Com o objetivo de avaliar se o exercício físico prolongado causa alterações miocárdicas em eqüinos de enduro e se estas alterações cardíacas têm influência no desempenho dos animais durante as provas, avaliaram-se 30 cavalos, divididos em três grupos de dez animais cada, sendo G1 composto por animais que percorreram distâncias acima de 100 km, G2 por animais que percorreram distâncias menores de 100 km e G3 por animais desqualificados por alterações metabólicas. Os animais foram avaliados em três momentos distintos, T0 (pré-exercício, em repouso), T1 (entre 30 e 60 minutos após o exercício) e T2 (entre 90 e 120 minutos pós-exercício). Realizaram-se o exame físico e o exame ecocardiográfico, além de colheita de amostras de sangue para determinação de troponina I cardíaca sérica e outras provas bioquímicas. Não houve diferença nos valores de troponina I cardíaca entre os diversos grupos nem nos diferentes tempos. Observou-se diminuição dos valores do diâmetro interno do ventrículo esquerdo em diástole e aumento de espessura de septo interventricular pós-exercício. Não houve diferença nos índices funcionais cardíacos e houve manutenção do débito cardíaco por aumento da freqüência cardíaca. Estas alterações ecocardiográficas de pequena magnitude foram mais evidentes nos animais desqualificados por alterações metabólicas e não parecem estar relacionadas a injúria miocárdica e sim secundárias a outras condições orgânicas. Conclui-se que o exercício físico prolongado não leva a injúrias cardíacas severas em cavalos de enduro. / With the purpose of evaluating myocardial alterations caused by prolonged physical exercise and whether these alterations influence the endurance horses\' performance during the races, 30 horses were evaluated, divided into three groups of ten horses each, being G1 composed by animals that performed distances of more than 100 km, G2 by animals that performed distances of less than 100 km and G3 by animals disqualified by metabolic alterations. The horses were evaluated in three distinct moments, T0 (pre-exercise, at rest), T1 (between 30 and 60 minutes post-exercise) and T2 (between 90 and 120 minutes post-exercise). Physical and echocardiographic examinations and else blood sample collection for the determination of cardiac troponin I and other biochemical tests were done. There was no difference in cardiac troponin I values neither between the various groups, nor between the moments. There was a decrease in the post-exercise values of the diastolic left ventricle internal diameter and an increase in the post-exercise values of the interventricular septal thickness. There was no difference in the cardiac functional indexes and the cardiac output was maintainded by augmentation of the heart rate. These minor echocardiographic alterations were more evident in the animals that were disqualified by metabolic alterations, and they don\'t seem to be related to myocardial injury, but secondary to other organic conditions. Based on these results, prolonged physical exercise doesn\'t seem to cause severe cardiac injuries in endurance horses.

Os objetivos desse trabalho foram avaliar se provas de enduro de diferentes distâncias causam estresse em equinos treinados, avaliar os efeitos das provas de enduro de diferentes distâncias sobre a atividade dos linfócitos e a relação com a imunocompetência dos equinos atletas e investigar a suplementação alimentar com glutamina como possível atenuante desse efeito depressivo do estresse sobre o sistema imunológico. Foram utilizados 33 cavalos treinados para enduro, 13 em 80 km, 14 em 120 km e 6 em 160 km, avaliados em 4 provas. Metade dos cavalos de cada categoria recebeu suplementação com glutamina via oral 30 dias antes e 14 dias após as provas. Amostras de sangue venoso foram colhidas antes (M0), imediatamente após a última inspeção veterinária (M1), 3 horas depois (M2) e nos haras 3 (M3), 7 (M4), e 14 dias (M5). Houve aumento dos níveis de cortisol, amônia, neutrófilos, aumento da relação neutrófilos/linfócitos e diminuição da contagem de linfócitos em M1 e M2 em todos os cavalos. Houve diminuição da relação CD4/CD8 nos animais de 120 (M2, M3 e M4) e 160 km (M3) que não receberam suplementação e diminuição de IFN em todos os cavalos. Nos suplementados, houve diminuição da relação CD4/CD8 em 80 (M2), 120 (M2 e M3) e 160 km (M3 e M4) e aumento tardio de IFN (M4 e M5) nos cavalos de 80 e 120 km. As concentrações de IL-2, IL-4 e IL-10 aumentaram após a prova em todos os cavalos, porém, nos suplementados o aumento foi maior ou mais prolongado. Com base nesses resultados, não foi possível observar estresse nos animais, nem imunodepressão, embora a suplementação tenha exercido efeito sobre os linfócitos. / The objectives of this study were to assess whether a different distances endurance races cause stress in trained horses, assess the effects of different distances an endurance races on the lymphocytes and relationship with the immune competence of equine athletes and investigate dietary supplementation with glutamine as possible mitigating this depressive effect of stress on the immune system . 33 well trained endurance horses were used, 13 at 80 km, 14 and 120 km and 6 in 160 km in 4 endurance rides . Half of the horses in each category received oral supplementation with glutamine to 30 days before and 14 days after the race. Venous blood samples were collected before (M0), immediately after the last veterinary inspection (M1), 3 hours after (M2) and in their farms 3 (M3), 7 (M4) and 14 days (M5) after. There was an increase in cortisol levels, ammonia and neutrophils, increase in neutrophils / lymphocytes ratio and reduction in lymphocyte counts at M1 and M2 in all horses. There was a decrease in LT CD4/CD8 ratio in 120 (M2, M3 and M4) and 160 km (M3) without supplementation and either a decreased in IFN in all animals. Horses that had received glutamine supplementation showed a decreased in CD4/CD8 ratio in 80 (M2), 120 (M2 and M3) and 160 km (M3 and M4) and late increase of IFN (M4 and M5) in 80 and 120 km. INF production was increased later (7 and 14 days) in 80 and 120 km horses that received supplementation and decreased in all 160 km. The concentrations of IL-2 , IL-4 and IL-10 increased after the race on all horses , but the increase was greater or more prolonged in supplemented ones. Based on these results, it was not possible to observe stress in these animals, or immunosuppression either, although supplementation has exerted effects on lymphocytes.

Peak oxygen uptake (VO2PEAK) in endurance exercise trained (ET =8) subjects (VO2PEAK = 61.7 1.6 ml 02.kg.min-1) was compared to the V02 PEAK of untrained (UT = 8) subjects (V02 PEAK = 38.4 1.7 ml 02 -kg.min1) after four hours of -6* head-down rest (HDR).Although both groups showed a reduction in blood volume (BV) following HDR, this decrement was greater for ET subjects (delta BV = -3.23 0.46 mi/kg; P <0.05). The ET subjects had a greater decrease in VO2=(delta 02E -5.58 1.05 ml 02-kg.min-1; P <0.05) than their UT peers (VO2PEAK = -2.44 0.79 ml02-kg.min-1). These data suggest that the greater reductions in VO2PE, observed for the ET group were associated with a greater BV loss resulting from 4 h of HDR prior to exercise.

Over the last decades, it has been progressively acknowledged that reducing the specific fuel consumption and the emission of pollutants as well as improving the thrust-to-weight ratio involves extensive research on advanced sealing technologies. Amongst these, brush seals are particularly well considered for their excellent leakage performance, their low friction properties, and their ability to cope with inevitable rotor excursions during flights. This thesis presents the experimental work that has been carried on in order to characterize carbon brush seals performance in function of the bristle pack geometry and the operating conditions. The analyzed parameters are the bristle free length, the density, and the inter-platedistance. The work, performed by the ULB in collaboration with French engine manufacturer Safran Aircraft Engines, provides first, a description of the test installation that reproduces accurately the severe working conditions encountered in a bearing chamber. A total of eight samples were submitted to extensive testing, and allowed to perform a qualitative analysis of the main performance indicators of a brush seal: the leakage flow, and the seal torque. Complex phenomena acting on the bristle pack were put in evidence under the effect of differential pressure androtation speed, and oil, which fundamentally deteriorate the leakage performance of a brush seal. Subsequently, performance models were developed through empirical correlations, based on the experimental data. They predict the leakage flow and the seal torque as a function of the geometrical parameters and operating conditions. In addition, hysteresis issues were also addressed, and an IR camera helped investigating the heat generation properties of a brush seal.Brush seal samples were submitted to endurance testing, in order to highlight wear mechanisms, and study the performance degradation with the operating time. Oil plays a major part in extending brush seals operating life, despite the leakage performance degradation. Finally, the correlations developed throughout the PhD thesis were used to develop an optimization process in function of the operating conditions of a modern aero-engine. Ultimately, large savings in air consumption were put in evidence when replacing labyrinth seals by brush seals. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished

Bakgrund: För att lyckas med att genomföra en Ironman krävs att man som utövare har en strategi gällande hur man ska disponera sin energi för att kunna bli en ”finisher”. Detta kallas pacing eller pacing strategi och är den egenstyrda ansträgningen som kan hjälpa utövaren att lyckas med sitt mål och optimera den egna prestationen. Att paca ”rätt” blir därför viktigt för att optimera den egna prestationen då loppet innehåller tre olika moment: simning, cykling och löpning. Syfte: Syftet med denna studie var att undersöka pulsmätning som ett sätt att studera och förstå pacing inom Ironman triathlon. Finns det ett samband mellan utövarens intensitet och cykeltid och har de deltagare som haft en liten pulsvariation en bättre sluttid? Metod: 22 deltagare genomförde ett test för att fastställa sin maxpuls, HRmax. I samband med Ironman Kalmar 2016 registrerades deltagarnas pulsdata med hjälp av pulsmätare och utifrån insamlad pulsdata beräknades deltagarnas intensitet och pulsvariation under cykelmomentet. Dessa värden korrelerades mot deltagarnas cykeltider. Resultat: Den relativa arbetspulsen för studiegruppen var 140 ±9.2 slag/min. Varken intensitet eller variation i intensitet visade något signifikant samband med sluttid även om en trend mot signifikans fanns för intensitet vs cykeltid, p=0.066. Slutsats: Spridningen i gruppen gällande vald intensitet var för stor för att tydligt kunna studera intensitetens betydelse för prestation under cykeldelen i ett IronMan och fler studier är nödvändiga för att kunna kartlägga detta. / Background: In order to succeed in an Ironman it is necessary to have a strategy on how to dispose your energy during the 8-16 hour race. This is called pacing or pacing strategy and is the self-selected effort that can help the competitor to optimize their performance. Based on heart rate measurement, this is particularly interesting during the 180 km cycle section, where drafting is not allowed.Aim: The aim of this investigation was to study pacing in Ironman thriathlon. Is there a relationship between the competitors intensity and biketime and did those who had smaller variation in intensity achieved a better biketime?Method: 22 competitive triathletes undertook a test to find out their HRmax. In conjunction with Ironman Kalmar 2016 the participants HR-data was registered with heartrate monitors and the data was then analyzed in order to determine the participants mean intensity and variation in intensity. These factors were used to understand pacing based on the participants heartrate and correlated to biketimes for each participant. Results: Average intensity for the participants was 140 ±9.2 bpm and the results show no significanct correlation between biketime and either the intensity chosen by the competitor or the variation in intensity. However, there was  a trend towards significance for the intensity vs biketime, p = 0.066. Conclusion: This study was unable to determine the effect of pacing due to the selected intensity within the group was too large to clearly study the importance of intensity for performance during the cycle part of an IronMan and further studies are required.

Suboptimal preparation for the Ironman triathlon can have detrimental effects on mental and physical condition. The purpose of this longitudinal investigation was to examine the relationship between a number of performance changes and fatigue markers during training for an Ironman as well as immediately after the event, in an attempt to better understand the effects of ultraendurance training. Eighteen athletes training for the Ironman; South Africa, 2009 were recruited for the study. Over the 6 month data collection period body mass, training load (TRIMP and Session x RPE methods), physiological responses (waking heart rate, postural dizziness, sleep ratings), changes in psychological state (profile of mood states - POMS), reported immunological responses (symptoms of illness), biochemical changes (salivary cortisol and alpha amylase) and performance (8 km submaximal running time trial (TT) and race day performance) were measured. These responses were compared to a control sample (n=15). Results show a significant increase (p<0.05) in training load (3899.4 ± 2517.8) four weeks prior to the event. Fatigue scores significantly increased (p<0.05) concurrently with this significant increase (p<0.05) in training. TT performance did not significantly (p<0.05) alter during the time course of training. It was however strongly correlated to training load (R2=0.85) and modestly related to race performance (R2=0.65). The signs and symptoms of upper respiratory tract infections (URTI) were prevalent during the training period, decreasing during the taper and race period. Large standard deviations were found within the majority of the responses. During the final two weeks of preparation, tension scores were significantly increased (p<0.05) while training load significantly decreased (p<0.05) during the final week of preparation. Cortisol increased significantly (p<0.05) immediately post race (0.507±0.15<g.DL-1) and 1.5 hours later (0.796±0.23<g.DL-1). Overall the results indicate that the POMS questionnaire was a sensitive marker of fatigue and stress associated with ultraendurance training, and that the event itself placed a great deal of stress on the athletes which was illustrated by the post event measures.

Concurrent training (CT) is defined as the development of both endurance and strength within the same exercise program. CT has been studied for decades, but the results has been diverse. However, very few have studied the effects of CT on the upper body musculature. Hence, this review set out to investigate the effects of combined strength and endurance training (ET) of the upper body on muscle hypertrophy, muscle strength and endurance variables. PubMed was searched with relevant search terms with varying combinations, such as concurrent training, combined strength and endurance training. After scanning the literature, a total of eight articles were included. The results suggest that muscle strength, exercise economy and time to exhaustion can effectively be improved by CT of the upper body. The effect of CT on upper body musculature were unclear. Some of the articles included suggests a decrease in whole body lean mass, which might simply be due to insufficient loading of the lower body musculature. In order to maintain muscle mass during a CT protocol, endurance athletes should aim to perform ST which targets muscles active during ET. However, the limited empiric literature available on CT of the upper body makes a conclusion hard to draw. This review shows that CT of the upper body is yet an unexplored and researchers should further investigate the effects of CT for the musculature of the upper body alone. If we gain more knowledge of the effects from concurrent training of the upper body, it could have several implications, both clinically and in a sport setting.

Lower back pain remains one of the most common problems in public health throughout the industrialized world (Strine and Hootman) (Shiri, Solovieva and K.). The prevalence is about 39-54% annually and 60-65% in a lifetime (Hillman, Wright and Rajaranam) (Leboeuf-Yde, N. and Lauritzen). In the United States, lower back pain is the second most common cause of disability, and is the highest cause of disability among men (Center for Disease Control, 2009). An individual quantitative physical examination to detect muscle deficiencies would be very useful for proper placement of workers in demanding physical jobs where back injuries are common. Trunk muscle extensor endurance might be the best approach for this issue.

Please read the abstract in the section 00front of this document / Dissertation (MA (Human Movement Science))--University of Pretoria, 2006. / Biokinetics, Sport and Leisure Sciences / unrestricted

With devastating natural disasters on the rise, technological improvements are needed in the field of search and rescue (SAR). Unmanned aerial vehicles (UAVs) would be ideal for the search function such that manned vehicles can be prioritized to distributing first-aid and ultimately saving lives. One of the major reasons that UAVs are under utilized in SAR is that they lack a long flight endurance which compromises their effectiveness. Dirigibles are well suited for SAR missions since they can hover and maintain lift without consuming energy and can be easily deflated for packaging and transportation. This research focuses on extending flight endurance of small-scale airship UAVs through improvements to the infrastructure design and flight trajectory planning. In the first area, airship design methodologies are reviewed leading to the development and experimental testing two hybrid fuel-electric power plants. The prevailing hybrid power plant design consists of a 4-stroke 14cc gasoline engine in-line with a brushless DC motor/generator and variable pitch propeller. The results show that this design can produce enough mechanical and electrical power to support 72 hours of flight compared to 1-4 hours typical of purely electric designs. A power plant configuration comparison method was also developed to compare its performance and endurance to other power plant configurations that could be used in dirigible UAVs. Overall, the proposed hybrid power plant has a 600% increase in energy density over that of a purely electric configuration. In the second area, a comprehensive multi-objective cost function is developed using spatially variable wind vector fields generated from computational fluid dynamic analysis on digital elevations maps. The cost function is optimized for time, energy and collision avoidance using a wavefront expansion approach to produce feasible trajectories that obey the differential constraints of the airship platform. The simulated trajectories including 1) variable vehicle velocity, 2) variable wind vector field (WVF) data, and 3) high grid resolutions were found to consume 50% less energy on average compared to planned trajectories not considering one of these three characteristics. In its entirety, this research addresses current UAV flight endurance limitations and provides a novel UAV solution to SAR surveillance.