168 resultados para runners
Resumo:
The power output achieved at peak oxygen consumption (VO2 peak) and the time this power can be maintained (i.e., Tmax) have been used in prescribing high-intensity interval training. In this context, the present study examined temporal aspects of the VO2 response to exercise at the cycling power that output well trained cyclists achieve their VO2 peak (i.e., Pmax). Following a progressive exercise test to determine VO2 peak, 43 well trained male cyclists (M age = 25 years, SD = 6; M mass = 75 kg SD = 7; M VO2 peak = 64.8 ml(.)kg(1.)min(-1), SD = 5.2) performed two Tmax tests 1 week apart.1. Values expressed for each participant are means and standard deviations of these two tests. Participants achieved a mean VO2 peak during the Tmax test after 176 s (SD = 40; = 74% of Tmax, SD = 12) and maintained it for 66 s (SD = 39; M = 26% of Tmax, SD = 12). Additionally they obtained mean 95 % of VO2 peak after 147 s (SD = 31; M = 62 % of Tmax, SD = 8) and maintained it for 95 s (SD = 38; M = 38 % of Tmax, SD = 8). These results suggest that 60-70% of Tmax is an appropriate exercise duration for a population of well trained cyclists to attain VO2 peak during exercise at Pmax. However due to intraparticipant variability in the temporal aspects of the VO2 response to exercise at Pmax, future research is needed to examine whether individual high-intensity interval training programs for well trained endurance athletes might best be prescribed according to an athlete's individual VO2 response to exercise at Pmax.
Resumo:
The present study examined the effect of carbohydrate supplementation on changes in neutrophil counts, and the plasma concentrations of cortisol and myoglobin after intense exercise. Eight well-trained male runners ran on a treadmill for 1 h at 85% maximal oxygen uptake on two separate occasions. In a double-blind cross-over design, subjects consumed either 750 ml of a 10% carbohydrate (CHO) drink or a placebo drink on each occasion. The order of the trials was counterbalanced. Blood was drawn immediately before and after exercise, and I h after exercise. Immediately after exercise, neutrophil counts (CHO, 49%; placebo, 65%; P < 0.05), plasma concentrations of glucose (CHO, 43%; P
Resumo:
The purpose of this study was to compare the effects of exercise intensity and exercise-induced muscle damage on changes in anti-inflammatory cytokines and other inflammatory mediators. Nine well-trained male runners completed three different exercise trials on separate occasions: ( 1) level treadmill running at 60% VO2max (moderate-intensity trial) for 60 min; (2) level treadmill running at 85% VO2max (high-intensity trial) for 60 min; (3) downhill treadmill running ( - 10% gradient) at 60% VO2 max (downhill running trial) for 45 min. Blood was sampled before, immediately after and 1 h after exercise. Plasma was analyzed for interleukin-1 receptor antagonist (IL-1ra), IL-4, IL-5, IL-10, IL-12p40, IL-13, monocyte chemotactic protein-1 (MCP-1), prostaglandin E-2, leukotriene B-4 and heat shock protein 70 (HSP70). The plasma concentrations of IL-1ra, IL-12p40, MCP-1 and HSP70 increased significantly (P< 0.05) after all three trials. Plasma prostaglandin E-2 concentration increased significantly after the downhill running and high-intensity trials, while plasma IL-10 concentration increased significantly only after the high-intensity trial. IL-4 and leukotriene B4 did not increase significantly after exercise. Plasma IL-1ra and IL-10 concentrations were significantly higher ( P< 0.05) after the high-intensity trial than after both the moderate-intensity and downhill running trials. Therefore, following exercise up to 1 h duration, exercise intensity appears to have a greater effect on anti-inflammatory cytokine production than exercise-induced muscle damage.
Resumo:
Heat stroke is a life-threatening condition that can be fatal if not appropriately managed. Although heat stroke has been recognised as a medical condition for centuries, a universally accepted definition of heat stroke is lacking and the pathology of heat stroke is not fully understood. Information derived from autopsy reports and the clinical presentation of patients with heat stroke indicates that hyperthermia, septicaemia, central nervous system impairment and cardiovascular failure play important roles in the pathology of heat stroke. The current models of heat stroke advocate that heat stroke is triggered by hyperthermia but is driven by endotoxaemia. Endotoxaemia triggers the systemic inflammatory response, which can lead to systemic coagulation and haemorrhage, necrosis, cell death and multi-organ failure. However, the current heat stroke models cannot fully explain the discrepancies in high core temperature (Tc) as a trigger of heat stroke within and between individuals. Research on the concept of critical Tc: as a limitation to endurance exercise implies that a high Tc may function as a signal to trigger the protective mechanisms against heat stroke. Athletes undergoing a period of intense training are subjected to a variety of immune and gastrointestinal (GI) disturbances. The immune disturbances include the suppression of immune cells and their functions, suppression of cell-mediated immunity, translocation of lipopolysaccharide (LPS), suppression of anti-LPS antibodies, increased macrophage activity due to muscle tissue damage, and increased concentration of circulating inflammatory and pyrogenic cytokines. Common symptoms of exercise-induced GI disturbances include diarrhoea, vomiting, gastrointestinal bleeding, and cramps, which may increase gut-related LPS translocation. This article discusses the current evidence that supports the argument that these exercise-induced immune and GI disturbances may contribute to the development of endotoxaemia and heat stroke. When endotoxaemia can be tolerated or prevented, continuing exercise and heat exposure will elevate Tc to a higher level (> 42 degrees C), where heat stroke may occur through the direct thermal effects of heat on organ tissues and cells. We also discuss the evidence suggesting that heat stroke may occur through endotoxaemia (heat sepsis), the primary pathway of heat stroke, or hyperthermia, the secondary pathway of heat stroke. The existence of these two pathways of heat stroke and the contribution of exercise-induced immune and GI disturbances in the primary pathway of heat stroke are illustrated in the dual pathway model of heat stroke. This model of heat stroke suggests that prolonged intense exercise suppresses anti-LPS mechanisms, and promotes inflammatory and pyrogenic activities in the pathway of heat stroke.
Resumo:
Error condition detected Although coal may be viewed as a dirty fuel due to its high greenhouse emissions when combusted, a strong case can be made for coal to be a major world source of clean H-2 energy. Apart from the fact that resources of coal will outlast oil and natural gas by centuries, there is a shift towards developing environmentally benign coal technologies, which can lead to high energy conversion efficiencies and low air pollution emissions as compared to conventional coal fired power generation plant. There are currently several world research and industrial development projects in the areas of Integrated Gasification Combined Cycles (IGCC) and Integrated Gasification Fuel Cell (IGFC) systems. In such systems, there is a need to integrate complex unit operations including gasifiers, gas separation and cleaning units, water gas shift reactors, turbines, heat exchangers, steam generators and fuel cells. IGFC systems tested in the USA, Europe and Japan employing gasifiers (Texaco, Lurgi and Eagle) and fuel cells have resulted in energy conversions at efficiency of 47.5% (HHV) which is much higher than the 30-35% efficiency of conventional coal fired power generation. Solid oxide fuel cells (SOFC) and molten carbonate fuel cells (MCFC) are the front runners in energy production from coal gases. These fuel cells can operate at high temperatures and are robust to gas poisoning impurities. IGCC and IGFC technologies are expensive and currently economically uncompetitive as compared to established and mature power generation technology. However, further efficiency and technology improvements coupled with world pressures on limitation of greenhouse gases and other gaseous pollutants could make IGCC/IGFC technically and economically viable for hydrogen production and utilisation in clean and environmentally benign energy systems. (c) 2005 Elsevier B.V. All rights reserved.
Resumo:
Esta tese baseia-se na análise das campanhas políticas presidenciais, especificamente nos programas de Horário Gratuito de Propaganda Eleitoral veiculados na televisão brasileira de 1989 a 2002. Discorremos sobre os melhores momentos das campanhas políticas desse período, contudo, o enfoque mais abrangente é nas eleições de 2002. A presente pesquisa retrata pontos importantes relacionados à projeção da imagem dos candidatos à Presidência da República do Brasil. A comunicação, a trajetória, a televisão como veículo de comunicação de massa, a propaganda política, a publicidade eleitoral, o marketing político, o marketing eleitoral, em suma, as ferramentas utilizadas como aliadas imprescindíveis na conquista do poder.(AU)
Resumo:
Full text: It seems a long time ago now since we were at the BCLA conference. The excellent FIFA World Cup in Brazil kept us occupied over the summer as well as Formula 1, Wimbledon, Tour de France, Commonwealth Games and of course exam paper marking! The BCLA conference this year was held in Birmingham at the International Convention Centre which again proved to be a great venue. The number of attendees overall was up on previous years, and at a record high of 1500 people. Amongst the highlights at this year's annual conference was the live surgery link where Professor Sunil Shah demonstrated the differences in technique between traditional phacoemulsification cataract surgery and femtosecond assisted phacoemulsification cataract surgery. Dr. Raquel Gil Cazorla, a research optometrist at Aston University, assisted in the procedure including calibrating the femtosecond laser. Another highlight for me was the session that I chaired, which was the international session organised by IACLE (International Association of CL Educators). There was a talk by Mirjam van Tilborg about dry eye prevalence in the Netherlands and how it was managed by medical general practitioners (GPs) or optometrists. It was interesting to know that there are only 2 schools of optometry there and currently under 1000 registered optometrists there. It also seems that GPs were more likely to blame CL as the cause for dry eye whereas optometrists who had a fuller range of tests were better at solving the issue. The next part of the session included the presentation of 5 selected posters from around the world. The posters were also displayed in the main poster area but were selected to be presented here as they had international relevance. The posters were: 1. Motivators and Barriers for Contact Lens Recommendation and Wear by Nilesh Thite (India) 2. Contact lens hygiene among Saudi wearers by Dr. Ali Masmaly (Saudi) 3. Trends of contact lens prescribing and patterns of contact lens practice in Jordan by Dr. Mera Haddad (Jordan) 4. Contact Lens Behaviour in Greece by Dr. Dimitra Makrynioti (Greece) 5. How practitioners inform ametropes about the benefits of contact lenses and overcome the potential barriers: an Italian survey, by Dr. Fabrizio Zeri (Italy) It was interesting to learn about CL practice in different parts, for example the CL wearing population ration in Saudi Arabia is around 1:2 Male:Female (similar to other parts of the world) and although the sale of CL is restricted to registered practitioners there are many unregistered outlets, like clothing stores, that flout the rules. In Jordan some older practitioners will still advise patients to use tap water or even saliva! But thankfully the newer generation of practitioners have been educated not to advise this. In Greece one of the concerns was that some practitioners may advise patients to use disposable lenses for longer than they should and again it seems to be the practitioners with inadequate education that would do this. In India it was found that cost was one barrier to using contact lenses but also some practitioners felt that they shouldn’t offer CLs due to cost too. In Italy sensitive eyes and CL care and maintenance were the barriers to CL wear but the motivators were vision and comfort and aesthetics. Finally the international session ended with the IACLE travel award and educator awards presented by IACLE president Shehzad Naroo and BCLA President Andrew Yorke. The travel award went to Wang Ling, Jinling Institute of Technology, Nanjing, China. There were 3 regional Contact Lens Educator of the Year Awards sponsored by Coopervision and presented by Dr. J.C. Aragorn of Coopervision. 1. Asia Pacific Region – Dr. Rajeswari Mahadevan of Sankara Nethralaya Medical Research Foundation, Chennai, India 2. Americas Region – Dr. Sergio Garcia of University of La Salle, Bogotá and the University Santo Tomás, Bucaramanga, Colombia 3. Europe/Africa – Middle East Region: Dr. Eef van der Worp, affiliated with the University of Maastricht, the Netherlands The posters above were just a small selection of those displayed at this year's BCLA conference. If you missed the BCLA conference then you can see the abstracts for all posters and talks in a virtual issue of CLAE very soon. The poster competition was kindly sponsored by Elsevier. The poster winner this year was: Joan Gispets – Corneal and Anterior Chamber Parameters in Keratoconus The 3 runners up were: Debby Yeung – Scleral Lens Central Corneal Clearance Assessment with Biomicroscopy Sarah L. Smith – Subjective Grading of Lid Margin Staining Heiko Pult – Impact of Soft Contact Lenses on Lid Parallel Conjunctival Folds My final two highlights are a little more personal. Firstly, I was awarded Honorary Life Fellowship of the BCLA for my work with the Journal, and I would like to thank the BCLA, Elsevier, the editorial board of CLAE, the reviewers and the authors for their support of my role. My final highlight from the BCLA conference this year was the final presentation of the conference – the BCLA Gold Medal award. The recipient this year was Professor Philip Morgan with his talk ‘Changing the world with contact lenses’. Phil was the person who advised me to go to my first BCLA conference in 1994 (funnily he didn’t attend himself as he was busy getting married!) and now 20 years later he was being honoured with the accolade of being the BCLA Gold Medallist. The date of his BCLA medal addressed was shared with his father's birthday so a double celebration for Phil. Well done to outgoing BCLA President Andy Yorke and his team at the BCLA (including Nick Rumney, Cheryl Donnelly, Sarah Greenwood and Amir Khan) on an excellent conference. And finally welcome to new President Susan Bowers. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.
Resumo:
Nutrition is an important component in chronic disease prevention. Diet plays an important role in the athletic performance and the overall health of the amateur bicyclists; yet information concerning diet and amateur bicyclists is lacking. This was a cross-sectional, convenience sample of 125 amateur bicyclists ages 18-65 years from South Florida who consented to SurveyMonkey, web-designed survey on nutrition knowledge. The survey was validated for endurance runners. Less than one-quarter of the participants had adequate nutrition knowledge (score of 75% or higher). Female bicyclists scored higher on nutrition knowledge as compared to males. There were no differences in nutrition knowledge by race, marital status, education or income. Accessibility to nutrition information is abundant, yet the validity of this information is questionable. Amateur bicyclist may not have access to the health professionals available to professional athletes. There is a need for nutrition counseling targeting amateur athletes.
Resumo:
General note: Title and date provided by Bettye Lane.
Resumo:
The aim of this study was to map the age profile according to the sex of the runners who participated in the 41a Prova Rústica Tiradentes held in the city of Maringa-PR. This research was descriptive with a mixed approach. For data analysis, descriptive statistics (frequency and relative percentage) using the computerized statistical package SPSS version 20.0 was used. A total of 2609 runners completed the proof, 67.9 por ciento male and 32.0 por ciento female, what could show greater adherence of male runners, if compared with the female group. It is noteworthy that the age group from 30-34 years old was the most representative in both sexes. It was concluded that there was presence of runners in all categories offered in Prova Rústica Tiradentes, in both sexes; thus, the proof fulfills its social role of promotion the sport of participation, and especially enabling that a greater number of people participate.
Resumo:
The aim of this study was to map the age profile according to the sex of the runners who participated in the 41a Prova Rústica Tiradentes held in the city of Maringa-PR. This research was descriptive with a mixed approach. For data analysis, descriptive statistics (frequency and relative percentage) using the computerized statistical package SPSS version 20.0 was used. A total of 2609 runners completed the proof, 67.9 por ciento male and 32.0 por ciento female, what could show greater adherence of male runners, if compared with the female group. It is noteworthy that the age group from 30-34 years old was the most representative in both sexes. It was concluded that there was presence of runners in all categories offered in Prova Rústica Tiradentes, in both sexes; thus, the proof fulfills its social role of promotion the sport of participation, and especially enabling that a greater number of people participate.
Resumo:
Objectives
Barefoot running describes when individuals run without footwear. Minimalist running utilizes shoes aimed to mimic being barefoot. Although these forms of running have become increasingly popular, we still know little about how recreational runners perceive them.
Design
In-depth interviews with eight recreational runners were used to gather information about their running experiences with a focus on barefoot and minimalist running.
Methods
Interviews were analysed using a latent level thematic analysis to identify and interpret themes within the data.
Results
Although participants considered barefoot running to be ‘natural’, they also considered it to be extreme. Minimalist running did not produce such aversive reactions. ‘Support’ reassured against concerns and was seen as central in protecting vulnerable body parts and reducing impact forces, but lacked a common or clear definition. A preference for practical over academic knowledge was found. Anecdotal information was generally trusted, as were running stores with gait assessment, but not health professionals.
Conclusion
People often have inconsistent ideas about barefoot and minimalist running, which are often formed by potentially biased sources, which may lead people to make poor decisions about barefoot and minimalist running. It is important to provide high-quality information to enable better decisions to be made about barefoot and minimalist running.
Statement of contribution
What is already known on this subject?
There is no known work on the psychology behind barefoot and minimalist running. We believe our study is the first qualitative study to have investigated views of this increasingly popular form of running.
What does this study add?
The results suggest that although barefoot running is considered ‘natural’, it is also considered ‘extreme’. Minimalist running, however, did not receive such aversive reactions.
‘Support’ was a common concern among runners. Although ‘support’ reassured against concerns and was seen as central in protecting vulnerable body parts and reducing impact forces, it lacked a common or clear definition.
A preference for practical over academic knowledge was found. Anecdotal information was generally trusted, as were running stores with gait assessment, but not health professionals.
Resumo:
À la fin du 19e siècle, Dr. Ramón y Cajal, un pionnier scientifique, a découvert les éléments cellulaires individuels, appelés neurones, composant le système nerveux. Il a également remarqué la complexité de ce système et a mentionné l’impossibilité de ces nouveaux neurones à être intégrés dans le système nerveux adulte. Une de ses citations reconnues : “Dans les centres adultes, les chemins nerveux sont fixes, terminés, immuables. Tout doit mourir, rien ne peut être régénérer” est représentative du dogme de l’époque (Ramón y Cajal 1928). D’importantes études effectuées dans les années 1960-1970 suggèrent un point de vue différent. Il a été démontré que les nouveaux neurones peuvent être générés à l’âge adulte, mais cette découverte a créé un scepticisme omniprésent au sein de la communauté scientifique. Il a fallu 30 ans pour que le concept de neurogenèse adulte soit largement accepté. Cette découverte, en plus de nombreuses avancées techniques, a ouvert la porte à de nouvelles cibles thérapeutiques potentielles pour les maladies neurodégénératives. Les cellules souches neurales (CSNs) adultes résident principalement dans deux niches du cerveau : la zone sous-ventriculaire des ventricules latéraux et le gyrus dentelé de l’hippocampe. En condition physiologique, le niveau de neurogenèse est relativement élevé dans la zone sous-ventriculaire contrairement à l’hippocampe où certaines étapes sont limitantes. En revanche, la moelle épinière est plutôt définie comme un environnement en quiescence. Une des principales questions qui a été soulevée suite à ces découvertes est : comment peut-on activer les CSNs adultes afin d’augmenter les niveaux de neurogenèse ? Dans l’hippocampe, la capacité de l’environnement enrichi (incluant la stimulation cognitive, l’exercice et les interactions sociales) à promouvoir la neurogenèse hippocampale a déjà été démontrée. La plasticité de cette région est importante, car elle peut jouer un rôle clé dans la récupération de déficits au niveau de la mémoire et l’apprentissage. Dans la moelle épinière, des études effectuées in vitro ont démontré que les cellules épendymaires situées autour du canal central ont des capacités d’auto-renouvellement et de multipotence (neurones, astrocytes, oligodendrocytes). Il est intéressant de noter qu’in vivo, suite à une lésion de la moelle épinière, les cellules épendymaires sont activées, peuvent s’auto-renouveller, mais peuvent seulement ii donner naissance à des cellules de type gliale (astrocytes et oligodendrocytes). Cette nouvelle fonction post-lésion démontre que la plasticité est encore possible dans un environnement en quiescence et peut être exploité afin de développer des stratégies de réparation endogènes dans la moelle épinière. Les CSNs adultes jouent un rôle important dans le maintien des fonctions physiologiques du cerveau sain et dans la réparation neuronale suite à une lésion. Cependant, il y a peu de données sur les mécanismes qui permettent l'activation des CSNs en quiescence permettant de maintenir ces fonctions. L'objectif général est d'élucider les mécanismes sous-jacents à l'activation des CSNs dans le système nerveux central adulte. Pour répondre à cet objectif, nous avons mis en place deux approches complémentaires chez les souris adultes : 1) L'activation des CSNs hippocampales par l'environnement enrichi (EE) et 2) l'activation des CSNs de la moelle épinière par la neuroinflammation suite à une lésion. De plus, 3) afin d’obtenir plus d’information sur les mécanismes moléculaires de ces modèles, nous utiliserons des approches transcriptomiques afin d’ouvrir de nouvelles perspectives. Le premier projet consiste à établir de nouveaux mécanismes cellulaires et moléculaires à travers lesquels l’environnement enrichi module la plasticité du cerveau adulte. Nous avons tout d’abord évalué la contribution de chacune des composantes de l’environnement enrichi à la neurogenèse hippocampale (Chapitre II). L’exercice volontaire promeut la neurogenèse, tandis que le contexte social augmente l’activation neuronale. Par la suite, nous avons déterminé l’effet de ces composantes sur les performances comportementales et sur le transcriptome à l’aide d’un labyrinthe radial à huit bras afin d’évaluer la mémoire spatiale et un test de reconnaissante d’objets nouveaux ainsi qu’un RNA-Seq, respectivement (Chapitre III). Les coureurs ont démontré une mémoire spatiale de rappel à court-terme plus forte, tandis que les souris exposées aux interactions sociales ont eu une plus grande flexibilité cognitive à abandonner leurs anciens souvenirs. Étonnamment, l’analyse du RNA-Seq a permis d’identifier des différences claires dans l’expression des transcripts entre les coureurs de courte et longue distance, en plus des souris sociales (dans l’environnement complexe). iii Le second projet consiste à découvrir comment les cellules épendymaires acquièrent les propriétés des CSNs in vitro ou la multipotence suite aux lésions in vivo (Chapitre IV). Une analyse du RNA-Seq a révélé que le transforming growth factor-β1 (TGF-β1) agit comme un régulateur, en amont des changements significatifs suite à une lésion de la moelle épinière. Nous avons alors confirmé la présence de cette cytokine suite à la lésion et caractérisé son rôle sur la prolifération, différentiation, et survie des cellules initiatrices de neurosphères de la moelle épinière. Nos résultats suggèrent que TGF-β1 régule l’acquisition et l’expression des propriétés de cellules souches sur les cellules épendymaires provenant de la moelle épinière.
Resumo:
The aim of study was to examine the effects of the world's most challenging mountain ultramarathon (Tor des Geants [TdG]) on running mechanics. Mechanical measurements were undertaken in male runners (n = 16) and a control group (n = 8) before (PRE), during (MID), and after (POST) the TdG. Contact (tc) and aerial (ta) times, step frequency (f), and running velocity (v) were sampled. Spring-mass parameters of peak vertical ground-reaction force (Fmax), vertical downward displacement of the center of mass (Deltaz), leg-length change (DeltaL), and vertical (kvert) and leg (kleg) stiffness were computed. Significant decreases were observed in runners between PRE and MID for ta (P < .001), Fmax (P < .001), Deltaz (P < .05), and kleg (P < .01). In contrast, f significantly increased (P < .05) between PRE and MID-TdG. No further changes were observed at POST for any of those variables, with the exception of kleg, which went back to PRE. During the TdG, experienced runners modified their running pattern and spring-mass behavior mainly during the first half. The current results suggest that these mechanical changes aim at minimizing the pain occurring in lower limbs mainly during the eccentric phases. One cannot rule out that this switch to a "safer" technique may also aim to anticipate further damages.