The sedentary behavior reduction in pregnancy intervention (SPRING) pilot and feasibility randomized trial.

Pregnant individuals rarely achieve moderate-to-vigorous intensity physical activity recommendations.Purpose The sedentary behavior reduction in pregnancy intervention (SPRING) pilot and feasibility randomized trial aimed to demonstrate feasibility, acceptability, and initial efficacy of a lower intensity intervention targeting reduced sedentary behavior and increased standing and steps.Methods First trimester pregnant individuals at risk for high sedentary behavior and adverse pregnancy outcomes (APO) were randomized 2:1 to a multi-component sedentary behavior reduction intervention or no-contact control. Intervention components included biweekly remote health coaching, wearable activity monitor, height-adjustable workstation, and a private Facebook group. Evidence-based behavioral targets included sedentary time < 9 h/day, increasing standing by 2-3 h/day, and ≥ 7500 steps/day. Participants completed all-remote assessments (baseline, second trimester, third trimester) of sedentary behavior and activity (thigh-worn activPAL) along with exploratory pregnancy health outcomes abstracted from medical records. Intervention effects vs. control were evaluated using generalized mixed models and an intention-to-treat approach. Intervention participants also provided feedback on perceived benefits and acceptability.Results Participants (34 intervention; 17 control) had mean age 32 years, were 83% White, with mean pre-pregnancy BMI 28 kg/m2. Retention was high (90% and 83% at second and third trimester follow-up visits). Intervention participants decreased sedentary time (-0.84 h/day, p = 0.019) and increased standing (+0.77 h/day, p = 0.003), but did not increase steps/day (+710, p = 0.257) compared to controls. Intervention participants reported many perceived benefits and identified the wearable, height-adjustable workstation, and behavioral lessons as most useful.Conclusion For pregnant individuals at risk for high sedentary behavior and APOs, a sedentary behavior reduction intervention is feasible, acceptable, and may offer a viable alternative to more intense physical activity recommendations during pregnancy. Further testing in a fully powered clinical trial is warranted.Trial registration NCT05093842 on clinicaltrials.gov.

Similarities and differences in factors associated with high and low sedentary behavior after stroke: a mixed methods study.

PURPOSE: To identify similarities and differences in factors affecting activity engagement between adults with stroke who are more and less sedentary. MATERIALS AND METHODS: Data were pooled from two studies of adults with stroke (N = 36). Sedentary time was measured activPAL micro3. Participants completed activPAL interviews, which were analyzed using framework analysis. Participants were stratified into more and less sedentary groups based on activPAL data. Between-group similarities and differences were identified. RESULTS: Adults with stroke (mean [SD] age = 65.8 [13.6] years, stroke chronicity = 40.5 [SD = 38.3] months, 36.1% female) were more sedentary (785.5 [64.7] sedentary minutes/day) and less sedentary (583.6 [87.4] sedentary minutes/day). Those who were more sedentary: engaged in basic activities of daily living, avoided activities, received assistance from other people, and did not use strategies to overcome barriers. Those who were less sedentary: engaged in instrumental and community activities, embraced new strategies, did activities with other people, and used strategies to overcome environmental barriers. CONCLUSIONS: Factors affecting activity engagement differed between people who are more and less sedentary. Interventions that aim to reduce post-stroke sedentary behavior should consider the: (1) types of activities, (2) role of other people, and (2) application of strategies to overcome activity and environment-related barriers.

People with lower levels of post-stroke sedentary behavior engaged in instrumental and community activities, relative to those with higher levels who primarily engaged in basic activities of daily living.Applying models of social support that emphasize doing with rather than doing for may be important for facilitating non-sedentary lifestyles.Facilitating the use of strategies to overcome environmental barriers to activities may be an important aspect of facilitating non-sedentary lifestyles.

Study Design and Protocol of the Multisite Pregnancy 24/7 Cohort Study.

Hypertensive disorders of pregnancy and other adverse pregnancy outcomes (APOs) are associated with an increased risk of future maternal cardiovascular disease. Physical activity during pregnancy reduces the risk of these APOs, yet few meet physical activity guidelines during pregnancy. Little is known about the role of sedentary behavior or sleep in APOs, a critical gap in knowledge given these behaviors comprise the majority of a 24-hour day. To address this knowledge gap, the Pregnancy 24/7 cohort study (2020-2025) uses 2 devices for 24-hour activity assessment in each trimester of pregnancy to examine associations of sedentary behavior, sleep, and the 24-hour activity cycle (composition of sedentary behavior, physical activity, and sleep) with hypertensive disorders and other APOs. Participants (n = 500) are recruited from the University of Iowa, University of Pittsburgh, and West Virginia University in early pregnancy and followed through delivery. The activPAL3 micro and Actiwatch Spectrum Plus are worn in each trimester for 7 days of 24-hour wear to assess the 24-hour activity cycle. APOs are abstracted from medical charts. This study will provide critical data to fuel future research examining how modifying the 24-hour activity cycle in pregnancy can improve maternal health.

Associations of physical and social workplace characteristics with movement behaviors at work.

Introduction/Purpose: Sedentary behavior (SB) is common in desk-based work and prolonged periods of SB are associated with negative health outcomes. This study assessed associations between workplace characteristics and setting and movement patterns during working hours. Methods: This secondary analysis used baseline data from the Reducing Sedentary Behavior to Decrease Blood Pressure (RESET BP) clinical trial which enrolled inactive, desk-based workers with elevated blood pressure (n=271; mean age: 45.3±11.6 years; body mass index (BMI): 30.66±7.1 kg/m2; 59.4% women). Physical and social workplace characteristics were assessed by a study-developed questionnaire and the Office Environment and Sitting Scale (OFFESS). Participants also wore an activPAL activity monitor for 7 days and reported working hours in a diary to measure SB and physical activity (PA) specifically while working. Linear regression was used to analyze cross-sectional associations between workplace characteristics and SB and PA. A stratified analysis was also conducted to assess associations among home-based and in-office desk workers separately. Analyses were adjusted for age, gender, BMI, and work wear time. Results: Participants spent 77% of working hours in SB. Public vs. private offices, working in-office vs. at home, higher local connectivity, and greater overall connectedness were associated with lower SB and/or greater PA (all p<0.05). Higher frequency of face-to-face interactions, and greater visibility and proximity to co-workers was associated with less SB and more PA (all p<0.05). For example, home-based workers had more total SB (+17.2±8.4 mins/day), more SB bouts ≥30 mins (+39.1±12.8 mins/day), and less steps (695±201 steps/day) than in-office employees. Stratification by office setting revealed differences in associations between SB and PA and workplace characteristics. Conclusions: More public, open spaces with more social interactions and physical walkways could improve SB and PA patterns during work. Home-based workers had more SB, less PA, and unique associations of these activities with workplace characteristics, suggesting a need for tailored interventions.

Protocol for a study on Sitting with Interruption and Whole-Body Cardiovascular Health (SWITCH) in middle-aged adults.

BACKGROUND: Sedentary behavior (SB) is a biologically distinct yet understudied cardiovascular disease risk (CVD) factor. However, specific public health policy regarding the optimal strategy for SB interruption is unavailable. This paper outlines the protocol for part I of the Sitting with Interruption and Whole-Body Cardiovascular Health (SWITCH) study, including the rationale, objectives, methodology, and next steps. We additionally detail practical considerations that went into the development of the NIH R01 grant supporting this research. METHODS: Healthy men and women (n = 56, aged 36-55) who are inactive (<90 min/wk. of moderate-to-vigorous intensity physical activities for past 3 months) and sedentary (sitting for >8 h/day), will be recruited for this randomized crossover trial. Specifically, participants will complete the following 4-h conditions: (i) SB with once/h 5 min walk break; (ii) SB with once/h 15 min stand break; (iii) SB with twice/h breaks (alternating 5 min walk and 15 min stand); and (iv) SB with no breaks (i.e., control). Focus group discussions will refine our socioecological SB reduction model. RESULTS: The primary outcome will be change in aortic arterial stiffness (i.e., pulse wave velocity; PWV, m/s) for each substitution strategy relative to the control (SB with no breaks) condition. CONCLUSIONS: The outcomes from this study will facilitate the design of a subsequent randomized controlled trial to test a mechanism-informed, feasible SB-reduction intervention and support the development of SB policy.

Isotemporal Associations of Device-Measured Sedentary Time and Physical Activity with Cardiac-Autonomic Regulation in Previously Pregnant Women.

BACKGROUND: High sedentary time (ST) and low physical activity may increase cardiovascular risk, potentially though cardiac-autonomic dysregulation. This study investigated associations of statistically exchanging device-measured ST and physical activity with measures of cardiac-autonomic regulation in previously pregnant women. METHOD: This cross-sectional, secondary analysis included 286 women (age = 32.6 ± 5.7 years; 68% white) measured 7-15 years after delivery. ST and light (LPA), moderate (MPA), vigorous (VPA), and moderate-to-vigorous (MVPA) intensity physical activity were measured by ActiGraph GT3X. ST was further partitioned into long (≥ 30 min) and short (< 30 min) bouts. MVPA was also partitioned into long (≥ 10 min) and short (< 10 min) bouts. Cardiac-autonomic regulation was assessed by heart rate variability (HRV) (resting heart rate, natural log transformed standard deviation of normal R-R intervals [lnSDNN], natural log-transformed root mean square of successive differences [lnRMSSD]) from a 5-min seated ECG. Progressive isotemporal substitution models adjusted for confounders. Sensitivity analyses removed women with related underlying medical conditions and who did not meet respiration rate criteria. RESULTS: Initial analyses found no significant associations with HRV when exchanging 30 min of ST and physical activity (p > 0.05). Yet, replacing long- and short-bout ST with 30 min of long-bout MVPA yielded significantly higher (healthier) lnRMSSD (B = 0.063 ± 0.030 and B = 0.056 ± 0.027, respectively; both p < 0.05). Sensitivity analyses strengthened these associations and yielded further associations of higher lnSDNN and lnRMSSD when replacing 30 min of short-bout MVPA with equivalent amounts of long-bout MVPA (B = 0.074 ± 0.037 and B = 0.091 ± 0.046, respectively). CONCLUSION: Replacing ST with long-bout MVPA is a potential strategy to improve cardiac-autonomic function in previously pregnant women.

Utility of Estimated Pulse Wave Velocity for Tracking the Arterial Response to Prolonged Sitting.

Background: Arterial stiffness, measured by pulse wave velocity (PWV), is a purported mechanism linking sedentary behavior to cardiovascular disease. This secondary analysis compared associations between measured carotid−femoral PWV (cfPWV) and carotid−radial (crPWV) responses to an acute bout of prolonged sitting with mathematically estimated cfPWV (ePWV). Methods: Overweight/obese adults with elevated blood pressure were enrolled (n = 25; 42 ± 12 yrs; 64% males). Participants performed an 8 h simulated workday of mostly sitting. cfPWV and crPWV were measured while supine in the morning, midday, and afternoon. ePWV was calculated at the same timepoints using age and seated mean arterial pressure (MAP). Pearson correlation coefficients associated ePWV with cfPWV and crPWV. Generalized linear models separately examined the effects of time on cfPWV, crPWV, and ePWV. Results: ePWV significantly associated with cfPWV and crPWV (r = 0.69 and 0.55, respectively; p < 0.05) in the morning (baseline). cfPWV significantly increased over time (ß = 0.52 ± 0.20 and 0.48 ± 0.21 with and without MAP adjustment, respectively; p < 0.05). In contrast, ePWV and crPWV did not significantly increase overtime (ß = 0.14 ± 0.09 and 0.25 ± 0.23, respectively; p > 0.05). Conclusions: Our results suggest that, although ePWV is associated with cfPWV and crPWV at a fixed timepoint, ePWV responds differently to prolonged sitting and likely does not capture the same acute vascular responses.

Concurrent Agreement Between ActiGraph and activPAL for Measuring Physical Activity in Pregnant Women and Office Workers.

Introduction: Current best practice for objective measurement of sedentary behavior and moderate-to-vigorous intensity physical activity (MVPA) requires two separate devices. This study assessed concurrent agreement between the ActiGraph GT3X and the activPAL3 micro for measuring MVPA to determine if activPAL can accurately measure MVPA in addition to its known capacity to measure sedentary behavior. Methods: Forty participants from two studies, including pregnant women (n = 20) and desk workers (n = 20), provided objective measurement of MVPA from waist-worn ActiGraph GT3X and thigh-worn activPAL micro3. MVPA from the GT3X was compared with MVPA from the activPAL using metabolic equivalents of task (MET)- and step-based data across three epochs. Intraclass correlation coefficient and Bland-Altman analyses, overall and by study sample, compared MVPA minutes per day across methods. Results: Mean estimates of activPAL MVPA ranged from 22.7 to 35.2 (MET based) and 19.7 to 25.8 (step based) minutes per day, compared with 31.4 min/day (GT3X). MET-based MVPA had high agreement with GT3X, intraclass correlation coefficient ranging from .831 to .875. Bland-Altman analyses revealed minimal bias between 15- and 30-s MET-based MVPA and GT3X MVPA (-3.77 to 8.63 min/day, p > .10) but with wide limits of agreement (greater than ±27 min). Step-based MVPA had moderate to high agreement (intraclass correlation coefficient: .681-.810), but consistently underestimated GT3X MVPA (bias: 5.62-11.74 min/day, p < .02). For all methods, activPAL appears to better estimate GT3X at lower quantities of MVPA. Results were similar when repeated separately by pregnant women and desk workers. Conclusion: activPAL can measure MVPA in addition to sedentary behavior, providing an option for concurrent, single device monitoring. MET-based MVPA using 30-s activPAL epochs provided the best estimate of GT3X MVPA in pregnant women and desk workers.

Feasibility, acceptability, and preliminary efficacy of a single-arm, remotely-delivered health coaching intervention to increase physical activity and reduce sedentary behavior during pregnancy.

BACKGROUND: Interventions targeting physical activity and sedentary behavior concurrently in pregnancy may be an ideal strategy to reduce the risk of pregnancy complications. We assessed the feasibility, acceptability, and preliminary efficacy of a single-arm, remotely-delivered health coaching intervention to promote physical activity and reduce sedentary behavior in pregnancy. METHODS: Women (n = 34) between 8 and 12 weeks gestation were recruited to take part in the INcreasing Steps in PREgnancy (INSPiRE) study. Participants were given an activity tracker (Fitbit Inspire) and met virtually with their health coach throughout the second and third trimesters of pregnancy. Feasibility was based on enrollment, retention, and adherence rates. Acceptance was assessed using a process evaluation survey. Intervention efficacy was based on activPAL data obtained at baseline and the end of the second trimester. RESULTS: Feasibility objectives were met, with greater than 70% enrollment, 97% retention, and 99% adherence. All participants reported high levels of satisfaction with the program. ActivPAL data indicated statistically significant increases in daily steps (+ 1715.8 steps/day, Cohen's d = 0.97), stepping time (+ 1.9%, d = 0.75), standing time (+ 2.3%, d = 0.29), and decreases in total sedentary time (- 4.2%, d = 0.43) and sedentary bouts of 30 minutes (- 4.1%, d = 0.36) from baseline to the end of the second trimester, all p < 0.05. Decreases were also observed in sedentary bouts of 60 minutes (- 3.9%, d = 0.40), but this was not statistically significant. CONCLUSIONS: The INSPiRE study demonstrated feasibility, high acceptability, and preliminary efficacy for improving movement behaviors in women during pregnancy, supporting future testing in a randomized controlled trial.

Effect of a 6-month sedentary behavior reduction intervention on well-being and workplace health in desk workers with low back pain.

BACKGROUND: Research suggests reducing sedentary behavior improves low back pain; however, the impact on presenteeism, health, productivity, and sleep in desk workers with chronic low back pain is not known. OBJECTIVE: Evaluate the effect of a sedentary behavior intervention on multiple dimensions of workplace health. METHODS: 24 participants with chronic low back pain and desk jobs were randomized to either a sedentary behavior reduction intervention group or control. Outcomes included a modified Global Physical Activity Questionnaire (GPAQ), the Stanford Presenteeism Scale (SPS), Profile of Mood States (POMS), Health and Work Questionnaire (HWQ), SF-36 Health Survey (SF-36), and Pittsburgh Sleep Quality Index (PSQI). Six-month changes in outcomes were compared across intervention groups using ANCOVA regression, adjusting for baseline values. Cohen's d effect sizes were calculated for outcomes to explain the magnitude of group differences. RESULTS: The intervention group reported 1.5 hours/day less sitting time (p < 0.001) compared to controls at 6 months. SF-36 subscales of energy/fatigue, social functioning, and pain improved, and sleep disturbance was reduced among intervention participants. Productivity, concentration, and presenteeism were unchanged. CONCLUSIONS: A sedentary behavior reduction intervention may improve well-being and workplace health without impacting productivity and concentration in desk workers with chronic low back pain.

Maternal Sedentary Behavior and Physical Activity across Pregnancy and Early Childhood Growth.

Background: Evidence suggests in utero exposures are related to lifespan health of the offspring. Whether maternal activity profile during pregnancy impacts offspring health remains unknown. Methods: This follow-up study recruited mothers with objectively measured sedentary behavior (SED) and moderate-to-vigorous intensity physical activity (MVPA) from a previous cohort study. Maternal activity was analyzed across pregnancy (trajectory groups) and continuously by trimester. Offspring anthropometrics up to 24 months were abstracted from medical records (n = 62). Outcomes included childhood growth rate (incremental rate of BMI z-score change up to 24 months) and rapid growth (increased BMI z-score >0.67 at 12 months). Associations of maternal activity with growth rate were examined using mixed linear models and rapid growth using generalized linear models. Results: Forty percent of participants were in the high SED and 20% in the high MVPA trajectories during pregnancy. Higher SED, across pregnancy [slope (95% confidence interval; CI): 0.080 (0.024-0.061) ΔBMI z-score/month] and in the first trimester [standardized beta; std ß (95% CI): 0.017 (0.007-0.026)], was related to accelerated growth rate. Higher MVPA, in the second and third trimesters, was associated with accelerated growth rate [std ß (95% CI): trimester 2: 0.013 (0.002-0.024) and trimester 3:0.011 (0.003-0.020)] and greater risk of rapid growth [risk ratio (95% CI): trimester 2: 1.25 (1.009-1.555) and trimester 3: 1.25 (1.056-1.475)]. Conclusions: These findings add to growing evidence on the deleterious effects of high SED during pregnancy. The increased risk for accelerated growth with higher MVPA elicits further investigation. Overall, maternal activity profile shows promise as a modifiable behavior to improve intergenerational health.

Association of Physical Activity and Sedentary Time with Cardio-Autonomic Regulation in Women.

Background: Low moderate-to-vigorous-intensity physical activity (MVPA) and high sedentary time (ST) may contribute to cardiovascular disease (CVD) risk in women, perhaps via cardiac autonomic dysregulation. We examined associations of total, leisure, and occupational MVPA and ST with cardiac autonomic regulation in women. Methods: Data were from 522 women (age = 37.7 ± 5.7 years; 59%white) who participated in the follow-up study of the Pregnancy Outcomes and Community Health Study (between 2011 and 2014). MVPA and ST (hours/day) were self-reported using the Modifiable Activity Questionnaire. Cardiac autonomic regulation was assessed by calculating heart rate variability (HRV) indices (resting heart rate, natural logarithm standard deviation of normal R-R intervals; lnSDNN [total variability], natural logarithm root mean square of the successive differences; lnRMSSD [cardiac parasympathetic activity]) with Kubios software from a 5-minute, seated electrocardiogram. Progressive generalized linear models evaluated associations of total, leisure, and occupational MVPA and ST with HRV indices while adjusting for confounders (demographics, health-related factors), and then potential mediators (clinical variables). A final model evaluated the relationship between ST and HRV stratified by MVPA level. Results: Adjusting for confounders, total and leisure MVPA were associated with favorable lnSDNN (B = 0.027 [p = 0.014] and B = 0.074 [p = 0.009], respectively) and lnRMSSD (B = 0.036 [p = 0.015] and B = 0.075 [p = 0.043], respectively). Adjustment for mediators tended to strengthen the observed significant associations. No associations were found between occupational MVPA or any ST measure with HRV indices (p > 0.05). Neither MVPA nor ST were associated with heart rate. When stratified by MVPA level, leisure ST was associated with unfavorable lnRMSSD (B = -0.041, [p = 0.042]) only among women who did not meet leisure MVPA recommendations. Conclusion: Cardiac autonomic dysregulation may be a mechanism through which low leisure MVPA and, among low-active women, high leisure ST contribute to CVD risk among women.

Supporting Physical Activity in Patients and Populations During Life Events and Transitions: A Scientific Statement From the American Heart Association.

Achieving recommended levels of physical activity is important for optimal cardiovascular health and can help reduce cardiovascular disease risk. Emerging evidence suggests that physical activity fluctuates throughout the life course. Some life events and transitions are associated with reductions in physical activity and, potentially, increases in sedentary behavior. The aim of this scientific statement is to first provide an overview of the evidence suggesting changes in physical activity and sedentary behavior across life events and transitions. A second aim is to provide guidance for health care professionals or public health workers to identify changes and promote physical activity during life events and transitions. We offer a novel synthesis of existing data, including evidence suggesting that some subgroups are more likely to change physical activity behaviors in response to life events and transitions. We also review the evidence that sedentary behavior changes across life events and transitions. Tools for health care professionals to assess physical activity using simple questions or wearable devices are described. We provide strategies for health care professionals to express compassion as they ask about life transitions and initiate conversations about physical activity. Last, resources for life phase-specific, tailored physical activity support are included. Future research needs include a better characterization of physical activity and sedentary behavior across life events and transitions in higher-risk subgroups. Development and testing of interventions designed specifically to combat declines in physical activity or increases in sedentary behavior during life events and transitions is needed to establish or maintain healthy levels of these cardiovascular health-promoting behaviors.

Measurement of Barriers, Attitudes, and Expectations for Sitting Less in Pregnancy.

OBJECTIVE: Our objective was to develop, validate, and describe findings from an instrument to measure barriers, attitudes, and outcome expectations of sitting less in pregnant women. METHODS: This validation (sub-study 1) and descriptive study (sub-study 2) evaluated a new questionnaire measuring sedentary time in pregnant women (N=131) in each trimester. RESULTS: In sub-study 1, construct validity was supported by associations between device-measured sedentary time and questionnaire scores. An optimized questionnaire removed infrequently reported and non-correlated items. The original and optimized questionnaires with scoring instructions are provided. In sub-study 2, physical symptoms and work were most commonly reported as major reasons for sitting in pregnancy, followed by leisure, family, and social activities. Some women reported limiting sitting due to boredom/restlessness, to improve energy or health, and to control weight. In the third trimester, some women reported sitting more/less due to pain and encouragement from family, friends, and co-workers. Few women reported household chores or pregnancy risks as reasons to sit, felt sitting was healthy or necessary during pregnancy, or were encouraged to sit by healthcare providers. CONCLUSIONS: The developed questionnaire demonstrated validity and identified barriers to and expectations of sitting less during pregnancy. Prenatal interventions to reduce sitting should address general and pregnancy-specific barriers.

Associations of Sedentary Time with Heart Rate and Heart Rate Variability in Adults: A Systematic Review and Meta-Analysis of Observational Studies.

PURPOSE: To evaluate if sedentary time (ST) is associated with heart rate (HR) and variability (HRV) in adults. METHODS: We systematically searched PubMed and Google Scholar through June 2020. Inclusion criteria were observational design, humans, adults, English language, ST as the exposure, resting HR/HRV as the outcome, and (meta-analysis only) availability of the quantitative association with variability. After qualitative synthesis, meta-analysis used inverse variance heterogeneity models to estimate pooled associations. RESULTS: Thirteen and eight articles met the criteria for the systematic review and meta-analysis, respectively. All studies were cross-sectional and few used gold standard ST or HRV assessment methodology. The qualitative synthesis suggested no associations between ST and HR/HRV. The meta-analysis found a significant association between ST and HR (ß = 0.24 bpm per hour ST; CI: 0.10, 0.37) that was stronger in males (ß = 0.36 bpm per hour ST; CI: 0.19, 0.53). Pooled associations between ST and HRV indices were non-significant (p > 0.05). Substantial heterogeneity was detected. CONCLUSIONS: The limited available evidence suggests an unfavorable but not clinically meaningful association between ST and HR, but no association with HRV. Future longitudinal studies assessing ST with thigh-based monitoring and HRV with electrocardiogram are needed.

Effects of Acute Prolonged Sitting and Interrupting Prolonged Sitting on Heart Rate Variability and Heart Rate in Adults: A Meta-Analysis.

Prolonged sitting increases cardiovascular disease (CVD) risk, however the physiological mechanisms contributing to CVD from acute sitting exposure are not well-understood. Therefore, this study investigated the heart rate (HR) and variability (HRV) responses to prolonged sitting and after interrupting prolonged sitting (e.g., walking). Electronic databases were searched (inception-August 2020) for studies which exposed adults to prolonged (≥1 h) sitting with and/or without interruptions. Twenty-one articles (27 trials, n = 537) met inclusion criteria. Prolonged sitting non-significantly increased HR (weighted mean difference (WMD) = 0 bpm, 95% CI: -2, 3) and HRV (standardized mean difference (SMD) = 0.12, 95% CI: -0.08, 0.33) compared to pre-sitting baseline. Interrupting prolonged sitting yielded a non-significant small increase in HR (WMD = 4 bpm, 95% CI: 0, 7) compared to pre-sitting baseline. Sub-group analyses investigating interrupting prolonged sitting revealed small-to-moderate increases in HR in healthy populations (WMD = 6 bpm, 95% CI: 1, 10) and following walking interruptions (WMD = 7 bpm, 95% CI: 3, 11). In conclusion, prolonged sitting does not significantly affect HR or HRV. However, interrupting prolonged sitting yielded a small non-significant increase in HR, potentially indicative of increased metabolic demand. Further research is needed to investigate poor CVD outcomes via autonomic disruption from prolonged sitting.

Cardiovascular risk and functional burden at midlife: Prospective associations of isotemporal reallocations of accelerometer-measured physical activity and sedentary time in the CARDIA study.

Cardiovascular risk and functional burden, or the accumulation of cardiovascular risk factors coupled with functional decline, may be an important risk state analogy to multimorbidity. We investigated prospective associations of sedentary time (ST), light intensity physical activity (LPA), and moderate to vigorous intensity physical activity (MVPA) with cardiovascular risk and functional burden at midlife. Participants were 1648 adults (mean ± SD age = 45 ± 4 years, 61% female, 39% Black) from Coronary Artery Risk Development in Young Adults (CARDIA) who wore accelerometers in 2005-2006 and 2015-2016. Cardiovascular risk and functional burden was defined as ≥2 cardiovascular risk factors (untreated/uncontrolled hypertension and hypercholesterolemia, type 2 diabetes, reduced kidney function) and/or functional decline conditions (reduced physical functioning and depressive symptoms). Prospective logistic regression models tested single activity, partition, and isotemporal substitution associations of accelerometer-measured ST, LPA, and MVPA with cardiovascular risk and functional burden 10 years later. In isotemporal models of baseline activity, reallocating 24 min of ST to MVPA was associated with 15% lower odds of cardiovascular risk and functional burden (OR: 0.85; CI: 0.75, 0.96). Reallocating 24 min of LPA to MVPA was associated with a 14% lower odds of cardiovascular risk and functional burden (OR: 0.86; CI: 0.75, 0.99). In longitudinal isotemporal models, similar beneficial associations were observed when 10-year increases in MVPA replaced time in ST or LPA. Findings suggest that maintaining an MVPA dose reflecting daily physical activity recommendations in early midlife is associated with lower odds of cardiovascular risk and functional burden later in midlife.

Effects of a personal trainer-led exercise intervention on physical activity, physical function, and quality of life of breast cancer survivors.

PURPOSE: Exercise is important to address physical and emotional effects of breast cancer treatment. This study examines effects of a personal trainer led exercise intervention on physical activity levels, physical function and quality of life (QoL) in breast cancer survivors. METHODS: Women post active breast cancer treatment were recruited from 2015 to 2017, randomized to immediate exercise or wait-list control, and received three personal training sessions for up to 30 weeks. Physical activity and function were assessed by pedometer, and tests of endurance, strength, and flexibility. Self-reported physical activity, physical activity self-efficacy, and QoL were also assessed. RESULTS: 60 women were randomized to immediate intervention (n = 31) or wait-list control (n = 29). Subjects were aged (mean ± SD) 56 ± 10 years. On the endurance test, the exercise group significantly improved (increase of 18 ± 20 steps vs control 9 ± 12 steps) (p = 0.036). On the strength test, the exercise group significantly improved (increase of 4 ± 3 curls vs control 1 ± 3 curls) (p = 0.002). After intervention, change (mean ∆ ± SD) in the FACT-ES physical well-being subscale score was 1 ± 2 in the exercise group and - 1 ± 2 in the control group (p = 0.023). Improvement in Self-efficacy and Physical Activity (SEPA) score was significant with a change (mean ∆ ± SD) of 2 ± 5 for exercise vs 0 ± 5 for control (p = 0.047). The number of steps/day, back scratch test, weight, and self-reported physical activity did not significantly improve with intervention. CONCLUSIONS: The intervention yielded significant improvements in endurance and strength but not physical activity or quality of life. IMPLICATIONS FOR CANCER SURVIVORS: Future efforts to explore feasible ways to support patient's physical activity efforts need to be undertaken.

Generational Status, Language Use, Parental Limit Setting, and Screen Time in US Latinx Children.

Latinx children engage in excessive screen time and are disproportionately affected by obesity. We examined the effect of generational status and language use on screen time in 6- to 11-year-old Latinx children and whether parental limit setting mediated that relationship. Participants included 3127 children (aged 9.2 ± 2.0 years; 54% male) from the 2011-2012 National Survey of Children's Health. Spanish language use was associated with 14.0 more minutes per day of screen time (P = .038); parental limit setting partially mediated this relationship (11.4%). Future research should explore the protective role of parental limit setting in reducing screen time in Latinx children.

Activating Behavior to Reduce Sedentary Behavior After Stroke: A Nonrandomized Pilot Feasibility Study.

IMPORTANCE: Reducing poststroke sedentary behavior is important for reducing recurrent stroke risk, yet interventions to achieve this are scant. OBJECTIVE: To assess the feasibility of, and estimate change in sedentary behavior over time associated with, a behavioral intervention. DESIGN: Single-arm delayed baseline with postintervention and 8-wk follow-up assessment. SETTING: Community based. PARTICIPANTS: Ambulatory, community-dwelling people with chronic stroke and reported ≥6 hr daily sitting time (N = 21). INTERVENTION: Activating Behavior for Lasting Engagement (ABLE) was delivered by an occupational therapist 3×/wk for 4 wk. ABLE involves activity monitoring, activity scheduling, self-assessment, and collaborative problem solving. OUTCOMES AND MEASURES: Feasibility (participant safety, adherence, satisfaction, and reliable intervention delivery) was assessed against preestablished benchmarks. Changes over time in sedentary behavior (assessed with an ActivPAL micro3 device) and participation (Stroke Impact Scale-Participation subscale) were described. RESULTS: ABLE was safe (0 serious adverse events), adhered to (11.95 sessions/participant), and reliably delivered (90.00%-97.50% adherence). Participant satisfaction was unmet (Client Satisfaction Questionnaire-8, M = 28.75, SD = 3.84). ABLE was associated with a mean group reduction in prolonged sitting of 54.95 min (SD = 81.10) at postintervention and 14.08 (SD = 58.95) at follow-up. ABLE was associated with a negligible mean group increase over time in participation at postintervention (M = 1.48%, SD = 8.52) and follow-up (M = 1.33%, SD = 15.38). CONCLUSIONS AND RELEVANCE: The ABLE intervention is feasible and may be associated with within-group reduction in sedentary behavior over time. Further refinement is indicated. WHAT THIS ARTICLE ADDS: The ABLE intervention uses engagement in meaningful daily activities to reduce sedentary behavior after stroke. These findings suggest that ABLE can be delivered safely and consistently. Further research is required to enhance participant satisfaction and determine the effects of ABLE on stroke survivors' sedentary behavior.