A case study evaluation of competitors undertaking an antarctic ultra-endurance event: nutrition, hydration and body composition variables

Background: The nutritional demands of ultra-endurance racing are well documented. However, the relationship between nutritional consumption and performance measures are less obvious for athletes competing in Polar conditions. Therefore, the aim of this study was to evaluate dietary intake, hydration status, body composition and performance times throughout an 800-km Antarctic race. Methods: The event organisers declared that 17 competitors would participate in the South Pole race. Of the 17 competitors, pre-race data were collected from 13 participants (12 males and 1 female (M±SD): age: 40.1±8.9 years; weight 83.9±10.3kg; and body fat percentage: 21.9±3.8%). Dietary recall, body composition and urinary osmolarity were assessed pre-race, midway checkpoint and end race. Data were compared on the basis of fast finishers (the Norwegian team (n=3) who won in a record of 14 day) and slower finishers (the remaining teams (n=10) reaching the South Pole between 22 and 28 days). Results: The percentage contribution of macronutrients to daily energy intake for all participants was as follows: carbohydrate (CHO) - 23.7% (221±82 g.day-1), fat = 60.6% (251±127g.day-1) and protein = 15.7% (117±52g.day-1). Energy demands were closer met by faster finishers compared to slower finishers (5,332±469 vs. 3,048±1,140kcal.day-1, p=0.02). Average reduction in body mass throughout the race was 8.3±5.5kg, with an average loss of lean mass of 2.0±4.1kg. There as a significant negative correlation between changes in lean mass and protein intake (p=0.03), and lean mass and energy intake (p=0.03). End-race urinary osmolarity was significantly elevated for faster finishers compared to slower finishers and control volunteers (faster finishers: 933±157mOsmol.L-1; slower finishers: 543±92mOsmol.L-1; control: 515±165mOsmol.L-1, p+0.04). Conclusions: Throughout the race, both groups were subjected to a negative change in energy balance which partly explained reduced body mass. Carbohydrate availability was limited inferring a greater reliance on fat and protein metabolism. Consequently, loss in fat-free mass was more prevalent with insufficient protein and caloric intake, which may relate to performance

Multi vegetation model evaluation of the Green Sahara climate regime

During the Quaternary, the Sahara desert was periodically colonized by vegetation, likely because of orbitally induced rainfall increases. However, the estimated hydrological change is not reproduced in climate model simulations, undermining confidence in projections of future rainfall. We evaluated the relationship between the qualitative information on past vegetation coverage and climate for the mid-Holocene using three different dynamic vegetation models. Compared with two available vegetation reconstructions, the models require 500–800 mm of rainfall over 20°–25°N, which is significantly larger than inferred from pollen but largely in agreement with more recent leaf wax biomarker reconstructions. The magnitude of the response also suggests that required rainfall regime of the early to middle Holocene is far from being correctly represented in general circulation models. However, intermodel differences related to moisture stress parameterizations, biases in simulated present-day vegetation, and uncertainties about paleosoil distributions introduce uncertainties, and these are also relevant to Earth system model simulations of African humid periods

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

International Society of Sports Nutrition Position Stand: Nutritional recommendations for single-stage ultra-marathon; training and racing

Background. In this Position Statement, the International Society of Sports Nutrition (ISSN) provides an objective and critical review of the literature pertinent to nutritional considerations for training and racing in single-stage ultra-marathon. Recommendations for Training. i) Ultra-marathon runners should aim to meet the caloric demands of training by following an individualized and periodized strategy, comprising a varied, food-first approach; ii) Athletes should plan and implement their nutrition strategy with sufficient time to permit adaptations that enhance fat oxidative capacity; iii) The evidence overwhelmingly supports the inclusion of a moderate-to-high carbohydrate diet (i.e., ~60% of energy intake, 5 – 8 g⸱kg−1·d−1) to mitigate the negative effects of chronic, training-induced glycogen depletion; iv) Limiting carbohydrate intake before selected low-intensity sessions, and/or moderating daily carbohydrate intake, may enhance mitochondrial function and fat oxidative capacity. Nevertheless, this approach may compromise performance during high-intensity efforts; v) Protein intakes of ~1.6 g·kg−1·d−1 are necessary to maintain lean mass and support recovery from training, but amounts up to 2.5 g⸱kg−1·d−1 may be warranted during demanding training when calorie requirements are greater; Recommendations for Racing. vi) To attenuate caloric deficits, runners should aim to consume 150 - 400 kcal⸱h−1 (carbohydrate, 30 – 50 g⸱h−1; protein, 5 – 10 g⸱h−1) from a variety of calorie-dense foods. Consideration must be given to food palatability, individual tolerance, and the increased preference for savory foods in longer races; vii) Fluid volumes of 450 – 750 mL⸱h−1 (~150 – 250 mL every 20 min) are recommended during racing. To minimize the likelihood of hyponatraemia, electrolytes (mainly sodium) may be needed in concentrations greater than that provided by most commercial products (i.e., >575 mg·L−1 sodium). Fluid and electrolyte requirements will be elevated when running in hot and/or humid conditions; viii) Evidence supports progressive gut-training and/or low-FODMAP diets (fermentable oligosaccharide, disaccharide, monosaccharide and polyol) to alleviate symptoms of gastrointestinal distress during racing; ix) The evidence in support of ketogenic diets and/or ketone esters to improve ultra-marathon performance is lacking, with further research warranted; x) Evidence supports the strategic use of caffeine to sustain performance in the latter stages of racing, particularly when sleep deprivation may compromise athlete safety

Using System Pressure Control to Improve the Compressed Air System at Goulds Pumps

More and more manufacturers are aggressively pursuing energy-cost management in an effort to become more competitive. At most industrial sites, the compressed air system used throughout the plant is often the single largest user of electricity. Plants are typically operated with multiple compressors, each running at some previously manually established operating point. The operating points of each compressor are typically based on operator knowledge of the plant, which in many cases does not take into account the most efficient use of energy. Automated supervisory control of multiple compressors is a key part of a complete solution for demand-based control of compressed air systems. A project to develop a compressed air supervisory controller that will optimally schedule the set points of multiple compressor systems in response to demand for air in the plant has been undertaken at Goulds Pumps in Seneca Falls, New York. The project is cosponsored by the New York State Energy Research and Development Authority, New York State Electric and Gas Corporation, the Electric Power Research Institute, the Empire State Electric Energy Research Corporation, and Honeywell Inc. The effort is broken down into three phases: an audit, installation of compressed air controls, and a monitoring phase. As of January 1998, controls are being implemented and system monitoring is ongoing. The goal of the compressed air system is to optimize the energy efficiency of the 1,850 hp compressor system while reducing system pressure swings

Effects of 6 months of abatacept treatment on aortic stiffness in patients with rheumatoid arthritis

Sylvain Mathieu,1,2 Marion Couderc,1,2 Baptiste Glace,1,2 Bruno Pereira,2,3 Anne Tournadre,1,2 Jean-Jacques Dubost,1,2 Martin Soubrier1,21Department of Rheumatology, Gabriel-Montpied Hospital, 2Faculty of Medicine, University Clermont 1, 3D&eacute;l&eacute;gation de la Recherche Clinique, Gabriel-Montpied Hospital, Clermont-Ferrand, FranceBackground: Systemic inflammation plays an important role in the increased cardiac risk observed in rheumatoid arthritis (RA). Effective control of inflammation and disease activity may be of benefit in reducing cardiovascular risk in RA patients.Objective: Our study was conducted in patients with active RA to investigate the effects of 24-week abatacept treatment on aortic stiffness measured by pulse wave velocity (PWV).Results: The study included 21 patients, of whom 17 were females, with a mean age of 65.2&plusmn;13.7 years. Ten patients had positive rheumatoid factors, 16 positive anti-citrullinated protein antibodies, and 19 presented an erosive form of RA. Sixteen patients were nonresponders to anti-tumor necrosis factor-alpha treatments. After 6 months of abatacept treatment, there was a significant increase in PWV levels (9.8&plusmn;2.9 versus 8.5&plusmn;3.9 m/second; P=0.02). A nonsignificant increase in total cholesterol and low-density lipoprotein cholesterol was observed. There was also a significant increase in high-density lipoprotein cholesterol levels, which led to a nonsignificant decrease in atherogenic index. The improvement in disease activity was significant, and there was a decrease of systemic inflammatory parameters, but without reaching statistical significancy. Changes in PWV were significantly correlated with changes in Disease Activity Score on 28 joints based on erythrocyte sedimentation rate (r=0.46; P=0.035) and in high-density lipoprotein cholesterol (r=-0.38; P=0.046). No correlation was observed with changes in C-reactive protein and in other parameters of lipid profile or in steroid dose.Conclusion: The worsening of aortic stiffness found after 6 months of abatacept therapy might be due to an insufficient decrease in systemic inflammation.Keywords: arterial stiffness, cardiovascular risk markers, systemic inflammation, atherogenic inde

The Role of Theory in the Prevention of Sexual Violence in Sport.

Sexual violence (SV) remains at epidemic proportions in the U.S. and growing evidence demonstrates that youth and adults engaged in sport are at increased risk of victimization and perpetration of SV. Unfortunately, sport SV prevention strategies are rarely built on theory or theoretically grounded evidence, despite demonstrated effectiveness of such approaches. This study aimed to answer to questions: 1) Which theories are relevant to the development of effective SV prevention strategies in sport?; and 2) How has theory been incorporated into existing SV prevention literature on sport safety? A scoping review of the literature plus expert input identified 29 theories pertinent to SV prevention in sport. A systemized review of the literature regarding SV prevention in sport resulted in the identification and characterization of 41 published articles. Authors then examined theory\u27s role in prevention literature. This study identified 29 theories pertinent to SV prevention in sports and applicable across the behavioral spectrum. Most theories were rooted in the Behavioral (41%), Situational (24%) or Social/Attitudinal (21%) areas. Less common were theories grounded in Feminist (14%) domains. Theories were predominantly focused at the individual (42%), organizational (29%), and interpersonal (18%) ecological levels. Of the 41 sport prevention articles, 33 (83%) referred to a theory either explicitly or implicitly. Though most theories have been incorporated into prevention efforts, closer examination indicates that the majority were descriptive, unlikely to use a sophisticated methodology (10%; e.g., experimental, quasi-experimental), and rarely intended to assess a specific prevention program/strategy or policy (21%). Strong theoretical foundations are available for SV prevention research focused on sports, and their application appears to show value across the developmental spectrum of athletes. There remains a need for greater focus on theory-driven research intended to develop prevention strategies and policies designed to enhance athlete safety