'Legs feed the wolf': An evolutionary perspective on psychosocial stress, physical activity, and their associations with telomere length in NCAA student-athletes and non-athletes

Psychosocial stress negatively impacts our mental and physical health, predisposing us to illness, worsened mental health, and accelerated aging. Conversely, regular physical activity, such as exercise and sports training, positively impacts our health. These opposing effects are intriguing because psychosocial stress and physical activity were inextricably linked throughout human evolution. Large populations of humans have only recently begun transitioning into more sedentary lifestyles, uncoupling psychosocial stress from physical activity. Improving our understanding of these two factors and their interactions will, in turn, improve our understanding of the mechanisms through which psychosocial stress impacts health in both modern and ancestral human populations.My dissertation examines whether physical activity moderates the association between psychosocial stress and capillary blood telomere length in NCAA student-athletes and their non- athlete counterparts in the general student population. My first paper develops an in-depth comparison of psychosocial stress in these two groups using a suite of psychosocial stress surveys and an adapted cognitive interview protocol. Student-athletes (N=65) reported lower levels of current perceived stress and anxiety symptoms (p<0.05) but similar levels of childhood psychosocial stress, recent exposure to external stressors, and depressive symptoms compared to non-athletes (N=57). My second paper utilized self-report and objective measures of physical activity (i.e., accelerometry) to compare physical activity patterns in these groups. Student- athletes (N=60) both self-reported higher levels of physical activity and recorded higher levels of activity via accelerometry (p>0.001) compared to non-athletes (N=50). Interestingly, categorical measures of activity levels (i.e., time spent in moderate-to-vigorous physical activity) identified Rowers as the most active among student-athletes, but continuous measures of activity levels (e.g., total physical activity level) identified Track and Field athletes as the most active (p>0.05 for both comparisons).My third and final paper tested whether higher physical activity weakened the association between childhood psychosocial stress and telomere length estimated from capillary blood collected on Hemaspot HF devices (N=111). Telomeres are DNA sequences that protect the ends of chromosomes. They shorten with cell replication, age, and oxidative stress, leading to functional decline with age and worsened health outcomes. Importantly, psychosocial stress is thought to accelerate TL shortening. My a priori analyses did not support a direct association between psychosocial stress, physical activity, or the interaction of these variables and telomere length. However, a post hoc analysis found that individuals who recorded higher total physical activity demonstrated a positive association between childhood psychosocial stress and telomere length (i.e., higher childhood stress predicted longer telomeres) while individuals who recorded lower total physical activity had a negative association (i.e., higher childhood psychosocial stress predicted shorter telomeres).My results do not offer explicit support for the hypothesis that physical activity moderates the effects of psychosocial stress on telomere length. However, my project adds to the literature in at least several ways. It produced a novel and much-needed comparison of psychosocial stress between NCAA student-athletes and non-athletes. It illustrated and validated several data collection techniques for psychosocial stress and physical activity. Further, my telomere findings offer an exciting direction for the future exploration of psychosocial stress- physical activity interactions. Lastly, this work improves our overall understanding of NCAA student-athletes' mental and physical health and how their unique circumstances intersect with the ongoing effects of the COVID-19 pandemic. (PsycInfo Database Record (c) 2023 APA, all rights reserved)

Device-Measured Change in Physical Activity in Primary School Children During the UK COVID-19 Pandemic Lockdown: A Longitudinal Study.

BACKGROUND: Lockdown measures, including school closures, due to the COVID-19 pandemic have caused widespread disruption to children's lives. The aim of this study was to explore the impact of a national lockdown on children's physical activity using seasonally matched accelerometry data. METHODS: Using a pre/post observational design, 179 children aged 8 to 11 years provided physical activity data measured using hip-worn triaxial accelerometers worn for 5 consecutive days prepandemic and during the January to March 2021 lockdown. Multilevel regression analyses adjusted for covariates were used to assess the impact of lockdown on time spent in sedentary and moderate to vigorous physical activity. RESULTS: A 10.8-minute reduction in daily time spent in moderate to vigorous physical activity (standard error: 2.3 min/d, P < .001) and a 33.2-minute increase in daily sedentary activity (standard error: 5.5 min/d, P < .001) were observed during lockdown. This reflected a reduction in daily moderate to vigorous physical activity for those unable to attend school (-13.1 [2.3] min/d, P < .001) during lockdown, with no significant change for those who continued to attend school (0.4 [4.0] min/d, P < .925). CONCLUSION: These findings suggest that the loss of in-person schooling was the single largest impact on physical activity in this cohort of primary school children in London, Luton, and Dunstable, United Kingdom.

iPhone Accelerometry Provides a Sensitive In-Home Assessment of Age-Related Changes in Standing Balance.

Remote health monitoring has become increasingly important, especially in aging populations. We aimed to identify tasks that are sensitive to age-related changes in balance during fully remote, at-home balance assessment. Participants were 12 healthy young adults (mean age = 26.08 years, range: 18-33) and 12 healthy older adults (mean age = 67.33 years, range: 60-75). Participants performed standing tasks monitored via video conference while their balance was quantified using a custom iPhone application measuring mediolateral center of mass acceleration. We included three stances (feet together, tandem, and single leg) with eyes open or closed, with or without a concurrent cognitive task. Older adults demonstrated significantly more variable center of mass accelerations in tandem (p = .04, ηp2=.25) and significantly higher (p < .01, ηp2=.45) and more variable (p < .01, ηp2=.44) center of mass accelerations in single leg compared with young adults. We also observed that as task challenge increased, balance dual-task cost diminished for older, but not young, adults.

Physical and respiratory function of people following hospital discharge for COVID-19

Background: People following hospital discharge for COVID-19 may experience persisting negative effects of the disease. Investigation of the short and long-term effects are necessary to refer people to appropriate rehabilitation services for functional recovery. Aim(s): To evaluate physical and respiratory function of people with COVID-19 shortly after hospital discharge. Method(s): Assessments were undertaken at three time points: (i) within three weeks following hospital discharge (A1);(ii) at three months (A2);and (iii) six months following discharge (A3). Measures were collected of: fatigue (Fatigue Severity Scale;FSS), lower-limb function (1 minute sit-to-stand test;1-STS), pulmonary function (spirometry), dyspnea (MRC Scale) and physical activity in daily life (PADL) (accelerometry). Result(s): Forty people were included (18[45%] men;55[51-60] years;length of hospital stay: 8+/-6 days;FSS: 54.5[44.2-59];1-STS: 21+/-7;FVC %pred: 87+/-15;FEV1 %pred: 88+/-15;FEV1/FVC (%): 83+/-6;4,284+/-2,460 steps/day;MRC: 3+/-1). There was a: reduction in fatigue from A1 to A2 (mean difference [95% CI] -1.8 [-2,5;-1.2])] and from A1 to A3 (-2.2 [-2.9;-1.4]);an improvement in lower-limb function from A1 to A2 (5.1 [2.2;7,9]) and from A1 to A3 (5.6 [3.18;8]);an improvement in FVC %pred from A1 to A3 (5.9 [1.5;10.2]);and a reduction on dyspnea from A1 to A2 (-1.2 [-0.6;-0.3]) and from A1 to A3 [-1.2 (-0.6;-1,8)]. No change in PADL was found. Conclusion(s): People with COVID-19 post-hospital discharge present fatigue, functional impairment, dyspnea, poor PADL and normal lung function. Improvements in dyspnea, fatigue and lower-limb function were observed at three and six-months follow-up.

Use of awake prone positioning in acute COVID-19

Introduction: Awake prone positioning (APP) may reduce ventilation-perfusion mismatch in the context of acute respiratory distress syndrome. The Intensive Care Society recommends its use in COVID-19 to improve oxygenation and reduce risk of progression to invasive mechanical ventilation. This audit project measured the use of APP on an Acute Respiratory Care Unit (ARCU). Method(s): Observations and patient outcomes were recorded for non-intubated patients where a clinical decision had been made to prone. The activPALTM accelerometer was used as an objective measure of APP (prone or lateral-lie positioning). Analysis was performed using STATA v16. Result(s): Between September 2020 and February 2021, 19 individuals with a median age of 68 years were included. 74% were male. In the first 48 hours, 747 person-hours of data were recorded, with 358 person-hours spent in APP. Eight individuals spent at least 50% of their first 48 hours in APP. Lateral lie was better tolerated than full prone positioning, with a median (interquartile range, IQR) of 11.6 (8.0, 20.2) hours spent in lateral lie and median (IQR) of 1.6 (0.5, 8.3) hours spent fully proned in the first 48 hours. Median (interquartile range, IQR) improvement from baseline in respiratory rate/oxygenation (ROX) index at 48 hours was +1.65 (0.90, 1.89). Median (IQR) ROX index at 12 hours for individuals not in APP was 4.80 (3.04, 8.51) and 10.41 (9.09, 11.42) for individuals who were fully proned. Nine individuals were admitted to intensive care, 13 survived to discharge. Conclusion(s): Accelerometry is an objective method to measure time spent in APP and showed that lateral lie was preferred to full prone position in this cohort. Trends suggest possible improvement in ROX, although numbers were small.

Physical Activity Time and Intensity in Physical Education During the COVID-19 Pandemic.

With the COVID-19 outbreak, schools have experienced difficulty providing moderate-to-vigorous physical activity (MVPA) to their students, which should normally account for at least 50% of children's physical education (PE) class time. We aimed to determine the intensity of physical activity (PA) within PE classes at various grade levels to compare children's in-class PA with the World Health Organization's (WHO) recommended guidelines. Thus, 301 students (1st to 12th grade) participated in the investigation. Children were evaluated during the PE classes with different typologies and durations. We assessed PA intensity using accelerometry and grouped data into either sedentary-to-light PA (SEDLI) or MVPA. Each child was assessed using both the time spent in PA (hours:minutes:seconds) and the percentage of time spent in PA versus other class activities. We found that, in the second-grade level group (fifth and sixth grades), girls spent more time in MVPA intensity than boys. Additionally, two-hour PE classes doubled the SEDLI for students in the third-grade group, and polythematic classes (those with more than one sport) promoted more MVPA level time than monothematic classes (only one sport). Concerning PA intensity during PE classes, 31-43% of the PE class total time was spent in MVPA but presented short duration and did not usually persist for 10 consecutive minutes (59% of the time). Children spent a large amount of time at the SEDLI intensity, considered insufficient for PA health benefits. Finally, to meet WHO guidelines for PA intensity, PE classes will need to increase MVPA time and reduce non-active periods between activities.

Sedentary behaviour, physical activity, and sleep among office workers during the COVID-19 pandemic: a comparison of Brazil and Sweden.

BACKGROUND: The COVID-19 pandemic has affected the physical behaviours of office workers worldwide, but studies comparing physical behaviours between countries with similar restrictions policies are rare. This study aimed to document and compare the 24-hour time-use compositions of physical behaviours among Brazilian and Swedish office workers on working and non-working days during the pandemic. METHODS: Physical behaviours were monitored over 7 days using thigh-worn accelerometers in 73 Brazilian and 202 Swedish workers. Daily time-use compositions were exhaustively described in terms of sedentary behaviour (SED) in short (< 30 min) and long (≥30 min) bouts, light physical activity (LPA), moderate-to-vigorous physical activity (MVPA), and time-in-bed. We examined differences between countries using MANOVA on data processed according to compositional data analysis. As Swedish workers had the possibility to do hybrid work, we conducted a set of sensitivity analyses including only data from days when Swedish workers worked from home. RESULTS: During working days, Brazilian office workers spent more time SED in short (294 min) and long (478 min) bouts and less time in LPA (156 min) and MVPA (50 min) than Swedish workers (274, 367, 256 and 85 min, respectively). Time spent in bed was similar in both groups. Similar differences between Brazilians and Swedes were observed on non-working days, while workers were, in general, less sedentary, more active and spent more time-in-bed than during working days. The MANOVA showed that Brazilians and Swedes differed significantly in behaviours during working (p <  0.001, ηp2 = 0.36) and non-working days (p <  0.001, ηp2 = 0.20). Brazilian workers spent significantly more time in SED relative to being active, less time in short relative to long bouts in SED, and more time in LPA relative to MVPA, both during workdays and non-workdays. Sensitivity analyses only on data from days when participants worked from home showed similar results. CONCLUSIONS: During the COVID-19 pandemic Brazilian office workers were more sedentary and less active than Swedish workers, both during working and non-working days. Whether this relates to the perception or interpretation of restrictions being different or to differences present even before the pandemic is not clear, and we encourage further research to resolve this important issue.

Cook and Move for Your Life: A pilot study of an online intervention to improve diet and physical activity among breast cancer survivors

Purpose: The Cook & Move for Your Life randomized pilot study assessed the feasibility and relative efficacy of two dose levels of a remotely-delivered diet and physical activity (PA) intervention for breast cancer (BC) survivors. Methods: Women with a history of stage 0-III BC who were >60 days post-treatment, ate <5 servings per day of fruits/vegetables or engaged in <150 minutes per week of moderate to vigorous physical activity (MVPA), and had smartphone or computer access were enrolled. Participants were randomized to receive one of two doses of an online diet and PA didactic and experiential program, with outcomes measured at 6 months. The low-dose arm received a single 2-hour Zoom session delivered by a dietitian, a chef, a culinary educator, and an exercise physiologist;the high-dose arm received 12 2-hour Zoom sessions over 6 months. All participants received weekly motivational text messages, a Fitbit to self-monitor PA, and study website access. The primary objective was to evaluate overall feasibility based on accrual, adherence, and retention. Prespecified feasibility endpoints were 75% retention at 6 months and 60% of high-dose arm participants attending at least 8 of the 12 sessions. Secondary objectives were to compare high vs. low dose intervention effects on 6-month changes in fruit/vegetable servings per day (24-hour dietary recall), MVPA minutes per week (accelerometry), and blood and stool biomarkers.Results: From December 2019 to January 2021, 74 women were accrued. On average, women were 57.9 years old, 4.8 years post-diagnosis, with body mass index of 29.1 kg/m2 . Most were nonHispanic white (89.2%), 51.4% were diagnosed at stage I, and 40.5% were on endocrine therapy. Questionnaire and biospecimen data collection at 6-months were completed for 93.2% and 83.8% of the sample, respectively. In the low-dose arm (n=36), 94.4% of participants attended the single class, while in the high-dose arm (n=38) 84.2% of participants attended at least 8 of the 12 sessions live or via video archived on the website (mean 9.4 sessions). On average over the 6-month intervention period, participants responded to 71.5% of the text messages, 73.0% wore their Fitbit device ≥50% of the time, and 77.0% accessed the study website. Mean vegetable intake increased by 1 serving per day among women in the high-dose arm and decreased slightly among women in the low-dose arm (P=0.03). Changes in fruit/vegetable intake and MVPA varied little by arm. Blood and stool biomarker analyses are ongoing. Conclusion: We successfully conducted a remotely-delivered diet and PA intervention for BC survivors with high accrual, adherence, and retention during the COVID-19 pandemic. Women in the high-dose arm increased vegetable intake relative to the low-dose arm. Future research will refine and test the intervention in a larger and more diverse study population.

Cardiac Effort Provides a Reproducible Remote Assessment of 6-Minute Walk Test

Rationale: 'Cardiac Effort' (CE), the total number of heart beats used during the 6-minute walk test (6MWT) divided by walk distance (beats/m), improves reproducibility in the 6MWT and correlates with right ventricular function in pulmonary arterial hypertension (PAH). The SARS-CoV-2 pandemic made in-office 6MWT challenging. We aimed to determine 1) whether a chestbased accelerometer could estimate 6MWT distance in the clinic and remotely;2) the reproducibility of CE measured during a remote 6MWT;and 3) the safety of remote 6MWT. We also compared measures of heart rate (HR) derived from electrocardiogram (ECG) and wrist-based photoplethysmography (PPG) during the 6MWT in PAH. Methods: This was a singlecenter, prospective observational study with IRB approval completed October 2020-April 2021. Group 1 PAH subjects on stable therapy for >90 days completed 4-6 total 6MWT during a 2 week period to assess reproducibility;we anticipated no clinical change during this short interval. The first and last 6MWT were performed in the clinic;2-4 remote 6MWT were completed at participant's discretion. Participants did not wear masks but did wear the MC10 Biostamp nPoint sensors to measure ECG HR and accelerometry. Two blinded readers estimated 6MWT distance using raw accelerometry data. We measured PPG HR with a wrist Nonin 3150 pulse oximeter during clinic 6MWT only. Averages of clinic variables and remote variables were used for paired Student's t test, Bland-Altman Plot, or Pearson correlation. Results: We enrolled 20 participants: 80% female;60% connective tissue disease;and 65% on initial combination therapy with ambrisentan and tadalafil. There was a wide range in baseline, clinicperformed 6MWT distance (220 -570 m). The median length of the remote 'hallway' was 40 ft. For clinic walks, there was 0.10% average difference between the directly observed and Biostamp accelerometry-estimated 6MWT distance with a strong correlation of r=0.99, p<0.0001 (figure 1). The 6MWT distance estimated using Biostamp in the clinic was greater than what was estimated remotely, 405 m vs. 389 m, p=0.007. There was no clear difference between clinic or remote CE, 1.83 beats/m vs 1.93 beats/m, p=0.14, or Borg Dyspnea Index, 3.5 vs 3.4, p=0.35. There were no safety concerns. PPG undercounted total HR expenditure during 6MWT compared to Biostamp (629 vs 719, p<0.0001). Conclusion: Remote 6MWT was feasible, appeared safe, and 6MWT distance was shorter than clinic distance. CE calculated by ECG HR and accelerometer-estimated distance provides a reproducible remote assessment of exercise tolerance, comparable to the clinic measured value. (Figure Presented).

Accelerometry Data Delineate Phases of Recovery and Supplement Patient-Reported Outcome Measures Following Lumbar Laminectomy.

BACKGROUND: Patient-reported outcome measures (PROMs) are traditionally used to track recovery of patients after spine surgery. Wearable accelerometers have adjunctive value because of the continuous, granular, and objective data they provide. We conducted a prospective study of lumbar laminectomy patients to determine if time-series data from wearable accelerometers could delineate phases of recovery and compare accelerometry data to PROMs during recovery tracking. METHODS: Patients with lumbar stenosis for whom lumbar laminectomy was indicated were prospectively recruited. Subjects wore accelerometers that recorded their daily step counts from at least 1 week preoperatively to 6 months postoperatively. Subjects completed the Oswestry Disability Index and the 12-Item Short Form Health Survey preoperatively and at 2 weeks, 1 month, 3 months, and 6 months postoperatively. Daily aggregate median steps and individual visit-specific median steps were calculated. The Pruned Linear Exact Time method was used to segment aggregate median steps into distinct phases. Associations between visit-specific median steps and PROMs were identified using Spearman rank correlation. RESULTS: Segmentation analysis revealed 3 distinct postoperative phases: step counts rapidly increased for the first 40 days postoperatively (acute healing), then gained more slowly for the next 90 days (recovery), and finally plateaued at preoperative levels (stabilization). Visit-specific median steps were significantly correlated with PROMs throughout the postoperative period. PROMs significantly exceeded baseline at 6 months postoperatively, while step counts did not (all P < 0.05). CONCLUSIONS: Continuous data from accelerometers allowed for identification of 3 distinct stages of postoperative recovery after lumbar laminectomy. PROMs remain necessary to capture subjective elements of recovery.

Factors That Influence Physical Activity in Hospitalized Patients with Dementia

Introduction: Despite current recommendations, hospitalized older adults, particularly those with dementia, continue to spend little time engaged in physical activity when hospitalized. The purpose of this study was to 1) describe activity among hospitalized older adults with dementia and 2) test the association between specific factors (age, gender, race, cognitive status, comorbidities, baseline function, quality of care interactions, admission diagnosis, and hospital setting) and their physical activity. Methods: This was a descriptive study utilizing baseline data on the first 155 participants of a randomized clinical trial testing the impact of Function Focused Care for Acute Care using the Evidence Integration Triangle (FFC-AC-EIT). This study's major outcome variable of physical activity was based on accelerometry data (MotionWatch8) over the first 24 hours of admission. Three regression models were tested using linear regression and the stepwise approach. Results: The 155 participants had a mean age of 83.5 years old, were 67.7% female, and 65.2% white. The participants spent an average of 1.3% of time in vigorous activity, 3.9% of time in moderate activity, 14.7% of time in low activity, and 80.1% of time in sedentary activity during the first 24 hours of hospitalization. Less cognitive impairment was associated with greater moderate activity (b=-93.408, p=.007) and better baseline mobility was associated with greater low activity (b=-949.453, p=.049). Alternatively, we found that higher age (b=189.350, p=.047), worse baseline mobility (b=2371.364, p=0.004), and non-white race (b=6705.916, p=<0.001) were associated with sedentary behavior. The examined factors for the moderate activity, low activity, and sedentary behavior models only explained 15%, 8%, and 22% of the variance respectively. Conclusions: The findings from this study support the limited time spent in activity for older adults with dementia when hospitalized. This research highlights patient profiles that are particularly vulnerable to sedentary behavior in the hospital and should be identified for activity interventions. Future research should consider other factors such as providers' racial bias, COVID-19 related health professional staffing shortages and burn out, and patient motivation.

Feasibility of Smartphone-Based Physical Activity Tele-Coaching in Lung Transplant Recipients;an Interim Analysis

Purpose: The COVID-19 pandemic has increased the demand for tele-medicine, particularly for lung transplant (LTX) recipients who are immunosuppressed and often live far from transplant centres. We report the feasibility of a 3-month semi-automated tele-coaching intervention in this population. Methods: The intervention consists of a pedometer and smartphone app, allowing transmission of activity data to a platform (Linkcare v2.7) that provides feedback, activity goals, education and contact with the researcher as required. Remote assessment pre- and post-intervention included patient acceptability using a project specific questionnaire, physical activity using accelerometry (Actigraph GT3X), HADS and the SF-36 questionnaire. Results: So far, all eligible patients approached were willing to be randomised to the intervention or usual care (n=14;COPD=4, ILD=7;CF=1;PH=2). For the intervention, usage of the pedometer was excellent, with patients wearing it for 6.9±0.1 days/week and rating the pedometer and telephone contact (9±2 out of 10) as the most vital aspects. Patient feedback has been positive, with 80% of patients responding that they ‘liked’ taking part and that it ‘helped them a lot’ to increase their activity levels. Daily steps and VMU are presented in Figure 1 and SF-36 scores in Figure 2. There were no changes in HADS scores between groups. Conclusion: Tele-coaching appears feasible in LTX recipients, with patients showing excellent adherence and providing positive feedback after 3 months. This is promising, with the on-going need to develop and evaluate ways of supporting patients remotely.

Technology outcome measures in neuromuscular disorders: A systematic review.

BACKGROUND AND PURPOSE: Portable and wearable devices can monitor a number of physical performances and lately have been applied to patients with neuromuscular disorders (NMDs). METHODS: We performed a systematic search of literature databases following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) principles, including all studies reporting the use of technological devices for motor function assessment in NMDs from 2000 to 2021. We also summarized the evidence on measurement properties (validity, reliability, responsiveness) of the analyzed technological outcome measures. RESULTS: One hundred studies fulfilled the selection criteria, most of them published in the past 10 years. We defined four categories that gathered similar technologies: gait analysis tools, for clinical assessment of pace and posture; continuous monitoring of physical activity with inertial sensors, which allow "unsupervised" activity assessment; upper limb evaluation tools, including Kinect-based outcome measures to assess the reachable workspace; and new muscle strength assessment tools, such as Myotools. Inertial sensors have the evident advantage of being applied in the "in-home" setting, which has become especially appealing during the COVID-19 pandemic, although poor evidence from psychometric property assessment and results of the analyzed studies may limit their research application. Both Kinect-based outcome measures and Myotools have already been validated in multicenter studies and different NMDs, showing excellent characteristics for application in clinical trials. CONCLUSIONS: This overview is intended to raise awareness on the potential of the different technology outcome measures in the neuromuscular field and to be an informative source for the design of future clinical trials, particularly in the era of telemedicine.

The Impact of COVID-19 on Preschool-Aged Children's Movement Behaviors in Hong Kong: A Longitudinal Analysis of Accelerometer-Measured Data.

During the COVID-19 pandemic, many preschool-aged children were forced to remain indoors due to social distancing measures and school closures. In this study, we examined how children's movement behaviors (sedentary behaviors, physical activity, and sleep) were affected by the pandemic. Children's (N = 25, age = 4.4 years, SD = 0.3) movement behaviors were measured before and after the COVID outbreak, respectively. Data collected using accelerometers were analyzed using compositional data analyses. A significant change in the overall time-use composition (F = 5.89, p = 0.002) was found. Results suggested that children spent more time sleeping (8% increase) and in moderate-to-vigorous physical activity (16% increase), with less time spent in sedentary behaviors (9% decrease). However, parent reports suggested that children were less active and had more screen time. In conclusion, the current evidence suggests that children's physical activity is not negatively impacted by the pandemic. However, the continuous surveillance of movement behaviors of young children during the pandemic is needed.

Changes in physical activity during the initial stages of the COVID-19 pandemic.

INTRODUCTION: The COVID-19 pandemic response limited access to many traditional forms of physical activity (PA). Purpose:To assess changes in objectively measured PAofUniversity staff during the initial stageofthe COVID-19 pandemic. METHODS: We implemented a repeated measures natural experiment design. PA data (walking distance, steps∙d#x2D;1, and Moderate#x2D;to#x2D;Vigorous PA (MVPA) time) from commercial grade triaxial accelerometers were collected from employees (N#x3D;625) of a large, public university in the southeast United States during the months of Jan#x2D;May in calendar years 2019 and 2020. RESULTS: Walking distance (6#x2D;9#x25;, p#x3C;0.001) and steps∙d#x2D;1(7#x2D;11#x25;, p#x3C;0.001) were lower during April and May 2020 compared to 2019. However, MVPA time was not significantly different among calendar years for the months of March#x2D;May. Steps∙d#x2D;1significantly decreased after WHO's worldwide pandemic declaration (10,348#xB1;171 v. 9551#xB1;156 steps∙d#x2D;1, p#x3C;0.001) and campus closure (10,100#xB1;160 v. 9,186#xB1;167 steps∙d#x2D;1, p#x3C;0.001). Conversely, steps∙d#x2D;1significantly increased after implementation of the state's "Healthy at Home" order (9,693#xB1;177 vs. 10,156#xB1;185 steps∙d#x2D;1, p#x3C;0.001). CONCLUSION: A decrease in daily steps, but not MVPA, suggests increased sedentary behavior, not reduced participation in exercise, during the early stages of the COVID#x2D;19 pandemic. Specific pandemic response policies may positively or negatively affect PA and sedentary behavior.

Intensity Matters for Musculoskeletal Health: A Cross-Sectional Study on Movement Behaviors of Older Adults from High-Income Scottish and Low-Income South African Communities.

This study aimed to investigate differences in physical activity (PA) patterns and the associations between objectively measured 24-h movement behaviors and musculoskeletal measures (muscle strength, muscle mass, physical performance, and bone mineral density) in a high-income and a low-income community. This cross-sectional study recruited independent living older adults aged 60-85 years from high-income Scottish (n = 150) and low-income South African (n = 138) settings. Participants completed demographic and health questionnaires, and testing included body composition and bone mineral density (dual energy X-ray absorptiometry), physical performance (grip strength, gait speed), and PA (accelerometry). Participants accumulated similar amounts of weekly total PA, however, the Scottish cohort engaged in more moderate-to-vigorous intensity PA (MVPA) and sedentary behavior (SB), while the South African cohort spent more time sleeping and in light intensity PA (LPA). From compositional data analysis, more time spent in MVPA relative to the other movement behaviors was positively associated with higher muscle mass (p < 0.001) and strength (p = 0.001) in the Scottish cohort. Conversely, more time spent in MVPA was associated with faster gait speed (p < 0.001) and greater hip bone mineral density (p = 0.011) in the South African cohort. Our findings confirm the beneficial role of MVPA in both high- and low-income cohorts, however, the relationship MVPA had with components of musculoskeletal health in older adults differed between settings.

Impact of the COVID-19 pandemic on elementary schoolers' physical activity, sleep, screen time and diet: A quasi-experimental interrupted time series study.

BACKGROUND: COVID-19 school closures pose a threat to children's wellbeing, but no COVID-19-related studies have assessed children's behaviours over multiple years . OBJECTIVE: To examine children's obesogenic behaviours during spring and summer of the COVID-19 pandemic compared to previous data collected from the same children during the same calendar period in the 2 years prior. METHODS: Physical activity and sleep data were collected via Fitbit Charge-2 in 231 children (7-12 years) over 6 weeks during spring and summer over 3 years. Parents reported their child's screen time and dietary intake via a survey on 2-3 random days/week. RESULTS: Children's behaviours worsened at a greater rate following the pandemic onset compared to pre-pandemic trends. During pandemic spring, sedentary behaviour increased (+79 min; 95% CI = 60.6, 97.1) and MVPA decreased (-10 min, 95% CI = -18.2, -1.1) compared to change in previous springs (2018-2019). Sleep timing shifted later (+124 min; 95% CI = 112.9, 135.5). Screen time (+97 min, 95% CI = 79.0, 115.4) and dietary intake increased (healthy: +0.3 foods, 95% CI = 0.2, 0.5; unhealthy: +1.2 foods, 95% CI = 1.0, 1.5). Similar patterns were observed during summer. CONCLUSIONS: Compared to pre-pandemic measures, children's PA, sedentary behaviour, sleep, screen time, and diet were adversely altered during the COVID-19 pandemic. This may ultimately exacerbate childhood obesity.

Physical activity behaviour and screen time in Dutch children during the COVID-19 pandemic: Pre-, during- and post-school closures.

BACKGROUND: Measures during the COVID-19 pandemic, including the closure of schools and sports facilities, may have lasting impact on the physical activity (PA) of children that persists for a long time. OBJECTIVE: To investigate the effect of COVID-19 measures on screen time and PA in Dutch children pre-, during- and post-school closures. METHODS: In cohort A (n = 102, 10.5 ± 3.6 years, 42.4% boys), data on PA and screen time during the lockdown were collected using a questionnaire. In cohort B (n = 131, 10.2 ± 0.9 years, 43.5% boys), data on PA and screen time were collected using a questionnaire and accelerometry 1 year before and after school closure. RESULTS: In cohort A, 62% reported less total PA. Self-reported screen time on week days increased 34 ± 105 min/d during the lockdown. In cohort B, sedentary time as measured by accelerometry, increased by 45 ± 67 min/d and only 20% reached PA levels of 60 min/d compared to 64% in May 2019. Self-reported screen time increased by 59 ± 112 min/d and 62 ± 130 min/d during week and weekend days, respectively. CONCLUSIONS: Children were less physically active, and screen time was higher during and after the school closures due to the COVID-19 lockdown. This is alarming as an active lifestyle in children is crucial in preventing chronic diseases such as obesity.