Search Results (20)

This article introduces a novel modular suspended underwater dredging robot used for the biochemical reaction tanks of underground water treatment plants. The presented underwater robot can be used to perform dredging operations without touching underwater bottom facilities. The approach achieved a suction and jet-of-pump combination. This requires the underwater robot system to maintain a stable operation attitude in turbulent water flow which is generated by the pump. The study involves the overall design of underwater robots coordinated with the dredging module and details the development of a ground control platform and underwater sensing sonar system. Depending on the location of the dredging, the robot has two operation modes: suspended mode and bottom sitting mode. The experimental results validate the feasibility and effectiveness of the underwater dredging robot. This research can achieve dredging in biochemical reaction tanks without interrupting operations and facilitates the development of intelligent operations in the water treatment industry. Full article

People with a spinal cord injury (SCI) report less physical activity than other populations and may engage in more sedentary behaviour (SB), especially sitting time. SB negatively impacts physiological and psychosocial outcomes in the general population, yet minimal research has explored the effects in people with SCI. The goal of this scoping review was to catalogue and describe the effects of acute SB among people with SCI. We searched four databases before February 2024 for studies in which people with any SCI sat, laid, or reclined for more than one hour in a day, and any physiological, psychological, or behavioural (i.e., SB time) outcome was measured. In total, 2021 abstracts were screened, and eight studies were included (n = 172 participants). The studies were characterized by varied definitions, manipulations, and measures of SB. Most measured outcomes were physiological (e.g., metabolic, blood pressure), followed by behavioural (e.g., SB time) and psychological (e.g., well-being, affect). When SB was interrupted, only postprandial glucose and affect improved. Based on two studies, participants engaged in 1.6 to 12.2 h of SB per day. Average uninterrupted wheelchair sitting bouts lasted 2.3 h. Based on the very limited body of research, it is impossible to draw any conclusions regarding the nature, extent, or impact of SB in people with SCI. There is much work to carry out to define SB, test its effects, and determine if and how people with SCI should reduce and interrupt SB. Full article

Older adults sit during most hours of the day; more than 30% are considered physically inactive. The accumulation of prolonged sitting time is an exercise-independent risk factor for aging-related conditions such as cardiometabolic disease and cancer. Archival plasma samples from a randomized controlled, four-condition crossover study conducted in 10 postmenopausal women with overweight or obesity were analyzed. During 5-hour conditions completed on separate days, the trial tested three interruption modalities: two-minute stands each 20 min (STS), hourly ten-minute standing breaks (Stand), hourly two-minute walks (Walk), and a controlled sit. Fasting baseline and 5-hour end point (2 h postprandial) samples were used for targeted metabolomic profiling. Condition-associated metabolome changes were compared using paired t-tests. STS eliminated the postprandial elevation of amino acid metabolites that was observed in the control. A norvaline derivative shown to have anti-hypertensive and -hyperglycemic effects was significantly increased during Stand and STS. Post-hoc testing identified 19 significantly different metabolites across the interventions. Tight metabolite clustering by condition was driven by amino acid, vasoactive, and sugar metabolites, as demonstrated by partial least squares-discriminant analyses. This exploratory study suggests that brief, low-intensity modalities of interrupting prolonged sitting can acutely elucidate beneficial cardiometabolic changes in postmenopausal women with cardiometabolic risk. Full article

Sedentary behavior (SB) is an essential risk factor for obesity, cardiovascular disease, and type 2 diabetes. Though certain levels of physical activity (PA) may attenuate the detrimental effects of SB, the inflammatory and cardiometabolic responses involved are still not fully understood. The focus of this secondary outcome analysis was to describe how light-intensity PA snacks (LIPASs, alternate sitting and standing, walking or standing continuously) compared with uninterrupted prolonged sitting affect inflammatory and cardiometabolic risk markers. Seventeen young adults with overweight and obesity participated in this study (eight females, 23.4 ± 3.3 years, body mass index (BMI) 29.7 ± 3.8 kg/m², glycated hemoglobin A1C (HbA_1c) 5.4 ± 0.3%, body fat 31.8 ± 8.2%). Participants were randomly assigned to the following conditions which were tested during an 8 h simulated workday: uninterrupted prolonged sitting (SIT), alternate sitting and standing (SIT-STAND, 2.5 h total standing time), continuous standing (STAND), and continuous walking (1.6 km/h; WALK). Each condition also included a standardized non-relativized breakfast and lunch. Venous blood samples were obtained in a fasted state at baseline (T₀), 1 h after lunch (T₁) and 8 h after baseline (T₂). Inflammatory and cardiometabolic risk markers included interleukin-6 (IL-6), c-reactive protein (CRP), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TGs), visceral fat area (VFA), triglyceride-glucose (TyG) index, two lipid ratio measures, TG/HDL-C and TC/HDL-C, albumin, amylase (pancreatic), total protein, uric acid, and urea. We found significant changes in a broad range of certain inflammatory and cardiometabolic risk markers during the intervention phase for IL-6 (p = 0.014), TG (p = 0.012), TC (p = 0.017), HDL-C (p = 0.020), LDL-C (p = 0.021), albumin (p = 0.003), total protein (p = 0.021), and uric acid (p = 0.040) in favor of light-intensity walking compared with uninterrupted prolonged sitting, alternate sitting and standing, and continuous standing. We found no significant changes in CRP (p = 0.529), creatinine (p = 0.199), TyG (p = 0.331), and the lipid ratios TG/HDL-C (p = 0.793) and TC/HDL-C (p = 0.221) in response to the PA snack. During a simulated 8 h work environment replacement and interruption of prolonged sitting with light-intensity walking, significant positive effects on certain inflammatory and cardiometabolic risk markers were found in young adults with overweight and obesity. Full article

Background: Physical activity (PA) and/or exercise improves postprandial cardiometabolic risk markers; however, the optimal exercise intensity, frequency, and dose remain unclear. We aimed to (1) compare the acute metabolic effects of interrupted prolonged sitting with PA bouts of different frequencies and durations on blood glucose, insulin, and triacylglycerol responses, and (2) compare the effects of the different types and different times of PA breaks on these measures. Methods: A literature search was carried out using four databases. Network meta-analysis (NMA) and paired meta-analysis were performed to estimate the total standardized mean differences (SMDs) with 95% confidence intervals (95%CI). Results: According to the NMA, compared to prolonged sitting, every 30 min interruption had the highest probability (SUCRA) of being the best intervention for improving blood glucose (SUCRA = 81.8%, SMD = −1.18, 95%CI: −1.72, −0.64) and insulin (SUCRA = 77.5%, SMD = −0.98, 95%CI: −1.36, −0.60). Additionally, every 20 min interruption also significantly lowered blood glucose (SMD = −0.89, 95%CI: −1.52, −0.27) and insulin (SMD = −0.94, 95%CI: −1.41, −0.46). Pairwise meta-analysis suggested that frequent breaks by light-intensity PA significantly lowered glucose (SMD = −1.45, 95%CI: −2.32, −0.57) and insulin (SMD = −1.04, 95%CI: −1.53, −0.55). The same was found for frequent breaks by moderate-to-vigorous PA, which also significantly lowered glucose (SMD = −0.6, 95%CI: −0.83, −0.37) and insulin (SMD = −0.53, 95%CI: −0.73, −0.32). Conclusions: According to the NMA, performing short bouts of PA every 30 min is the most effective prolonged sitting intervention for improving blood glucose and insulin. More evidence is needed to determine the optimal type and time of PA breaks for braking sedentary sitting. PROSPERO Registration: CRD42022340036. Full article

(1) There is growing concern surrounding the adverse effects of prolonged sitting on health, yet its impact on post-exercise recovery remains relatively unexplored. This study aimed to better understand the potential influence of habitual prolonged sitting on recovery time and the unfavorable impact prolonged sitting may have on time to recovery, as assessed by muscle damage and inflammatory markers and an isokinetic dynamometer. (2) Nine college-age men (mean age ± SD = 22.1 ± 3.1 years, body mass = 80.9 ± 15.7 kg, height = 171 ± 9.0 cm, Body Mass Index (BMI) = 27.6 ± 4.9 kg·m²) participated in an exhaustive exercise protocol. Creatine Kinase (CK), Myoglobin (Mb), C-Reactive Protein (CRP), White Blood Cell Count (WBC), Peak Torque (PT), and muscle soreness were measured at baseline and 0, 24, 48, and 72 h post-exercise. Dietary and exercise logs were maintained during the 5-day testing procedure. (3) No significant differences were observed in muscle damage markers (CK [p = 0.068] and Mb [p = 0.128]), inflammatory markers (CRP [p = 0.814] and WBC [p = 0.140]), or PT [p = 0.255]) at any time point. However, a significant positive correlation was found between daily sitting time and the percent increase in CK concentration from 0 h to 72 h (r = 0.738, p = 0.023). Strong correlations were also noted between prolonged sitting and percent change in Mb concentration at 48 h (r = 0.71, p = 0.033) and 72 h (r = 0.889, p = 0.001). There was a significant two-way interaction for time × velocity (p = 0.043) for PT with a simple main effect for time at 60°·${\mathrm{s}}^{-1}$ (p = 0.038). No significant associations were detected between daily carbohydrate or protein intake and recovery markers (p > 0.05). (4) The findings suggest minimizing daily sitting time may expedite and potentially aid muscle recovery after an intense exercise bout, although further research is warranted to validate these findings. Full article

Background: Exercise videos that work to minimize cognitive load (the amount of information that working memory can hold at one time) are hypothesized to be more engaging, leading to increased PA participation. Purpose: To use a theory-based pragmatic tool to evaluate the cognitive load of instructor-led exercise videos associated with the Interrupting Prolonged Sitting with ACTivity (InPACT) program. Methods: Exercise videos were created by physical education teachers and fitness professionals. An evaluation rubric was created to identify elements each video must contain to reduce cognitive load, which included three domains with four components each [technical (visual quality, audio quality, matching modality, signaling), content (instructional objective, met objective, call-to-action, bias), and instructional (learner engagement, content organization, segmenting, weeding)]. Each category was scored on a 3-point scale from 0 (absent) to 2 (proficient). A video scoring 20–24 points induced low cognitive load, 13–19 points induced moderate cognitive load, and less than 13 points induced high cognitive load. Three reviewers independently evaluated the videos and then agreed on scores and feedback. Results: All 132 videos were evaluated. Mean video total score was 20.1 ± 0.7 points out of 24. Eighty-five percent of videos were rated low cognitive load, 15% were rated moderate cognitive load, and 0% were rated high cognitive load. The following components scored the highest: audio quality and matching modality. The following components scored the lowest: signaling and call-to-action. Conclusions: Understanding the use of a pragmatic tool is a first step in the evaluation of InPACT at Home exercise videos. Our preliminary findings suggest that the InPACT at Home videos had low cognitive load. If future research confirms our findings, using a more rigorous study design, then developing a collection of instructor-led exercise videos that induce low cognitive load may help to enhance youth physical activity participation in the home environment. Full article

Background: Sedentary behaviors have increased in recent years and their consequences have led the World Health Organization to make recommendations for promoting a more active lifestyle. The school environment has been defined as a key place for achieving this objective for children and adolescents. This systematic review and meta-analysis aims to analyze the effect of active-break interventions for interrupting prolonged sitting times during school-time on physical activity (PA) and sedentary behavior (SB), at school, in childhood and youth. Methods: A systematic review and meta-analysis were carried out, including clinical trials aimed at assessing the effects of interrupting prolonged sitting at school with active breaks on in-school PA and/or SB. Multimodal and static interventions were excluded. Six databases were analyzed: Medline, WOS, Cochrane Library, SPORT Discus, CINAHL and EMBASE. PA, SB; moderate-to-vigorous physical activity (MVPA) were the variables considered. Results: Nine studies were included, with a total of 2145 children between 6 and 12 years old. The heterogeneity in the duration (five–sixty min), the frequency (one–three times per-day up to three times per week), and duration (five days to three years) of the interventions was detected. The meta-analyses for in-school PA, MVPA, and SB were performed, showing a significant improvement in both PA and MVPA. Conclusions: Interrupting prolonged sitting with active-based school interventions could improve PA and MVPA levels during school time. (PROSPERO: CRD42022358933). Full article

There are many reports on the risk of falls in older adults but none regarding the risk among middle-aged people. We aimed to determine fall risk factors among middle-aged women. The participants comprised 1421 women aged 40 to 64 years; anthropometric and other measurements were obtained, and lifestyle factors were examined using a self-administered questionnaire. The participants were categorized into two groups (No-fall and Fall/Almost-fall) based on their questionnaire responses. The No-fall and Fall/Almost-fall groups comprised 1114 and 307 participants, respectively. Body mass index, abdominal circumference measurements, and prevalence of dyslipidemia were significantly higher in the Fall/Almost-fall group. Additionally, those in the Fall/Almost-fall group had a shorter two-step test, experienced difficulty performing the 40 cm single-leg sit-to-stand test, and had higher 25-question Geriatric Locomotive Function Scale (GLFS-25) scores than those in the No-fall group. The results of the adjusted logistic regression analysis indicated that physical activity, higher GLFS-25 scores, and sedentary time of more than seven hours were all risk factors for falling or almost falling. Longer sedentary time is a new risk factor for falls among middle-aged women. It is necessary for people to be concerned with their sedentary behavior, such as by reducing or interrupting continuous sedentary time. Full article

Background: Sedentary behavior (SB) is a negative routine for health, especially during advancing age. Promoting an active lifestyle and reducing SB is a global endeavor. The aim of this study was to analyze the effects of active school-based programs to interrupt prolonged sitting for daily physical activity (PA) and daily SB in children and adolescents. Methods: A systematic review was conducted. Clinical trials analyzing the effect of interrupting prolonged sitting with active breaks and classroom-based PA were included. Studies that implemented PA in class without interrupting prolonged sitting or those that implemented multimodal interventions were excluded. A systematic search was conducted in 6 databases: Medline, WOS, Cochrane Library, SPORTDiscus, CINAHL and EMBASE. Primary outcomes were daily PA and daily SB, while moderate-to vigorous physical activity (MVPA) was considered a secondary outcome. Results: Six studies were included, with a total of 976 participants between 6–14 years. The interventions were heterogeneous in duration of the sitting time interruption (5–30 min), frequency (1–3 times per-day up to three times per-week) and total duration (five days to three years). 50% of the studies scored “high risk” of bias. Three meta-analyses were performed for daily PA, MVPA and SB, showing a significant improvement in the daily PA and MVPA. Conclusions: School-based programs aimed to interrupt prolonged sitting could be a good strategy to improve daily PA and MVPA levels. (Registration number: CRD42022358933). Full article

Background: Sitting or standing during prolonged periods is related to leg swelling. It is unknown if interrupting sedentary behavior can attenuate lower leg swelling. We aimed to examine if adding sit-to-stand transitions prevents lower leg swelling as compared with uninterrupted motionless standing and sitting, using localized bioelectrical impedance raw parameters. Methods: Twenty adults participated in this crossover randomized controlled trial and acted out three conditions: (1) uninterrupted, motionless standing; (2) uninterrupted motionless sitting; (3) sit-to-stand transitions (1 min sitting followed by 1 min standing). Localized resistance (R), reactance (Xc), impedance (Z) and phase angle (PhA) were assessed at baseline, at 10 min and at 20 min for each condition. Results: For sitting and standing conditions, R and Xc values decreased after 10 and 20 min. Uninterrupted sitting resulted in the highest decrease in R (ΔSit − ΔStand = −9.5 Ω (4.0), p = 0.019; ΔSit − ΔInt = −11.6 Ω (4.0), p = 0.005). For standardized R (R/knee height), sitting was the condition with a greater decrease (ΔSit − ΔStand = −30.5 Ω/m (13.4), p = 0.025; ΔSit − ΔInt = −35.0 Ω/m (13.5), p = 0.011). Conclusions: Interrupting sedentary behavior by changing from sit to stand position during short periods may be effective at preventing leg swelling. Full article

Fitness and exercise may counteract the detrimental metabolic and mood adaptations during prolonged sitting. This study distinguishes the immediate effects of a single bout vs. work-load and intensity-matched repeated exercise breaks on subjective well-being, blood glucose, and insulin response (analyzed as area under the curve) during sedentary time; and assesses the influence of fitness and caloric intake on metabolic alterations during sedentariness. Eighteen women underwent cardiopulmonary exercise testing and three 4 h sitting interventions: two exercise interventions (70% VO₂max, 30 min, cycle ergometer: (1) cycling prior to sitting; (2) sitting interrupted by 5 × 6 min cycling), and one control condition (sitting). Participants consumed one meal with ad libitum quantity (caloric intake), but standardized macronutrient proportion. Exercise breaks (4057 ± 2079 μU/mL·min) reduced insulin values compared to a single bout of exercise (5346 ± 5000 μU/mL·min) and the control condition (6037 ± 3571 μU/mL·min) (p ≤ 0.05). ANCOVA revealed moderating effects of caloric intake (519 ± 211 kilocalories) (p ≤ 0.01), but no effects of cardiorespiratory fitness (41.3 ± 4.2 mL/kg/min). Breaks also led to lower depression, but higher arousal compared to a no exercise control (p ≤ 0.05). Both exercise trials led to decreased agitation (p ≤ 0.05). Exercise prior to sitting led to greater peace of mind during sedentary behavior (p ≤ 0.05). Just being fit or exercising prior to sedentary behavior are not feasible to cope with acute detrimental metabolic changes during sedentary behavior. Exercise breaks reduce the insulin response to a meal. Despite their vigorous intensity, breaks are perceived as positive stimulus. Detrimental metabolic changes during sedentary time could also be minimized by limiting caloric intake. Full article

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. Full article

Prolonged uninterrupted sitting and a typical Western meal, high in fat and refined sugar, can additively impair cognitive and cerebrovascular functions. However, it is unknown whether interrupting these behaviours, with a simple desk-based activity, can attenuate the impairment. The aim of this study was to determine whether regular leg fidgeting can off-set the detrimental effects of prolonged sitting following the consumption of a typical Western meal, on executive and cerebrovascular function. Using a randomized cross-over design, 13 healthy males consumed a Western meal and completed 180-min of prolonged sitting with leg fidgeting of 1 min on/4 min off (intervention [INT]) and without (control [CON]). Cognitive function was assessed pre and post sitting using the Trail Maker Test (TMT) parts A and B. Common carotid artery (CCA) blood flow, as an index of brain flow, was measured pre and post, and cerebral (FP1) perfusion was measured continuously. For TMT B the CON trial significantly increased (worsened) completion time (mean difference [MD] = 5.2 s, d = 0.38), the number of errors (MD = 3.33, d = 0.68) and cognitive fatigue (MD = 0.73, d = 0.92). Compared to CON, the INT trial significantly improved completion time (MD = 2.3 s, d = 0.97), and prevented declines in cognitive fatigue and a reduction in the number of errors. No significant changes in cerebral perfusion or CCA blood flow were found. Leg fidgeting for 1-min on/4-min off following a meal high in fats and refined sugars attenuated the impairment in executive function. This attenuation in executive function may not be caused by alterations in CCA blood flow or cerebral perfusion. Full article

The severe consequences of the present Corona Virus Disease 2019 COVID-19 pandemic seem to be closely related to an already ongoing (‘first’) pandemic, directly associated with a sedentary lifestyle. It seems evident that the prognosis after infection is substantially worse for individuals suffering from, for example, (visceral) obesity, cardiovascular disease, and diabetes type 2. Consequently, it may be considered highly relevant to gain insight into the potential beneficial effects of exercise interventions to strengthen the immune system, particularly in high-risk populations. For this reason, the exercise protocols that are suggested to strengthen the immune system, which can be executed by all ages and almost all physical conditions, were reviewed and evaluated. Previously published protocols range from interrupting prolonged sitting, to regular low-to-moderate exercise activities, to high intensity, typically interval, sports formats. Reported positive effects on immune functioning appear to be induced either directly or via beneficial metabolic and/or psychological effects and become measurable after 3 weeks to 3 months. Based in these findings, it appeared possible to design an optimal exercise protocol to maximize effects on immune functioning that should be executable for all, even under restricted (‘lockdown’) circumstances. Full article