An update on accumulating exercise and postprandial lipaemia: translating theory into practice

Over the last two decades, significant research attention has been given to the acute effect of a single bout of exercise on postprandial lipaemia. A large body of evidence supports the notion that an acute bout of aerobic exercise can reduce postprandial triacylglycerol (TAG) concentrations. However, this effect is short-lived emphasising the important role of regular physical activity for lowering TAG concentrations through an active lifestyle. In 1995, the concept of accumulating physical activity was introduced in expert recommendations with the advice that activity can be performed in several short bouts throughout the day with a minimum duration of 10 minutes per activity bout. Although the concept of accumulation has been widely publicised, there is still limited scientific evidence to support it but several studies have investigated the effects of accumulated activity on health-related outcomes to support the recommendations in physical activity guidelines. One area, which is the focus of this review, is the effect of accumulating exercise on postprandial lipaemia. We propose that accumulating exercise will provide additional physical activity options for lowering postprandial TAG concentrations relevant to individuals with limited time or exercise capacity to engage in more structured forms of exercise, or longer bouts of physical activity. The benefits of accumulated physical activity might translate to a reduced risk of cardiovascular disease in the long-term. Copyright © 2013 The Korean Society for Preventive Medicine

High intensity interval exercise and postprandial triacylglycerol

This review examined if high intensity interval exercise (HIIE) reduces postprandial triacylglycerol (TAG) concentrations. Fifteen studies were identified, in which the effect of interval exercise conducted at an intensity of >65% of maximal oxygen uptake was evaluated on postprandial TAG concentrations. Analysis was divided between studies which included supramaximal exercise and those which included submaximal interval exercise. Ten studies examined the effect of a single session of low-volume HIIE including supramaximal sprints on postprandial TAG. Seven of these studies noted reductions in postprandial total TAG area under the curve the morning after exercise of between ~10%-21% compared with rest but three investigations found no significant difference in TAG concentrations. Variations in the HIIE protocol used, inter-individual variation or insufficient time post-exercise for an increase in lipoprotein lipase activity are proposed reasons for the divergent results among studies. Five studies examined the effect of high-volume submaximal interval exercise on postprandial TAG. Four of these studies were characterised by high exercise energy expenditure and effectively attenuated total postprandial TAG concentrations by ~15%-30% but one study with a lower energy expenditure found no effect on TAG. The evidence suggests that supramaximal HIIE can induce large reductions in postprandial TAG concentrations but findings are inconsistent. Submaximal interval exercise offers no TAG metabolic or time advantage over continuous aerobic exercise but could be appealing in nature to some individuals. Future research should examine if submaximal interval exercise can reduce TAG concentrations in line with more realistic and achievable exercise durations of 30 minutes per day

Ecological processes associated with different animal taxa in urban environments

Urbanization is increasing globally with wide-ranging consequences for biodiversity and the ecological processes it performs. Yet knowledge of the range of ecological processes supported by biodiversity in urban environments, and the different taxa that perform these processes is poorly understood. We used a text-analysis approach to identify the research trends and gaps in knowledge in the literature on ecological processes provided by animals in urban environments. We found a divide in urban ecological processes research that grouped studies into those with an explicit link to ecological processes and those that focused on biodiversity and made an implicit link to ecological processes. We also found that the dominant taxa in urban ecological processes research were insects, which has more than twice as many studies as birds or mammals, potentially due to their recognized and explicit link to key processes and services (e.g., pollination, pollution biomonitoring) and disservices (e.g., pests, disease transmission). We found a further split between terrestrial and aquatic studies, with urban aquatic studies also declining in relative prevalence over the last 20 yr. To consolidate and advance research on ecological processes in urban environments, we suggest it will be important to bridge the divide between studies on explicit services and others on more general biodiversity. This might be achieved by placing greater focus on the processes provided by non-insect taxa, and by integrating aquatic and terrestrial perspectives. © 2021 The Authors

Squalene modulates fatty acid metabolism: Enhanced EPA/DHA in obese/diabetic mice (KK-A(y)) model

Biosynthesis of long-chain n-3 fatty acids from precursors is limited. In vivo effect of squalene (SQ) on the metabolic fate of n-3 fatty acid precursors in obese/diabetic KK-A(y) rodent model was evaluated in our work. Soybean oil, being rich in ALA (18:3 n-3; a known precursor of EPA/DHA), was chosen as the n-3 fatty acid precursor rich source. A high-fat diet (20%) containing 7% soybean oil (SO) was fed to obesity/diabetes-prone male KK-A(y) mice (control). In the case of diets fed to test groups, soybean oil was replaced with 5% SO and 2% SQ. Hepatic DHA levels increased (four fold) in SQ fed group over control (p<0.05). Gene and protein expressions of (5) and (6) desaturases, key enzymes involved in the fatty acid metabolism, further supported the results. Also, SQ exhibited a hypotriglyceridemic and hypoglycemic effect. The results clearly indicated the effect of SQ in modulating the n-3 fatty acid metabolism, including EPA/DHA synthesis in the presence of n-3 fatty acid precursor. This is the first report of enhancement of in vivo DHA/EPA by SQ and in turn, modulating the physiological fatty acid profile. Practical applications: Squalene (SQ) is an important marine biofunctional material that is found in some terrestrial sources as well. Squalene, being a cholesterol precursor, forms an interesting subject of research for its effect in vivo. SQ significantly enhanced proportions of EPA and/or DHA when their n-3 fatty acid precursors were available in the diet. The study further establishes the usefulness of SQ in functional food formulations. The work provides an important basis for further evaluation of the role of SQ in normal and disease conditions.KK-A(y) mice were fed high fat/sucrose diet to induce obesity/diabetes. Fat source in control diet was lard and soybean oil while experimental group diet contained 2% squalene+13% lard+5% soybean oil. Feeding squalene for 4weeks modulated fatty acid metabolism with increased docosahexaenoic acid (DHA) and decrease in triglycerides (TG), compared to control. The enhanced DHA in the fatty acid profile was supported by upregulated mRNA expression of (5)-desaturase enzyme and protein expression of (5) and (6) desaturases (FADS1 and FADS2). Additionally, squalene had a hypoglycemic effect in the mice

Influence of prolonged treadmill running on appetite, energy intake and circulating concentrations of acylated ghrelin

The effects of prolonged treadmill running on appetite, energy intake and acylated ghrelin (an appetite stimulating hormone) were examined in 9 healthy males over the course of 24 h. Participants completed 2 experimental trials (exercise and control) in a randomised - crossover fashion. In the exercise trial participants ran for 90 min at 68.8 ± 0.8% of maximum oxygen uptake followed by 8.5 h of rest. Participants returned to the laboratory on the following morning to provide a fasting blood sample and ratings of appetite (24 h measurement). No exercise was performed on the control trial. Appetite was measured within the laboratory using visual analogue scales and energy intake was assessed from ad libitum buffet meals. Acylated ghrelin was determined from plasma using an ELISA assay. Exercise transiently suppressed appetite and acylated ghrelin but each remained no different from control values in the hours afterwards. Furthermore, despite participants expending 5324 kJ during exercise there was no compensatory increase in energy intake (24 h energy intake; control 17191 kJ, exercise 17606 kJ). These findings suggest that large energy deficits induced by exercise do not lead to acute compensatory responses in appetite, energy intake or acylated ghrelin

Comparison of Oxidative Stability of Monogalactosyl Diacylglycerol, Digalactosyl Diacylglycerol, and Triacylglycerol Containing Polyunsaturated Fatty Acids

Oxidative stability of three different lipid classes, namely, monogalactosyl diacylglycerol (MGDG) and digalactosyl diacylglycerol (DGDG) from spinach and edible brown seaweed (Akamoku) and triacylglycerol (TAG) of linseed oil was compared. Analysis of oxygen consumption and polyunsaturated fatty acid (PUFA) composition demonstrated that spinach DGDG had the highest oxidative stability, followed by Akamoku DGDG, Akamoku MGDG, spinach MGDG, and linseed TAG. These results disagree with the order of oxidative stability expected from the average number of bis-allylic positions of each lipid. Additionally, DGDG constituents of both spinach and Akamoku showed higher oxidative stability than their MGDG constituents. The unusual oxidative stability of MGDG and DGDG could be conferred by the protection of bis-allylic positions of the PUFA against oxidative attack by the galactosyl moiety of the GL

A single session of treadmill running has no effect on plasma total ghrelin concentrations

Ghrelin is a hormone stimulating hunger. Intense exercise has been shown to temporarily suppress hunger post-exercise. The present study investigated whether post-exercise hunger suppression is mediated by reduced plasma total ghrelin concentrations

Risk prediction of landslide and debris flow using slope gradation map obtained from airborne laser scanning

The slope gradation map which is obtained from airborne laser scanning is very important tool to detect hazardous sites of landslide, debris flow and others. The features of the images (what the images are represented) in the map were confirmed by field survey. The study area, Tamagashi is situated in the Kibi Plateau area, Okayama City, Japan. The map helps to distinguish between artificial microrelief and natural microtopography very well. Small scarps (even 0.5m high), rocky cliffs and large blocks (larger than 2m) are identified in the map. The detail images of the microrelief suggest threatening sites. The merit of the map leads us to find the site in the field easily. We will not miss the threatening sites by using the map

Different patterns of walking and postprandial triglycerides in older women

Purpose: Although a single bout of continuous exercise (≥30 min) reduces postprandial triglyceride (TG), little evidence is available regarding the effect of multiple short (≤10 min) bouts of exercise on postprandial TG in individuals at increased risk of cardiovascular diseases. This study compared the effect of different patterns of walking on postprandial TG in postmenopausal, older women with hypertriglyceridemia. Methods: Twelve inactive women (aged 71 ± 5 yrs, mean ± S.D.) with hypertriglyceridemia (fasting TG ≥ 1.70 mmol/L) completed three, one-day laboratory-based trials in a random order: 1) control, 2) continuous walking, and 3) multiple short bouts of walking. On the control trial, participants sat in a chair for 8 hours. For the walking trials, participants walked briskly in either one 30-min bout in the morning (0900-0930) or twenty 90-sec bouts over 8 hours. Except for walking both exercise trials mimicked the control trial. In each trial, participants consumed a standardized breakfast (0800) and lunch (1100). Venous blood samples were collected in the fasted state and at 2, 4, 6 and 8 h after breakfast. Results: The serum TG incremental area under the curve was 35% and 33% lower on the continuous and multiple short bouts of walking trials than the control trial (8.2 ± 3.1 vs 8.5 ± 5.4 vs 12.7 ± 5.8 mmol∙8h/L respectively, main effect of trial: ES = 0.459, P = 0.001). Conclusions: Accumulating walking in short bouts limits postprandial TG in at-risk, inactive older women with fasting hypertriglyceridemia