Altering fatty acid availability does not impair prolonged, continuous running to fatigue: evidence for carbohydrate dependence

We determined the effect of suppressing lipolysis via administration of nicotinic acid (NA) on fuel substrate selection and half-marathon running capacity. In a single-blinded, Latin square design, 12 competitive runners completed four trials involving treadmill running until volitional fatigue at a pace based on 95% of personal best half-marathon time. Trials were completed in a fed or overnight fasted state: 1) carbohydrate (CHO) ingestion before (2 g CHO·kg−1·body mass−1) and during (44 g/h) [CFED]; 2) CFED plus NA ingestion [CFED-NA]; 3) fasted with placebo ingestion during [FAST]; and 4) FAST plus NA ingestion [FAST-NA]. There was no difference in running distance (CFED, 21.53 ± 1.07; CFED-NA, 21.29 ± 1.69; FAST, 20.60 ± 2.09; FAST-NA, 20.11 ± 1.71 km) or time to fatigue between the four trials. Concentrations of plasma free fatty acids (FFA) and glycerol were suppressed following NA ingestion irrespective of preexercise nutritional intake but were higher throughout exercise in FAST compared with all other trials (P < 0.05). Rates of whole-body CHO oxidation were unaffected by NA ingestion in the CFED and FAST trials, but were lower in the FAST trial compared with the CFED-NA trial (P < 0.05). CHO was the primary substrate for exercise in all conditions, contributing 83-91% to total energy expenditure with only a small contribution from fat-based fuels. Blunting the exercise-induced increase in FFA via NA ingestion did not impair intense running capacity lasting ∼85 min, nor did it alter patterns of substrate oxidation in competitive athletes. Although there was a small but obligatory use of fat-based fuels, the oxidation of CHO-based fuels predominates during half-marathon running

Regular walking breaks prevent the decline in cerebral blood flow associated with prolonged sitting.

Decreased cerebrovascular blood flow and function are associated with lower cognitive functioning and increased risk of neurodegenerative diseases. Prolonged sitting impairs peripheral blood flow and function, but its effects on the cerebrovasculature are unknown. This study explored the effect of uninterrupted sitting and breaking up sitting time on cerebrovascular blood flow and function of healthy desk workers. Fifteen participants (10 male, 35.8{plus minus}10.2 years, BMI: 25.5{plus minus}3.2 kg∙m-2) completed, on separate days, three 4-hr conditions in a randomised order: a) uninterrupted sitting (SIT), b) sitting with 2-min light intensity walking breaks every 30-min (2WALK) or c) sitting with 8-min light intensity walking breaks every 2-hrs (8WALK). At baseline and 4-hrs, middle cerebral artery blood flow velocity (MCAv), carbon dioxide reactivity (CVR) of the MCA and carotid artery were measured using transcranial Doppler (TCD) and duplex ultrasound respectively. Cerebral autoregulation (CA) was assessed with TCD using a squat-stand protocol and analysed to generate values of gain and phase in the very low, low, and high frequencies. There was a significant decline in SIT MCAv (-3.2{plus minus}1.2 cm.s-1) compared to 2WALK (0.6{plus minus}1.5 cm.s-1, p=0.02), but not between SIT and 8WALK (-1.2{plus minus}1.0 cm.s-1, p=0.14). For CA, the change in 2WALK very low frequency phase (4.47{plus minus}4.07 degrees) was significantly greater than SIT (-3.38{plus minus}2.82 degrees, p=0.02). There was no significant change in MCA or carotid artery CVR (p&gt;0.05). Results indicate that prolonged, uninterrupted sitting in healthy desk workers reduces cerebral blood flow, however this is offset when frequent, short-duration walking breaks are incorporated

The efficiency and effectiveness of utilizing diagrams in interviews: an assessment of participatory diagramming and graphic elicitation

Abstract Background This paper focuses on measuring the efficiency and effectiveness of two diagramming methods employed in key informant interviews with clinicians and health care administrators. The two methods are 'participatory diagramming', where the respondent creates a diagram that assists in their communication of answers, and 'graphic elicitation', where a researcher-prepared diagram is used to stimulate data collection. Methods These two diagramming methods were applied in key informant interviews and their value in efficiently and effectively gathering data was assessed based on quantitative measures and qualitative observations. Results Assessment of the two diagramming methods suggests that participatory diagramming is an efficient method for collecting data in graphic form, but may not generate the depth of verbal response that many qualitative researchers seek. In contrast, graphic elicitation was more intuitive, better understood and preferred by most respondents, and often provided more contemplative verbal responses, however this was achieved at the expense of more interview time. Conclusion Diagramming methods are important for eliciting interview data that are often difficult to obtain through traditional verbal exchanges. Subject to the methodological limitations of the study, our findings suggest that while participatory diagramming and graphic elicitation have specific strengths and weaknesses, their combined use can provide complementary information that would not likely occur with the application of only one diagramming method. The methodological insights gained by examining the efficiency and effectiveness of these diagramming methods in our study should be helpful to other researchers considering their incorporation into qualitative research designs

Effects of lowering body temperature via hyperhydration, with and without glycerol ingestion and practical precooling on cycling time trial performance in hot and humid conditions

Background: Hypohydration and hyperthermia are factors that may contribute to fatigue and impairment of endurance performance. The purpose of this study was to investigate the effectiveness of combining glycerol hyperhydration and an established precooling technique on cycling time trial performance in hot environmental conditions.Methods: Twelve well-trained male cyclists performed three 46.4-km laboratory-based cycling trials that included two climbs, under hot and humid environmental conditions (33.3 ± 1.1°C; 50 ± 6% r.h.). Subjects were required to hyperhydrate with 25 g.kg-1 body mass (BM) of a 4°C beverage containing 6% carbohydrate (CON) 2.5 h prior to the time trial. On two occasions, subjects were also exposed to an established precooling technique (PC) 60 min prior to the time trial, involving 14 g.kg-1 BM ice slurry ingestion and applied iced towels over 30 min. During one PC trial, 1.2 g.kg-1 BM glycerol was added to the hyperhydration beverage in a double-blind fashion (PC+G). Statistics used in this study involve the combination of traditional probability statistics and a magnitude-based inference approach.Results: Hyperhydration resulted in large reductions (-0.6 to -0.7°C) in rectal temperature. The addition of glycerol to this solution also lowered urine output (330 ml, 10%). Precooling induced further small (-0.3°C) to moderate (-0.4°C) reductions in rectal temperature with PC and PC+G treatments, respectively, when compared with CON (0.0°C, P\u3c0.05). Overall, PC+G failed to achieve a clear change in cycling performance over CON, but PC showed a possible 2% (30 s, P=0.02) improvement in performance time on climb 2 compared to CON. This improvement was attributed to subjects\u27 lower perception of effort reported over the first 10 km of the trial, despite no clear performance change during this time. No differences were detected in any other physiological measurements throughout the time trial.Conclusions: Despite increasing fluid intake and reducing core temperature, performance and thermoregulatory benefits of a hyperhydration strategy with and without the addition of glycerol, plus practical precooling, were not superior to hyperhydration alone. Further research is warranted to further refine preparation strategies for athletes competing in thermally stressful events to optimize health and maximize performance outcomes

A policy-based framework for the determination of management options to protect vulnerable marine ecosystems under the EU deep-sea access regulations

Vulnerable marine ecosystems (VMEs) are particularly susceptible to bottom-fishing activity as they are easily disturbed and slow to recover. A data-driven approach was developed to provide management options for the protection of VMEs under the European Union “deep-sea access regulations.” A total of two options within two scenarios were developed. The first scenario defined VME closure areas without consideration of fishing activity. Option 1 proposed closures for the protection of VME habitats and likely habitat, while Option 2 also included areas where four types of VME geophysical elements were present. The second scenario additionally considered fishing. This scenario used VME biomass—fishing intensity relationships to identify a threshold where effort of mobile bottom-contact gears was low and unlikely to have caused significant adverse impacts. Achieving a high level of VME protection requires the creation of many closures (> 100), made up of many small (∼50 km2) and fewer larger closures (> 1000 km2). The greatest protection of VMEs will affect approximately 9% of the mobile fleet fishing effort, while closure scenarios that avoid highly fished areas reduce this to around 4–6%. The framework allows managers to choose the level of risk-aversion they wish to apply in protecting VMEs by comparing alternative strategies.En prensa2,27

Anthropometric and physical performance characteristics of top-elite, elite and non-elite youth female team handball players

This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Sports Sciences on 16/02/2015, available online: http://www.tandfonline.com/doi/pdf/10.1080/02640414.2015.1012099In order to maximise the potential for success, developing nations need to produce superior systems to identify and develop talent, which requires comprehensive and up-to-date values on elite players. This study examined the anthropometric and physical characteristics of youth female team handball players (16.07 ± 1.30 y) in non-elite (n= 47), elite (n= 37) and top-elite players (n= 29). Anthropometric profiling included sum of eight skinfolds, body mass, stature, girths, breadths and somatotype. Performance tests included 20 m sprint, counter movement jump, throwing velocity, repeated shuttle sprint and jump ability test, and Yo-Yo Intermittent Recovery Test Level 1. Youth top-elite players had greater body mass, lean mass, stature, limb girths and breadths than elite and non-elite players, while only stature and flexed arm were higher in elite compared to non-elite players (all P 0.05). Top-elite performed better in most performance tests compared to both elite and non-elite players (P 0.05). Elite outperformed non-elite players in throwing velocity only. Findings reveal that non-elite players compare unfavourably to top-elite international European players in many anthropometric and performance characteristics, and differ in few characteristics compared to elite European club team players. This study is useful for emerging team handball nations in improving talent identification processes

Clinical and cost-effectiveness of a personalised health promotion intervention enabling independence in older people with mild frailty (‘HomeHealth’) compared to treatment as usual: study protocol for a randomised controlled trial

Background: Frailty is clinically associated with multiple adverse outcomes, including reduced quality of life and functioning, falls, hospitalisations, moves to long-term care and mortality. Health services commonly focus on the frailest, with highest levels of need. However, evidence suggests that frailty is likely to be more reversible in people who are less frail. Evidence is emerging on what interventions may help prevent or reduce frailty, such as resistance exercises and multi-component interventions, but few interventions are based on behaviour change theory. There is little evidence of cost-effectiveness. Previously, we co-designed a new behaviour change health promotion intervention (“HomeHealth”) to support people with mild frailty. HomeHealth is delivered by trained voluntary sector support workers over six months who support older people to work on self-identified goals to maintain their independence, such as strength and balance exercises, nutrition, mood and enhancing social engagement. The service was well received in our feasibility randomised controlled trial and showed promising effects upon outcomes. Aim: To test the clinical and cost-effectiveness of the HomeHealth intervention on maintaining independence in older people with mild frailty in comparison to treatment as usual (TAU).Methods: Single-blind individually randomised controlled trial comparing the HomeHealth intervention to TAU. We will recruit 386 participants from general practices and the community across three English regions. Participants are included if they are community-dwelling, aged 65+, with mild frailty according to the Clinical Frailty Scale. Participants will be randomised 1:1 to receive HomeHealth or TAU for 6 months. The primary outcome is independence in activities of daily living (modified Barthel Index) at 12 months. Secondary outcomes include instrumental activities of daily living, quality of life, frailty, wellbeing, psychological distress, loneliness, cognition, capability, falls, carer burden, service use, costs and mortality. Outcomes will be analysed using linear mixed models, controlling for baseline Barthel score and site. A health economic analysis and embedded mixed-methods process evaluation will be conducted. Discussion: This trial will provide definitive evidence on the effectiveness and cost-effectiveness of a home-based, individualised intervention to maintain independence in older people with mild frailty in comparison to TAU, that could be implemented at scale if effective

Identification of Biologically Relevant Compounds in Aboveground and Belowground Induced Volatile Blends

Plants under attack by aboveground herbivores emit complex blends of volatile organic compounds (VOCs). Specific compounds in these blends are used by parasitic wasps to find their hosts. Belowground induction causes shifts in the composition of aboveground induced VOC blends, which affect the preference of parasitic wasps. To identify which of the many volatiles in the complex VOC blends may explain parasitoid preference poses a challenge to ecologists. Here, we present a case study in which we use a novel bioinformatics approach to identify biologically relevant differences between VOC blends of feral cabbage (Brassica oleracea L.). The plants were induced aboveground or belowground with jasmonic acid (JA) and shoot feeding caterpillars (Pieris brassicae or P. rapae). We used Partial Least Squares—Discriminant Analysis (PLSDA) to integrate and visualize the relation between plant-emitted VOCs and the preference of female Cotesia glomerata. Overall, female wasps preferred JA-induced plants over controls, but they strongly preferred aboveground JA-induced plants over belowground JA-induced plants. PLSDA revealed that the emission of several monoterpenes was enhanced similarly in all JA-treated plants, whereas homoterpenes and sesquiterpenes increased exclusively in aboveground JA-induced plants. Wasps may use the ratio between these two classes of terpenes to discriminate between aboveground and belowground induced plants. Additionally, it shows that aboveground applied JA induces different VOC biosynthetic pathways than JA applied to the root. Our bioinformatic approach, thus, successfully identified which VOCs matched the preferences of the wasps in the various choice tests. Additionally, the analysis generated novel hypotheses about the role of JA as a signaling compound in aboveground and belowground induced responses in plants