These studies investigated the effect of physical inactivity (prolonged sitting) and physical activity (walking, standing, and moderate intensity exercise) on postprandial plasma triglyceride concentration (PPTG). In the first study, we evaluated the effect of low intensity intermittent walking at ~25% VO₂max (WALK) and energy-matched moderate intensity running at ~65% VO₂max (RUN) on PPTG, compared to a sitting control (SIT). RUN reduced incremental area under the curves for plasma triglyceride concentration (TG AUC[subscript I]), compared to WALK by 17.3% (p = 0.04) and SIT by 27% (p [less than] 0.001). The reduced TG AUC[subscript I] in RUN was accompanied by enhanced whole body insulin sensitivity, compared to WALK and SIT (for both, p [less than] 0.05). Whole body postprandial fat oxidation at rest following a high fat test meal intake was enhanced in RUN by 31% (P [less than] 0.001) and to a lesser extent in WALK by 8.4% (p [less than] 0.005), compared to SIT. In the second study, we evaluated 1) the effect of 2 days of prolonged sitting on PPTG, and 2) the effect of 4 days of SIT on the ability of an acute bout of exercise to reduce PPTG, compared to the same days of active walking and standing with calorically balanced diet (WALK+B). To distinguish the effect of prolonged sitting from the excess calorie effect, we had a sitting condition with calorically balanced diet (SIT+B) in addition to a sitting condition with hypercaloric diet (SIT+H). Following 2 days of respective food and activity control, WALK+B was lower in TG AUC[subscript T] by 21.3% and AUC[subscript I] by 17.4%, compared to SIT+H (for both, p [less than] 0.005). WALK+B was lower than SIT+B for TG AUC[subscript T] by 17.7% (p = 0.165) and AUC[subscript I] by 23.5% (p = 0.145) although statistical significance was not achieved. Remarkably, an acute exercise following 4 days of either SIT+H or SIT+B failed to reduce both TG AUC[subscript T] and AUC[subscript I], compared to SIT+B in HFTT1. The same exercise following 4 days of WALK+B, however, reduced both TG AUC[subscript T] by 29% and TG AUC[subscript I] by 32% in HFTT2, compared to SIT+B in HFTT1 (for both, p [less than] 0.02). Further, both SIT conditions reduced relative whole body fat oxidation in favor of increases in carbohydrate oxidation, compared to WALK+B by more than 40% in both HFTT1 and HFTT2. Taken together, our data suggest that 1) exercise intensity plays an independent role with higher intensity being more effective than lower intensity exercise in reducing PPTG, and 2) prolonged sitting with excess energy intake amplifies PPTG and prolonged sitting impairs the ability of an acute bout of moderate intensity exercise to reduce PPTG. This emphasizes the importance of regular participation in moderate-to-vigorous intensity exercise and reducing sitting time by increasing non-exercise physical activities (i.e., walking and standing) for the favorable postprandial metabolic health from the individual and public health perspectives. / text

Bakgrund: Diabetes är en allvarlig folkhälsosjukdom som påverkar kroppens egen möjlighet till att reglera blodets glukosvärde. Den största riskgruppen för att utveckla diabetes typ 2 är individer med övervikt. Regelbunden fysisk aktivitet har visat positiv inverkan på såväl glukosvärden. Vilken effekt korta pauser med fysisk aktivitet har på glukosvärde i blodet vid långvarigt stillasittande är inte lika utforskat. Det kan vara värdefullt som fysioterapeut att kunna ge relevanta rekommendationer angående fysisk aktivitet till individer med diabetes typ 2 eller övervikt för att kunna minska komplikationer. Syfte: Systematiskt granska enskilda studier och sammanväga tillförlitligheten för effekten på glukosvärde i blodet av korta pauser med fysisk aktivitet i samband med stillasittande hos individer med diabetes typ 2 och övervikt.  Metod: Litteratursökningen genomfördes i databasen Pubmed och resulterade i åtta studier inkluderades. Studierna kvalitétgranskades enligt PEDro scale och evidens graderingen genomfördes genom GRADEstud. Resultat: Korta pauser av fysisk aktivitet i samband med stillasittande resulterar i en signifikant minskning av glukosvärde hos individer med diabetes typ 2 eller övervikt. Kvalitétsgranskningen enligt PEDro visar att sex studier anses vara av måttlig kvalitét och två studier av hög kvalitét. Den sammanlagda tillförlitligheten enligt GRADEstud av underlaget bedömdes vara låg (++).  Konklusion: Effekten av fysisk aktivitet hos stillasittande individer med diabetes typ 2 eller övervikt visade ett minskat glukosvärde jämfört med dem som var långvarigt stillasittande. Evidensen bedömdes vara låg vilket visade på ett behov av fler högkvalitativa studier inom området för att kunna bekräfta resultatet. / Background: Diabetes is a public health disease that affects the body's own ability to regulate the blood's glucose. Overweight individuals have the highest risk of developing type 2 diabetes. The effect that physical activity has on glucose levels in conjunction with sedentary sitting is not as explored as regular interventions of physical activity. It can be valuable as a physiotherapist to be able to give recommendations to individuals with type 2 diabetes or overweight to reduce complications.  Purpose: Systematically review studies and their reliability on the effect of physical activity on blood glucose in conjunction with sedentary sitting on individuals with type 2 diabetes or overweight. Method: The literature search was conducted on the database Pubmed and resulted in eight studies. The studies quality was reviewed with PEDro scale and the evidence reviewed with GRADEstud. Results: Short breaks of physical activity in conjunction with sedentary sitting resulted in a significant decrease of glucose levels on individuals with diabetes type 2 and overweight. The quality review with PEDro showed that six studies were of moderate quality and two studies of high quality. The overall reliability according to GRADEstud was rated low(++). Conclusion: The effect of short breaks of physical activity in conjunction with sedentary sitting on individuals with diabetes type 2 or overweight shows decreased glucose levels compared with sedentary sitting. The evidence was rated low which shows a need for more high quality studies in the subject to confirm the results .

Low back pain (LBP) is a common occupational problem and continues to be the leading cause of occupational disability.  Among diverse known risk factors, sitting is commonly considered as an important exposure related to LBP.  Both modern living and contemporary work involve increased sedentary lifestyles, including more frequent and prolonged sitting.  At present, however, the causal role of sitting on LBP development is controversial due to the contribution of several moderating factors (e.g., task demands, duration of exposures, and presence of muscle fatigue).  A few studies have assessed low back loads in seated postures, but none has investigated the effects of prolonged sitting or time-dependent variations on spinal structure and spinal loading.  Adverse effects of muscle fatigue on low back pain are well documented, yet the specific relationship between muscle fatigue and sitting-related low back pain are not fully established.  In addition to these fundamental limitations in our understanding of the physical consequences of sitting, there is also little evidence regarding the effects of task requirements on muscle fatigue and spine loading.   Therefore, the main objectives of this work were, in the context of sitting, to: 1) develop and evaluate a method to assess paraspinal muscle fatigue using electrical stimulation; 2) develop and evaluate a method (model) to quantify biomechanical loads on the lumbar spine in a seated posture; and 3) quantify the effects of prolonged seated tasks on low back loads, body discomfort, and localized muscle fatigue (LMF).  The primary hypothesis was that exposure to sitting-related LBP risks is influenced by task requirements and sitting duration.   A muscle stimulation protocol was developed to measure stimulation responses in the lumbar extensors.  A stimulation protocol, which included one conditioning train along with three 16-second stimulation train at 2 Hz, was recommended as appropriate to measure those muscles potentially fatigued during prolonged seated tasks.  A three-dimensional, sitting-specific, fatigue-sensitive, time-dependent, electromyography (EMG)-based biomechanical model of the trunk was developed to investigate the effects of seated tasks and time-dependent variations on lumbosacral loading during sitting. Reasonable levels of correspondence were found between measured and predicted lumbosacral moments under a range of seated tasks.  Lastly, the effects of prolonged sitting and psychosocial work stress on low back were quantitatively identified.  Only prolonged sitting significantly increased trunk flexion angles and led to muscle fatigue.  Relatively weak correlations were found between subjective and objective measures, though the two fatigue measurement methods (based on EMG and stimulated responses) showed a good level of correspondence.   Overall, this work provides a quantitative assessment of biomechanical exposures associated with seated tasks.  The methods developed in this work make a contribution in terms of measurement/modeling approaches that can be used to assess LBP-relevant risks during prolonged sitting.  The results of this work provide a better understanding of the effects of prolonged sitting on the risk of developing sitting-related LBP.  Finally, results regarding the influences of prolonged sitting and psychosocial demands can be used to guide future job design. / Ph. D.

abstract: Purpose: The purpose of this study was to examine the acute effects of two novel intermittent exercise prescriptions on glucose regulation and ambulatory blood pressure. Methods: Ten subjects (5 men and 5 women, ages 31.5 &plusmn; 5.42 yr, height 170.38 &plusmn; 9.69 cm and weight 88.59 &plusmn; 18.91 kg) participated in this four-treatment crossover trial. All subjects participated in four trials, each taking place over three days. On the evening of the first day, subjects were fitted with a continuous glucose monitor (CGM). On the second day, subjects were fitted with an ambulatory blood pressure monitor (ABP) and underwent one of the following four conditions in a randomized order: 1) 30-min: 30 minutes of continuous exercise at 60 - 70% VO2peak; 2) Mod 2-min: twenty-one 2-min bouts of walking at 3 mph performed once every 20 minutes; 3) HI 2-min: eight 2-min bouts of walking at maximal incline performed once every hour; 4) Control: a no exercise control condition. On the morning of the third day, the CGM and ABP devices were removed. All meals were standardized during the study visits. Linear mixed models were used to compare mean differences in glucose and blood pressure regulation between the four trials. Results: Glucose concentrations were significantly lower following the 30-min (91.1 &plusmn; 14.9 mg/dl), Mod 2-min (93.7 &plusmn; 19.8 mg/dl) and HI 2-min (96.1 &plusmn; 16.4 mg/dl) trials as compared to the Control (101.1 &plusmn; 20 mg/dl) (P < 0.001 for all three comparisons). The 30-min trial was superior to the Mod 2-min, which was superior to the HI 2-min trial in lowering blood glucose levels (P < 0.001 and P = 0.003 respectively). Only the 30-min trial was effective in lowering systolic ABP (124 &plusmn; 12 mmHg) as compared to the Control trial (127 &plusmn; 14 mmHg; P < 0.001) for up to 11 hours post exercise. Conclusion: Performing frequent short (i.e., 2 minutes) bouts of moderate or high intensity exercise may be a viable alternative to traditional continuous exercise in improving glucose regulation. However, 2-min bouts of exercise are not effective in reducing ambulatory blood pressure in healthy adults. / Dissertation/Thesis / Ph.D. Physical Activity, Nutrition and Wellness 2013

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Nowadays, prolonged sitting among office workers is a widespread problem, which is highly related to several health problems. Many proposals have been reported and evaluated to address this issue. However, motivating and engaging workers to change health behavior to a healthier working life is still a challenge. In this project, a specific application has been deployed for real-time monitoring and alerting office workers for prolonged sitting. The proposed system consists of three distinct parts: The first one is an android smartwatch, which was used to collect sensor data e.g., accelerometer and gyro data, with a custom android wear app. The second one is an android application, which was developed to act as a gateway for receiving the smartwatch’s data and sending them to IBM Bluemix cloud with MQTT protocol. The final part is a Node-Red cloud application, which was deployed for storing, analyzing and processing of the sensor data for activity detection i.e., sitting or walking/standing. The main purpose of the last one was to return relevant feedback to the user, while combining elements from gaming contexts (gamification methods), for motivating and engaging office workers to a healthier behavior. The system was firstly tested for defining appropriate accelerometer thresholds to five participants (control group), and then evaluated with five different participants (treatment group), in order to analyze its reliability for prolonged sitting detection. The results showed a good precession for the detection. No confusing between sitting and walking/standing was noticed. Communication, storage and analysis of the data was successfully done, while the push notifications to the participants, for alerting or rewarding them, were always accurate and delivered on time. Every useful information was presented to the user to a web-based dashboard accessed through a smartphone, tablet or a PC.     The proposed system can easily be implemented at a real-life scenario with office workers. Certainly, there is a lot space for improvement, considering mostly the type of data registered at the system, the method for sitting detection, and the user interface for presenting relevant information. / Numera är förlängt sittande bland kontorsarbetare ett utbrett problem som är väldigt relaterat till flera hälsoproblem. Många förslag har rapporterats och utvärderas för att ta itu med denna fråga. Tydligen är det fortfarande en utmaning att motivera och engagera arbetstagare för att förändra deras hälsobeteende till hälsosammare arbetsliv. I detta projekt har en särskild applikation använts för realtidsövervakning och varnar kontorsarbetare för förlängt sittande. Det föreslagna systemet består av tre olika delar: Den första är en android smartwatch, som användes för att samla sensordata t.ex. accelerometer och gyrodata, med en anpassad android wear app. Den andra är en en androidapplikation som fungerade som en gateway för att ta emot smartwatchens data och skickar datan till IBM Bluemix-Cloud med MQTT-protokollet. Den sista delen är en Node-RED Cloud-Applikation som användes för lagring, analysering och behandling av sensordata för aktivitetsdetektering. Detta innebär sittande eller gå/stående med det huvudsakliga ändamålet att returnera relevant återkoppling till användaren, samtidigt som man kombinerar element från spelkontekster (gamification metoder), för att motivera och engagera arbetarna till ett hälsosammare beteende. Systemet testades först för att definiera lämpliga accelerometertrösklar till fem deltagare (kontroll grupp) och utvärderades sedan med fem olika deltagare (behandingsgrupp) för att analysera dess tillförlitlighet för långvarig sittdetektering. Resultaten visade en bra precession för detektionen. Ingen förvirring mellan att sitta och gå / stående märktes. Kommunikation, lagring och analys av data gjordes framgångsrikt, medan push-meddelandena till deltagarna, för att varna eller belöna dem, var alltid korrekta och levererade i tid. All användbar information presenterades för användaren på en webbaserad dashboard som nås via en smartphone surfplatta eller en dator. Det föreslagna systemet kan enkelt implementeras i ett verkligt scenario med kontorsarbetare. Visst finns det mycket utrymme för förbättring om man tänker på majoriteten av data som registrerats i systemet, metoden för sittande detektion och användargränssnittet för presentering av relevant information.