed-effects, linear regression model on an intention-to-treat basis. Secondary outcomes included weekend moderate to vigorous physical activity, and weekday and weekend sedentary time. Intervention delivery costs were calculated for the economic evaluation.

Results

A total of 33 schools were approached; 20 schools and 1558 pupils consented. Pupils in the intervention arm had higher Index of Multiple Deprivation scores than pupils in the control arm. The numbers randomised were as follows: 10 schools (n = 758 pupils) were randomised to the intervention arm and 10 schools (n = 800 pupils) were randomised to the control arm. For analysis, a total of 1219 pupils provided valid weekday accelerometer data at both time points (intervention, n = 602; control, n = 617). The mean weekday moderate to vigorous physical activity was similar between groups at follow-up. The central estimate of time spent engaging in moderate to vigorous physical activity was 2.84 minutes lower in the intervention arm than in the control arm, after adjustment for baseline mean weekday moderate to vigorous physical activity, the number of valid days of data and the stratification variables; however, this difference was not statistically significant (95% confidence interval –5.94 to 0.25; p = 0.071). There were no between-arm differences in the secondary outcomes. The intervention costs ranged from £20.85 to £48.86 per pupil, with an average cost of £31.16.

Harms

None.

Limitations

The trial was limited to south-west England.

Conclusions

There was no evidence that PLAN-A increased physical activity in Year 9 girls compared with usual practice and, consequently, it was not cost-effective.

Future work

Future work should evaluate the utility of whole-school approaches to promote physical activity in schools.

Trial registration

This trial is registered as ISRCTN14539759.

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. 10, No. 6. See the NIHR Journals Library website for further project information. This trial was designed and delivered in collaboration with the Bristol Randomised Trials Collaboration (BRTC), a United Kingdom Clinical Research Commission (UKCRC)-registered Clinical Trials Unit that, as part of the Bristol Trials Centre, is in receipt of NIHR Clinical Trials Unit support funding. The sponsor of this trial was University of Bristol, Research and Enterprise Development www.bristol.ac.uk/red/. The costs of delivering the intervention were funded by Sport England.

The 3-Month Effectiveness of a Stratified Blended Physiotherapy Intervention in Patients With Nonspecific Low Back Pain: Cluster Randomized Controlled Trial

Background

Patient education, home-based exercise therapy, and advice on returning to normal activities are established physiotherapeutic treatment options for patients with nonspecific low back pain (LBP). However, the effectiveness of physiotherapy interventions on health-related outcomes largely depends on patient self-management and adherence to exercise and physical activity recommendations. e-Exercise LBP is a recently developed stratified blended care intervention comprising a smartphone app integrated with face-to-face physiotherapy treatment. Following the promising effects of web-based applications on patients’ self-management skills and adherence to exercise and physical activity recommendations, it is hypothesized that e-Exercise LBP will improve patients’ physical functioning.

Objective

This study aims to investigate the short-term (3 months) effectiveness of stratified blended physiotherapy (e-Exercise LBP) on physical functioning in comparison with face-to-face physiotherapy in patients with nonspecific LBP.

Methods

The study design was a multicenter cluster randomized controlled trial with intention-to-treat analysis. Patients with nonspecific LBP aged ≥18 years were asked to participate in the study. The patients were treated with either stratified blended physiotherapy or face-to-face physiotherapy. Both interventions were conducted according to the Dutch physiotherapy guidelines for nonspecific LBP. Blended physiotherapy was stratified according to the patients’ risk of developing persistent LBP using the Keele STarT Back Screening Tool. The primary outcome was physical functioning (Oswestry Disability Index, range 0-100). Secondary outcomes included pain intensity, fear-avoidance beliefs, and self-reported adherence. Measurements were taken at baseline and at the 3-month follow-up.

Results

Both the stratified blended physiotherapy group (104/208, 50%) and the face-to-face physiotherapy group (104/208, 50%) had improved clinically relevant and statistically significant physical functioning; however, there was no statistically significant or clinically relevant between-group difference (mean difference −1.96, 95% CI −4.47 to 0.55). For the secondary outcomes, stratified blended physiotherapy showed statistically significant between-group differences in fear-avoidance beliefs and self-reported adherence. In patients with a high risk of developing persistent LBP (13/208, 6.3%), stratified blended physiotherapy showed statistically significant between-group differences in physical functioning (mean difference −16.39, 95% CI −27.98 to −4.79) and several secondary outcomes.

Conclusions

The stratified blended physiotherapy intervention e-Exercise LBP is not more effective than face-to-face physiotherapy in patients with nonspecific LBP in improving physical functioning in the short term. For both stratified blended physiotherapy and face-to-face physiotherapy, within-group improvements were clinically relevant. To be able to decide whether e-Exercise LBP should be implemented in daily physiotherapy practice, future research should focus on the long-term cost-effectiveness and determine which patients benefit most from stratified blended physiotherapy.

Trial Registration

ISRCTN Registry 94074203; https://doi.org/10.1186/ISRCTN94074203

International Registered Report Identifier (IRRID)

RR2-https://doi.org/10.1186/s12891-020-3174-z

Influence of Epoch Length and Recording Site on the Relationship Between Tri-Axial Accelerometry-Derived Physical Activity Levels and Structural, Functional, and Hemodynamic Properties of Central and Peripheral Arteries

Background

It remains to be established to what extent physical activity (PA) levels among individuals are independently associated with deviations from the “optimal” state of the arterial system. Accelerometers have been proposed as means to obtain reliable, objective, and more comprehensive data of PA. Decisions at the time of data collection/processing could influence the association between accelerometry-derived indices and arterial properties.

Objectives

(i) To identify to what extent the strength of association between arterial properties and accelerometer-derived indices depend on the recording site and/or the epoch length; (ii) to determine whether some arterial characteristics (hemodynamic vs. structural vs. functional) or regions (elastic vs. transitional vs. muscular arteries; central vs. peripheral) have higher levels of association with accelerometry-derived indices.

Methods

Physical activity (PA), cardiovascular risk factors (CRFs), and cardiovascular properties were evaluated in 60 volunteers (general population; age: 23–62 years; women: 43%). PA was measured daily for 7 days (free-living situation; triaxial-accelerometers ActiGraph-GT3X+; hip and wrist; “Worn-to-wrist” option) and raw data was converted at epoch lengths of 1, 5, 10, 30, and 60-s. PA-related energy expenditure, daily time in moderate-to-vigorous PA, steps/minute, and counts-per-minute for vector magnitude were calculated. The cardiovascular evaluation included hemodynamic (central and peripheral pressure), structural (diameters and intima-media thickness), and functional (local and regional stiffness) parameters of carotids, femoral, and brachial arteries, and carotid-femoral and carotid-radial pathways. Arterial z-scores were obtained using age-related equations derived from healthy participants not exposed to CRFs (n = 1,688; age: 2–84 years; female: 51.2%) to evaluate at which degree each parameter deviates from the “optimal” value.

Methods

In general, hip recordings outperformed those obtained on the wrist regarding the strength of association with arterial parameters. Accelerometer-derived indices and their association with arterial properties vary depending on the recording site and epoch length. PA indices are stronger associated with functional (local) than structural variables and with central than peripheral arteries.

Conclusions

Regardless of the PA index, there were independent associations with central artery characteristics, which reinforces that these territories would be the most related to PA levels. Differences in data acquisition and processing could lead to differences in conclusions when addressing the association between accelerometer-derived indices and the cardiovascular system.

Measurement Methods of Fatigue, Sleepiness, and Sleep Behaviour Aboard Ships: A Systematic Review

Since seafarers are known to be exposed to numerous job-related stress factors that can cause fatigue, sleepiness, and disturbed sleep behaviour, the aim of this review was to provide an overview of the subjective and objective measurement methods of these strains. Using a systematic review, 166 studies were identified within the period of January 2010 to December 2020 using the PubMed database. Of the 21 studies selected, 13 used both subjective and objective measurement methods. Six studies used only subjective and two studies only objective methods. For subjective assessment, 12 different questionnaires could be identified as well as activity and sleeping logs. Actigraphy and reaction time tests (RTT) were the most common objective methods. In single cases, electrooculography (EOG), pupillometry and ambulatory polysomnography (PSG) were used. Measurement-related limitations due to vessel-related impacts were less often reported than expected. No restrictions of daily routines on board were described, and only single-measurement disturbances due to ship movements were mentioned. The present literature review reveals that there are various routines to measure fatigue, sleepiness, and sleep behaviour on board. A combination of subjective and objective methods often appears to be beneficial. The frequent use of actigraphy and RTT on board suggests good feasibility and reliable measurements with these methods. The use of ambulatory PSG in maritime-like contexts suggests that this method would also be feasible on board.

Quantitative assessment of sitting time in ambulant adults with Muscular Dystrophy

BACKGROUND

Current investigations into physical behaviour in Muscular Dystrophy (MD) have focussed largely on physical activity (PA). Negative health behaviours such as sedentary behaviour (Physical Behaviour) and sitting time (Posture Classification) are widely recognised to negatively influence health, but by contrast are poorly reported, yet could be easier behaviours to modify.

METHODS

14 ambulant men with MD and 12 healthy controls (CTRL) subjects completed 7-days of free-living with wrist-worn accelerometry, assessing physical behaviour (SB or PA) and Posture Classification (Sitting or Standing), presented at absolute (minutes) or relative (% Waking Hours). Participant body composition (Fat Mass and Fat Free Mass) were assessed by Bioelectrical Impedance, while functional status was assessed by 10 m walk test and a functional scale (Swinyard Scale).

RESULTS

Absolute Sedentary Behaviour (2.2 Hours, p = 0.025) and Sitting Time (1.9 Hours, p = 0.030 was greater in adults with MD compared to CTRL and Absolute Physical Activity (3.4 Hours, p < 0.001) and Standing Time (3.2 Hours, p < 0.001) was lower in adults with MD compared to CTRL. Absolute hours of SB was associated with Fat Mass (Kg) (R = 0.643, p < 0.05) in ambulatory adults with MD.

DISCUSSION

This study has demonstrated increased Sedentary Behaviour (2.2 hours) and Sitting time (1.9 Hours) in adults with MD compared to healthy controls. Extended waking hours in sitting and SB raises concerns with regards to progression of potential cardio-metabolic diseases and co-morbidities in MD.

Nighttime sleep and physical activity in 6-7 month-old infants

This study examined associations between objectively-measured nighttime sleep duration and physical activity in a sample of 6-7 month-old infants (N=93). The study also investigated relationships between infant sleep and demographic and environmental characteristics. Cross-sectional relationships were assessed using linear regression analyses. Nighttime sleep duration was positively associated with physical activity levels. Nighttime sleep duration was greater when infants had a consistent bedtime, slept in a separate room, were male, and had mothers who reported having a college education or greater. These findings can inform the development of interventions that aim to improve infant sleep.

Can individual, dyadic, or collaborative planning reduce sedentary behavior? A randomized controlled trial

RATIONALE

Although effects of individual planning interventions on physical activity (PA) are well established, less is known about the relationships between planning and sedentary behavior (SB).

OBJECTIVE

This study evaluated the efficacy of individual planning, dyadic planning (i.e., joint planning, targeting the behavior of one person only: the target person), and collaborative planning (i.e., joint planning and joint behavioral performance) on sedentary behavior among dyads.

METHODS

Dyads (N = 320 target persons and their partners, aged 18-90 years) were randomized into three PA planning conditions (individual, dyadic, or collaborative) or an active (education) control condition. Main outcomes, i.e., sedentary time, proportion of time spent in SB and light-intensity PA, proportion of time spent in SB and total PA were measured with GT3X-BT accelerometers at baseline, 1-week follow-up, and 36-week follow-up. Two-level models with measurement points nested in participants were fit, separately for target persons and partners.

RESULTS

Findings for target persons obtained at 1-week follow-up indicated that in the collaborative planning condition SB time significantly decreased, compared to the control condition (p = .013). There was an improvement in the proportion of time spent in SB and light-intensity PA (p = .019), and the proportion of time spent in SB and total PA (p = .018), indicating that SB time was displaced by PA. Effects of individual and dyadic planning were not significant, compared to the control condition. None of interventions had a significant effect on SB indices at 36-week follow-up. Regarding dyadic partners, there were no effects of planning interventions at 1-week follow-up or 36-week follow-up, compared to the control condition.

CONCLUSIONS

Collaborative planning may prompt a short-term reduction of SB time and result in a shift towards a healthier balance between SB time and PA time among target persons, who did not adhere to PA guidelines at baseline.

Biological changes in the pregnancy-postpartum period and subsequent cardiometabolic risk-UPSIDE MOMS: A research protocol

Multiple physiological changes occur in pregnancy as a woman's body adapts to support the growing fetus. These pregnancy-induced changes are essential for fetal growth, but the extent to which they reverse after pregnancy remains in question. For some women, physiological changes persist after pregnancy and may increase long-term cardiometabolic disease risk. The National Institutes of Health-funded study described in this protocol addresses a scientific gap by characterizing weight and biological changes during pregnancy and an extended postpartum period in relation to cardiometabolic risk. We use a longitudinal repeated measures design to prospectively examine maternal health from early pregnancy until 3 years postpartum. The aims are: (1) identify maternal weight profiles in the pregnancy-postpartum period that predict adverse cardiometabolic risk profiles three years postpartum; (2) describe immune, endocrine, and metabolic biomarker profiles in the pregnancy-postpartum period, and determine their associations with cardiometabolic risk; and (3) determine how modifiable postpartum health behaviors (diet, physical activity, breastfeeding, sleep, stress) (a) predict weight and cardiometabolic risk in the postpartum period; and (b) moderate associations between postpartum weight retention and downstream cardiometabolic risk. The proposed sample is 250 women. This study of mothers is conducted in conjunction with the Understanding Pregnancy Signals and Infant Development study, which examines child health outcomes. Biological and behavioral data are collected in each trimester and at 6, 12, 24, and 36 months postpartum. Findings will inform targeted health strategies that promote health and reduce cardiometabolic risk in childbearing women.

Quality of Life Associates With Moderate to Vigorous Physical Activity Following Anterior Cruciate Ligament Reconstruction

CONTEXT

Higher knee function is linked to psychological readiness to return to sport following anterior cruciate ligament reconstruction (ACLR). Individuals with ACLR participate in less physical activity compared to matched uninjured controls, yet the association between knee function and physical activity following ACLR remains unclear.

OBJECTIVE

To determine the association between patient-reported knee function measured with the Knee Injury and Osteoarthritis Outcomes Score Quality of Life (KOOS-QOL), daily steps, and minutes spent in moderate to vigorous physical activity (MVPA) in individuals with ACLR. Secondarily, we determined associations between KOOS-QOL, daily steps, and MVPA in individuals with ACLR who presented with (symptomatic) and without (asymptomatic) clinically meaningful knee related symptoms.

DESIGN

Cross-sectional study.

SETTING

Laboratory, Free-living conditions.

PATIENTS OR OTHER PARTICIPANTS

Sixty-six individuals with primary unilateral ACLR (55% female, 22±4 years, 28±33 months post-ACLR, BMI: 24.2±2.9 kg/m2).

OUTCOME MEASURE(S)

We collected KOOS and retrospectively stratified participants into those with (symptomatic [n=30]) or without (asymptomatic [n=36]) clinically meaningful knee related symptoms based on previously defined KOOS cutoffs. We assessed daily steps and MVPA from ActiGraph GT9X Link accelerometers which each participant wore on the right hip for 7 days. We conducted linear regressions to determine associations between KOOS-QOL, daily steps, and MVPA.

RESULTS

No significant associations existed in the entire sample between KOOS-QOL and daily steps (ΔR2=0.01, P=0.50) or MVPA (ΔR2=0.01, P=0.36). In symptomatic individuals, greater KOOS-QOL associated with greater MVPA (ΔR2=0.12, P=0.05,). No significant associations existed between KOOS-QOL, daily steps, and MVPA in the asymptomatic group.

CONCLUSIONS

Symptomatic individuals with ACLR who spent more time in MVPA reported higher quality of life.