Physical activity improves stress load, recovery, and academic performance-related parameters among university students: a longitudinal study on daily level.

BACKGROUND: Physical activity has been proven to be beneficial for physical and psychological health as well as for academic achievement. However, especially university students are insufficiently physically active because of difficulties in time management regarding study, work, and social demands. As they are at a crucial life stage, it is of interest how physical activity affects university students' stress load and recovery as well as their academic performance. METHODS: Student´s behavior during home studying in times of COVID-19 was examined longitudinally on a daily basis during a ten-day study period (N = 57, aged M = 23.5 years, SD = 2.8, studying between the 1st to 13th semester (M = 5.8, SD = 4.1)). Two-level regression models were conducted to predict daily variations in stress load, recovery and perceived academic performance depending on leisure-time physical activity and short physical activity breaks during studying periods. Parameters of the individual home studying behavior were also taken into account as covariates. RESULTS: While physical activity breaks only positively affect stress load (functional stress b = 0.032, p < 0.01) and perceived academic performance (b = 0.121, p < 0.001), leisure-time physical activity affects parameters of stress load (functional stress: b = 0.003, p < 0.001, dysfunctional stress: b = -0.002, p < 0.01), recovery experience (b = -0.003, p < 0.001) and perceived academic performance (b = 0.012, p < 0.001). Home study behavior regarding the number of breaks and longest stretch of time also shows associations with recovery experience and perceived academic performance. CONCLUSIONS: Study results confirm the importance of different physical activities for university students` stress load, recovery experience and perceived academic performance in home studying periods. Universities should promote physical activity to keep their students healthy and capable of performing well in academic study: On the one hand, they can offer opportunities to be physically active in leisure time. On the other hand, they can support physical activity breaks during the learning process and in the immediate location of study.

Effects of prolonged sitting and physical activity breaks on measures of arterial stiffness and cortisol in adolescents.

AIM: In adults, prolonged periods of sitting have been linked to acute negative effects on vascular structure and function. The aim of this study was to evaluate the acute effects of physical activity (PA) breaks during prolonged sitting on arterial stiffness, cortisol and psychological factors in adolescents. METHODS: Adolescents underwent different short (3-min) breaks starting every 20 min, during 80 min of sitting on three separate days. Breaks were (A) social seated breaks (SOC), (B) low-intensity simple resistance activity PA breaks (SRA) and (C) moderate-intensity step-up PA breaks (STEP). The arterial stiffness measures were augmentation index (AIx), AIx@75 and pulse wave velocity (PWV). Cortisol was measured from saliva. Psychological factors were self-reported. RESULTS: Eleven girls and six boys (average age 13.6 ± 0.7 years) participated, with average baseline heart rates of 72 ± 11 bpm, systolic/diastolic blood pressure 111 ± 7/64 ± 6 mmHg and cortisol 10.9 ± 5.8 nmoL/L. PWV, cortisol and psychological factors did not change after any of the conditions. AIx@75 increased significantly (4.9 ± 8.7-9.2 ± 13.2) after the STEP intervention compared with SOC and SRA (time × condition p < 0.05). CONCLUSION: Arterial stiffness increased after prolonged sitting with frequent, short step-up activity breaks. The results indicate potential important intensity-dependent effects of physical activity on vascular regulation in youth.

Breaking up sitting with short frequent or long infrequent physical activity breaks does not lead to compensatory changes in appetite, appetite-regulating hormones or energy intake.

The aim of this study was to determine the appetite-related responses to breaking up prolonged sitting with physical activity bouts differing in frequency and duration among adult females. Fourteen sedentary females aged 34 ± 13 years with a body mass index of 27.1 ± 6.3 kg/m2 (mean ± SD) took part in a randomised crossover trial with three, 7.5 h conditions: (1) uninterrupted sitting (SIT), (2) sitting with short frequent 2-min moderate-intensity walking breaks every 30 min (SHORT-BREAKS), and (3) sitting with longer duration, less frequent 10-min moderate-intensity walking breaks every 170-180 min (LONG-BREAKS). The intensity and total duration of physical activity was matched between the SHORT-BREAKS and LONG-BREAKS conditions. Linear mixed models were used to compare the outcomes between conditions with significance being accepted as p ≤ 0.05. There were no significant between-condition differences in hunger, satisfaction, prospective food consumption or overall appetite area under the curve (AUC) (all p ≥ 0.801). Absolute ad libitum energy intake and relative energy intake (REI) did not differ significantly between conditions (all p ≥ 0.420). Acylated ghrelin and total peptide YY incremental and total AUC did not differ significantly between conditions (all p ≥ 0.388). Yet, there was a medium effect size for the higher acylated ghrelin incremental AUC in SHORT-BREAKS versus SIT (d = 0.61); the reverse was seen for total AUC, which was lower in SHORT-BREAKS versus SIT (d = 0.69). These findings suggest that breaking up sitting does not lead to compensatory changes in appetite, appetite hormones or energy intake regardless of physical activity bout duration and frequency among adult females.

Physical Activity, Confidence, and Social Norms Associated With Teachers' Classroom Physical Activity Break Implementation.

Despite the benefits of classroom physical activity breaks on student health and academic outcomes, more research is needed to understand what factors may be associated with classroom physical activity break implementation, to bolster buy-in from school stakeholders and increase implementation. This quantitative study examined frequency of classroom physical activity break implementation in relation to (1) objectively measured teachers' physical activity and sedentary behaviors, (2) confidence for leading classroom physical activity breaks, (3) social norms (perceptions of other teachers' classroom physical activity break implementation), and (4) teacher- and school-level demographics. In total, 153 classroom teachers in 20 elementary and middle schools completed a survey including classroom physical activity break frequency, confidence, and social norms, one item each, dichotomized (1 = "most/all the time" OR "agree/strongly agree"). Accelerometry assessed total activity and daytime sedentary behavior. Analyses included multilevel binary logistic regression. Teachers were 90% female, 68% White, and 55% in elementary schools. Odds of implementing classroom physical activity breaks were lower among middle school teachers, 14 times greater among those with greater confidence, and over 17 times greater when teachers perceived others frequently implementing classroom physical activity breaks. Teacher activity was not associated with classroom physical activity break implementation. Future interventions to increase classroom physical activity break implementation should focus on increasing teachers' confidence to lead classroom physical activity breaks and creating more buy-in from classroom teachers to enhance each school's culture of health. By enhancing teacher confidence and social norms for implementing classroom physical activity breaks, we may increase school-based physical activity opportunities.

Three weeks of interrupting sitting lowers fasting glucose and glycemic variability, but not glucose tolerance, in free-living women and men with obesity.

We aimed to determine whether interrupting prolonged sitting improves glycemic control and the metabolic profile of free-living adults with obesity. Sixteen sedentary individuals {10 women/6 men; median [interquartile range (IQR)] age 50 (44-53) yr, body mass index (BMI) 32 (32-35.8) kg/m2} were fitted with continuous glucose and activity monitors for 4 wk. After a 1-wk baseline period, participants were randomized into habitual lifestyle (Control) or frequent activity breaks from sitting (FABS) intervention groups. Each day, between 0800 and 1800 h, FABS received smartwatch notifications to break sitting with 3 min of low-to-moderate-intensity physical activity every 30 min. Glycemic control was assessed by oral glucose tolerance test (OGTT) and continuous glucose monitoring. Blood samples and vastus lateralis biopsies were taken for assessment of clinical chemistry and the skeletal muscle lipidome, respectively. Compared with baseline, FABS increased median steps by 744 [IQR (483-951)] and walking time by 10.4 [IQR (2.2-24.6)] min/day. Other indices of activity/sedentary behavior were unchanged. Glucose tolerance and average 24-h glucose curves were also unaffected. However, mean (±SD) fasting glucose levels [-0.34 (±0.37) mmol/L] and daily glucose variation [%CV; -2% (±2.2%)] reduced in FABS, suggesting a modest benefit for glycemic control that was most robust at higher volumes of daily activity. Clinical chemistry and the skeletal muscle lipidome were largely unperturbed, although two long-chain triglycerides increased 1.25-fold in FABS, postintervention. All parameters remained stable in control. Under free-living conditions, FABS lowered fasting glucose and glucose variability. Larger volumes of activity breaks from sitting may be required to promote greater health benefits.NEW & NOTEWORTHY Under free-living conditions, breaking sitting modestly increased activity behavior. Breaking sitting was insufficient to modulate glucose tolerance or the skeletal muscle lipidome. Activity breaks reduced fasting blood glucose levels and daily glucose variation compared with baseline, with a tendency to also decrease fasting LDLc. This intervention may represent the minimal dose for breaking sedentary behavior, with larger volumes of activity possibly required to promote greater health benefits.

Classroom-based physical activity and math performance: Integrated physical activity or not?

AIM: This 8-week intervention examined the effect of two different types of classroom-based physical activity on math performance in elementary school children. METHODS: Students in 4th and 5th grade (N = 560; 32 classes, 9-11 years old) from six schools were assigned to integrated physical activity (Move for Thought [M4T], n = 221), activity break (AB; n = 134) and a control group (n = 205; usual instruction) for eight weeks. Students completed a standardised math test before and after the intervention. Programme fidelity was measured with a teacher daily log, recording the duration and frequency of the physical activity sessions. Linear mixed models were used for the analyses. Grade and gender were explored as moderators. RESULTS: Move for Thought group outperformed AB (p < 0.001, d = 0.44) and control groups (p = 0.013, d = 0.38). However, subgroup analyses showed that these effects were evident only in Grade 4. No gender differences were found. Intervention fidelity showed that the classroom-based physical activities (M4T and AB) were used about every other day, with higher implementation among 4th graders. CONCLUSION: This study indicated that integrating physical activity with mathematics has stronger effects on mathematics than activity breaks and traditional instruction.

Creating a Scalable Physical Activity Breaks Resource Through the Multisensory Multilevel Health Education Model: H.Y.P.E. The Breaks!

Physically active children have lower rates of obesity, diabetes, hypertension, and depression than their inactive counterparts, and further evidence suggests that integrating physical activity breaks into the school day improves children's classroom behavior, fitness, and cognitive functions. The current article focuses on the development and implementation of free, scalable, short activity breaks called H.Y.P.E. The Breaks! (Helping Young People Energize)-a series of 2-, 6-, and 10-minute-long dance and hip-hop-based physical activity videos, which can be used in the classroom or at home. H.Y.P.E. The Breaks! is deconstructed through the lens of the multisensory multilevel health education model, which leverages art, culture, and science in the design and implementation of health programs, and highlights the importance of framing and operationalizing program components across the different behavioral levels of influence of the socioecological model. The article also discusses the uptake of H.Y.P.E. The Breaks! during the COVID-19 (coronavirus disease 2019) pandemic, when major declines in children's physical activity were observed.

Acute effects of breaking up prolonged sedentary time on cardiovascular disease risk markers in adults with paraplegia.

Elevated levels of cardiovascular disease (CVD) risk markers are highly prevalent in people with a spinal cord injury (SCI). Breaking up prolonged sedentary time with short, regular bouts of physical activity can reduce postprandial glucose and lipid levels in able-bodied individuals. The effects in people with paraplegia are unknown. The study aims were to examine the acute postprandial glucose (primary aim), lipid, blood pressure, and psychological responses (secondary aims) to breaking up prolonged sedentary time in individuals with paraplegia. This was a randomized crossover design trial. Fourteen participants with paraplegia (age 51 ± 9 years, trunk fat mass 44.3 ± 7.7%) took part in the following two, 5.5-hour conditions: (1) uninterrupted sedentary time (SED), and (2) sedentary time interrupted with 2 minutes of moderate-intensity arm crank ergometer physical activity every 20 minutes (SED-ACT). Standardized breakfast and lunch test meals were consumed during each condition. The outcomes were compared between conditions using linear mixed models. Glucose area under the curve (AUC) was significantly lower during the lunch postprandial period in SED-ACT vs SED (incremental AUC 1.9 [95% CI 1.0, 2.7) and 3.0 [2.1, 3.9] mmol/L∙2.5 hour, respectively, P = .015, f = 0.34). There were no differences between conditions for the breakfast or total 5.5 hours postprandial periods (P > .05). Positive affect was higher in SED-ACT than SED (P = .001). Breaking up prolonged sedentary time acutely attenuates lunch postprandial glucose and improves positive affect in people with paraplegia. This may have clinical relevance for reducing CVD risk and improving psychological well-being in this population.

Effects of different types of classroom physical activity breaks on children's on-task behaviour, academic achievement and cognition.

AIM: This study examined the effects of different types of classroom physical activity breaks on children's on-task behaviour, academic achievement and cognition. METHODS: Participants were 87 Australian primary school students (mean age 9.11 ± 0.62 years), recruited from one school. Three classes were randomly assigned either to activity breaks only (n = 29), activity breaks and mathematics combined (n = 29), or control conditions involving only mathematical content (n = 29). Students were engaged in five minutes of classroom physical activity breaks, three times per week, for four weeks (divided into two minutes at the beginning of the usual mathematics curriculum lesson and three minutes in the middle of the lesson). Assessments were conducted at baseline and post-test. RESULTS: Significant group-by-time effects were found for on-task behaviour (active engagement: activity breaks and mathematics combined versus control, p ≤ 0.001; activity breaks versus control, p ≤ 0.001; activity breaks and mathematics combined versus activity breaks, p = 0.037; passive engagement: activity breaks and mathematics combined versus control, p ≤ 0.001) and mathematics scores (activity breaks versus control, p = 0.045). CONCLUSION: Physical activity breaks with and without integrated mathematics content were effective in improving children's on-task behaviour and learning scores.

Acute Effects of Interrupting Prolonged Sitting With Intermittent Physical Activity on Blood Pressure in Preadolescent Children.

PURPOSE: To compare the acute effects of intermittent physical activity (PA) across 4 different intensities on blood pressure. METHODS: Thirty children (12 males and 18 females; aged 7-11 y; 33% overweight/obese; 53% nonwhite) completed 4 experimental conditions in random order: 8 hours sitting interrupted with 20, 2-minute low-, moderate-, high-intensity PA breaks, or sedentary screen-time breaks. PA intensity corresponded with 25%, 50%, and 75% of heart rate reserve. Blood pressure was measured during each condition in the morning (0800 h), noon (1200 h), and afternoon (1600 h). RESULTS: There were no significant differences across conditions for systolic blood pressure (SBP; all Ps > .05). There was a significant effect of time with SBP decreasing throughout the day for all conditions (average morning SBP: 106 [1] mm Hg, average noon SBP: 101 [2] mm Hg, average afternoon SBP: 103 [1] mm Hg; P = .01). There were no significant effects of condition or time on diastolic blood pressure (all Ps > .05). CONCLUSION: While sedentary behavior is known to be associated with hypertension in both adults and children, a single bout of prolonged sitting may be insufficient to produce hypertensive effects in otherwise healthy children. Future research should examine the appropriate dose of intermittent PA to accrue hypotensive responses in preadolescent children.

Acute Compensatory Responses to Interrupting Prolonged Sitting With Intermittent Activity in Preadolescent Children.

PURPOSE: The purpose of this study was to compare the effects of intermittent activity performed at varying intensities and of prolonged sitting on physical activity compensation. METHODS: A total of 33 children (14 boys and 19 girls; age 7-11 y; 24% overweight/obese; 61% nonwhite) completed 4 experimental conditions in random order: 8 hours of sitting interrupted with 20 two-minute low-, moderate-, or high-intensity activity breaks or 20 two-minute sedentary computer game breaks. Physical activity energy expenditure (PAEE) was assessed via accelerometry to establish baseline PAEE and throughout each condition day (8-h in-lab PAEE, out-of-lab PAEE, and 3-d postcondition). RESULTS: Compared with baseline PAEE, total daily PAEE was significantly higher during the high-intensity condition day (153 ± 43 kcal, P = .03), unchanged during the low-intensity (-40 ± 23 kcal, P > .05) and moderate-intensity condition days (-11 ± 18 kcal, P > .05), and decreased in response to prolonged sitting (-79 ± 22 kcal, P = .03). There were no significant differences in PAEE 3-day postcondition across conditions (P > .05). CONCLUSION: Despite the varying levels of PAEE accumulated during the 8-hour laboratory conditions, out-of-lab PAEE during each condition day and 3-day postcondition did not change from the baseline. These findings provide preliminary evidence that spontaneous physical activity in children does not change in response to intermittent activity or prolonged sitting.

A randomised controlled trial of multiple periods of outdoor free-play to increase moderate-to-vigorous physical activity among 3 to 6 year old children attending childcare: study protocol.

BACKGROUND: The implementation of physical activity interventions in centre-based childcare services has been recommended to improve child health. This study aims to evaluate the efficacy of scheduling multiple periods of outdoor free play in increasing the time children spend in moderate-to-vigorous physical activity (MVPA) during childcare. METHODS: The study will employ a between group cluster randomised controlled trial design. Fourteen childcare services in the Hunter New England region of New South Wales, Australia, who currently implement a single session of free outdoor play between their core operational hours of 9 am to 3 pm will be recruited into the trial. Childcare services will be randomised to an intervention or a no intervention control group. Childcare services in the intervention group will be supported by an early childhood education specialist to provide three periods of outdoor free play for children between the hours of 9 am to 3 pm. Each period of outdoor free play will be at least 15 min in duration but must equate to their total usual duration of outdoor play. Services in the control group will continue to implement a single period of outdoor play. The primary trial outcome is minutes of time children spend in MVPA whilst in care assessed objectively via accelerometer over 5 days. Outcome assessment will occur at baseline and 3 months post baseline. Generalised Linear Mixed Models (GLMM) under an intention to treat framework will be used to compare differences between groups in the primary trial outcome at follow-up. Sensitivity analysis will be conducted to test assumptions of missing data. Per protocol analysis will be performed using services that implemented the intervention as intended and subgroup analysis undertaken by gender and baseline physical activity levels of children. DISCUSSION: The study tests a simple ecological intervention that has the potential to increase child physical activity in care. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry 12616000347460 . Prospectively registered 17th March 2016.

Motivation and intention to integrate physical activity into daily school life: the JAM World Record event.

Research on the motivation of stakeholders to integrate physical activity into daily school life is limited. The purpose was to examine the motivation of stakeholders to participate in a world record physical activity event and whether motivation was associated with future intention to use activity breaks during the daily school life and future participation in a similar event. After the 2012 JAM (Just-a-Minute) World Record event, 686 adults (591 women; 76.1% participated for children <10 years) completed measures of motivational regulations and future intention to (a) use the activity breaks and (b) participate in the event. High intrinsic motivation and low extrinsic motivation and amotivation for participation in the next event were reported. Hierarchical regression analysis, controlling for age, gender, and occupation, showed that intrinsic forms of motivation positively predicted, whereas amotivation negatively predicted, future intention to participate in the event and use the activity breaks. Multivariate analyses of variance revealed that school-related participants were more intrinsically motivated and intended to use the activity breaks and repeat the event more than those who were not affiliated with a school. Nonschool participants reported higher extrinsic motivation and amotivation than school-related participants.

Effects of physically active maths lessons on children's maths performance and maths-related affective factors: Multi-arm cluster randomized controlled trial.

BACKGROUND: Physical activity (PA) may benefit academic performance, but it is unclear what kind of classroom-based PA is optimal for learning. AIM: We studied the effects of physically active maths lessons on children's maths performance and maths-related effects, and whether gender and previous mathematical or motor skills modify these effects. SAMPLE: A total of 22 volunteered teachers and their pupils with signed consent (N = 397, mean age: 9.3 years, 51% females) participated in a 5-month, teacher-led, multi-arm, cluster-randomized controlled trial. METHODS: The intervention included a PAL group (20 min of physically active learning in each 45-min lesson), a breaks group (two 5-min PA breaks in each 45-min lesson) and a control group (traditional teaching). Maths performance was assessed with a tailored curriculum-based test. Maths-related enjoyment, self-perceptions and anxiety were measured with a self-reported questionnaire. The individual-level intervention effects were tested via covariate-adjusted linear mixed-effect models with school classes serving as random effects. RESULTS: Changes in maths performance or self-perceptions did not differ between the intervention groups. Maths anxiety in learning situations increased in the PAL group (effect .28, 95% CI = .01-.56); there was no change in the other groups. Subgroup analyses suggested that maths anxiety increased in the PAL group among children in the two lowest tertiles of motor skills. It decreased in the highest tertile. Enjoyment decreased in the breaks group among pupils in the lowest motor skill tertile. CONCLUSIONS: Physically active maths lessons did not affect maths performance or self-perceptions but had divergent effects on maths anxiety and enjoyment, depending on motor skills.

In-classroom physical activity breaks program among school children in Sri Lanka: study protocol for a randomized controlled trial.

Background: The problem of sedentary behavior among primary school children is alarming, with numbers gradually increasing worldwide, including Sri Lanka. Physical activity interventions within classroom settings have been acknowledged as a critical strategy to increase students' movement behaviors while enhancing their academic achievement and health. Yet, the busy curriculum and challenging educational demands encourage more sedentary classroom behavior. Hence, this study aims to develop and evaluate an in-classroom physical activity breaks (IcPAB) intervention among fifth graders in Sri Lanka. Methods: The study will adopt a randomized controlled trial (RCT), comprising an in-classroom physical activity breaks program group and a control group to evaluate the effects of IcPAB on academic achievement, movement behaviors and health outcomes. The intervention design is based on the capability (C), opportunity (O) and motivation (M) behavior (B) (COM-B) model. A least 198 fifth graders will be recruited from two schools in Uva province, Sri Lanka. The recruitment process will start in late 2022. Class teachers of the intervention group will implement 5-min activity breaks at least three times a day after completing a training session. The primary variables include mathematics and reading achievement. The secondary variables include physical activity levels, steps count, sedentary behavior, body mass index, aerobic fitness, and perceived stress. Data collection will be implemented at pre-test and post-test, respectively. Intervention fidelity and the process will also be evaluated. Discussion: The IcPAB is designed to prevent pure educational time loss by introducing curriculum-integrated short bouts of physical active breaks into the classroom routine. If the IcPAB is effective, it can (1) improve the mathematics and reading achievement of fifth-grade girls and boys, which is a significant factor determining the performance at the Grade Five National Scholarship Examination in Sri Lanka; (2) improve movement behaviors as well as physical and mental health outcomes among primary school students. Sequentially, the IcPAB will enrich school-based physical activity intervention approaches which can in turn bring academic and health benefits to primary school children in Sri Lanka. Trial registration: The first version of the trial was registered with the ISRCTN registry (Ref: ISRCTN52180050) on 20/07/2022.

Exercise Prescription for Postprandial Glycemic Management.

The detrimental impacts of postprandial hyperglycemia on health are a critical concern, and exercise is recognized a pivotal tool in enhancing glycemic control after a meal. However, current exercise recommendations for managing postprandial glucose levels remain fairly broad and require deeper clarification. This review examines the existing literature aiming to offer a comprehensive guide for exercise prescription to optimize postprandial glycemic management. Specifically, it considers various exercise parameters (i.e., exercise timing, type, intensity, volume, pattern) for crafting exercise prescriptions. Findings predominantly indicate that moderate-intensity exercise initiated shortly after meals may substantially improve glucose response to a meal in healthy individuals and those with type 2 diabetes. Moreover, incorporating short activity breaks throughout the exercise session may provide additional benefits for reducing glucose response.

Short, frequent high-intensity physical activity breaks reduce appetite compared to a continuous moderate-intensity exercise bout.

A single exercise session can affect appetite-regulating hormones and suppress appetite. The effects of short, regular physical activity breaks across the day on appetite are unclear. This study investigated the effects of breaking up sitting with high-intensity physical activity vs a single bout of moderate-intensity exercise and prolonged sitting on appetite control. In this randomised crossover trial, 14 sedentary, inactive adults (7 women) completed 3, 8-h experimental conditions: (i) prolonged sitting (SIT); (ii) 30 min of moderate-intensity exercise followed by prolonged sitting (EX-SIT), and (iii) sitting with 2 min 32 s of high-intensity physical activity every hour (SIT-ACT). Physical activity energy expenditure was matched between EX-SIT and SIT-ACT. Subjective appetite was measured every 30 min with acylated ghrelin and total peptide-YY (PYY) measured hourly in response to two standardised test meals. An ad libitum buffet meal was provided at the end of each condition. Based on linear mixed model analysis, total area under the curve for satisfaction was 16% higher (P = 0.021) and overall appetite was 11% lower during SIT-ACT vs EX-SIT (P = 0.018), with no differences between SIT-ACT and SIT. Time series analysis indicated that SIT-ACT reduced subjective appetite during the majority of the post-lunch period compared with SIT and EX-SIT, with some of these effects reversed earlier in the afternoon (P < 0.05). Total PYY and acylated ghrelin did not differ between conditions. Relative energy intake was 760 kJ lower during SIT-ACT vs SIT (P = 0.024). High-intensity physical activity breaks may be effective in acutely suppressing appetite; yet, appetite-regulating hormones may not explain such responses.

Live-streaming Activity and Relaxation Breaks: a (Home-)Office-Compatible Approach to Promote Break Recovery, Mood, and Attention?

The aim of this study is to investigate whether short, live-streaming activity and relaxation lunch breaks have positive associations with office workers' mood (calmness, valence, and energetic arousal), back pain, and attention after break and whether these associations are mediated by better break recovery. Additionally, we considered the two respite interventions as resources possibly buffering the effects of elevated situational job demands. Ten-minute break exercises were conducted during lunch breaks via Zoom live-stream, and data on those days were compared with data on days on which participants spent their breaks as usual. Our sample of 34 office workers provided data for 277 work days (209 in the home office and 68 on site at the company). Multilevel path models revealed positive total associations of both respite interventions with the mood dimension of calmness. Activity breaks additionally showed a positive association with the energetic arousal dimension of mood, while relaxation breaks were positively related to objectively measured cognitive performance. Interestingly, activity breaks moderated the relationships of job demands with calmness and valence, indicating their function as a stress-buffering resource. There were no significant associations between the two respite interventions and back pain. Supplemented by participants' feedback, the findings of this study suggest that offering short virtually guided break exercises may represent a feasible and office-compatible approach to promote break recovery, mood and functionality at work, especially regarding home-office work. Possible advantages and disadvantages of the live-streaming format are discussed.

Lower Amounts of Daily and Prolonged Sitting Do Not Lower Free-Living Continuously Monitored Glucose Concentrations in Overweight and Obese Adults: A Randomised Crossover Study.

This study compared the short-term continuously monitored glucose responses between higher and lower amounts of prolonged sitting in overweight and obese adults under free-living conditions. In a randomised crossover design, 12 participants (age 48 ± 10 years, body mass index 33.3 ± 5.5 kg/m2) completed two four-day experimental regimens while wearing a continuous glucose monitor, as follows: (1) uninterrupted sitting (participants were instructed to sit for ≥10 h/day and accrue ≥7, 1 h sitting bouts each day), and (2) interrupted sitting (participants were instructed to interrupt sitting every 30 min during ten of their waking hours with 6−10 min of activity accrued in each hour). Linear mixed models compared outcomes between regimens. None of the continuously monitored glucose variables differed between regimens, e.g., 24 h net incremental area under the glucose curve was 5.9 [95% CI: −1.4, 13.1] and 5.6 [95% CI: −1.7, 12.8] mmol/L∙24 h, respectively (p = 0.47). Daily sitting (−58 min/day, p = 0.001) and sitting bouts lasting ≥30 min (−99 min/day, p < 0.001) were significantly lower and stepping time significantly higher (+40 min/day, p < 0.001) in the interrupted sitting than the uninterrupted sitting regimen. In conclusion, lower amounts of daily and prolonged sitting did not improve free-living continuously measured glucose among overweight and obese adults.

ABBaH teens: Activity Breaks for Brain Health in adolescents: study protocol for a randomized crossover trial.

BACKGROUND: Physical activity breaks are widely being implemented in school settings as a solution to increase academic performance and reduce sitting time. However, the underlying physiological mechanisms suggested to improve cognitive function from physical activity and the frequency, intensity, and duration of the breaks remain unknown. This study will investigate the effects of frequent, short physical activity breaks during prolonged sitting on task-related prefrontal cerebral blood flow, cognitive performance, and psychological factors. Additionally, the moderating and mediating effects of arterial stiffness on changes in cerebral blood flow will be tested. METHODS: This is a protocol for a randomized crossover study that will recruit 16 adolescents (13-14 years old). Participants will undergo three different conditions in a randomized order, on three separate days, involving sitting 80 min with a different type of break every 17 min for 3 min. The breaks will consist of (1) seated social breaks, (2) simple resistance activities, and (3) step-up activities. Before and after the 80-min conditions, prefrontal cerebral blood flow changes will be measured using functional near-infrared spectroscopy (primary outcome), while performing working memory tasks (1-, 2-, and 3-back tests). Arterial stiffness (augmentation index and pulse wave velocity) and psychological factors will also be assessed pre and post the 80-min interventions. DISCUSSION: Publication of this protocol will help to increase rigor in science. The results will inform regarding the underlying mechanisms driving the association between physical activity breaks and cognitive performance. This information can be used for designing effective and feasible interventions to be implemented in schools. TRIAL REGISTRATION: www.ClinicalTrials.gov , NCT04552626 . Retrospectively registered on September 21, 2020.