• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 29
  • 17
  • 7
  • 7
  • 7
  • 7
  • 7
  • 7
  • 2
  • 1
  • Tagged with
  • 65
  • 65
  • 22
  • 18
  • 17
  • 15
  • 14
  • 13
  • 13
  • 10
  • 10
  • 10
  • 8
  • 8
  • 8
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Efeito do nível do treinamento aeróbio na determinação do limite superior do domínio pesado no ciclismo

Caritá, Renato Aparecido Corrêa [UNESP] 15 March 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-03-15Bitstream added on 2014-06-13T19:00:55Z : No. of bitstreams: 1 carita_rac_me_rcla.pdf: 596317 bytes, checksum: ae963e507d62f687b35122425b6c0d5b (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O principal objetivo deste estudo foi analisar e comparar as respostas metabólicas e cardiorrespiratórias durante o exercício realizado na MLSS e PC em indivíduos com diferentes níveis de treinamento aeróbio no ciclismo. Participaram do estudo 7 ciclistas (C) bem treinados, especializados em provas de estrada e 9 sujeitos não treinados (NT), sem experiência prévia de treinamento no ciclismo. Os voluntários realizaram em dias diferentes os seguintes testes, em um cicloergômetro: 1) teste incremental até a exaustão para a determinação do limiar anaeróbio (Lan), consumo máximo de oxigênio ( O2max) e da intensidade correspondente ao O2max (I O2max); 2) 2 a 4 testes de carga constante de 30 minutos em diferentes intensidades para a determinação da máxima fase estável de lactato sanguíneo (MLSS); 3) 3 testes de carga constante a 95, 100 e 110% I O2max até a exaustão voluntária para a determinação da potência crítica (PC), e; 4) um teste de carga constante até a exaustão na PC. A MLSS foi considerada como a maior intensidade de exercício onde a concentração de lactato não aumentou mais do que 1 mM entre o 10o e o 30o minuto de exercício. Os valores individuais de potência (95, 100 e 110% I O2max) e seu respectivo tempo máximo de exercício (tlim) foram ajustados a partir do modelo hiperbólico de 2 parâmetros para determinação da PC. A PC para ambos os grupos C (318 ± 29W) e NT (200 ± 33W) foi maior significantemente do que a MLSS para os C (288 ± 35W) e NT (169 ± 34W). A MLSS e a PC foram significantemente maiores no grupo C. Em valores relativos ao O2max a MLSS foi maior no grupo C (83 ± 7%) do que no grupo NT (79 ± 6), porém a PC foi similar entre os grupos (91 ± 5% e 90 ± 5%, respectivamente). Da mesma forma, o consumo de oxigênio na PC ( O2PC) foi significantemente maior do que na MLSS ( O2MLSS) nos grupos NT... / The objective of this study was to analyze and to compare metabolic and cardiorrespiratory responses durin the exercise performed at MLSS and CP in subjects with different aerobic trainning levels in cycling. Participated of this study, 7 well trained cyclists (C), specialized in road events and 9 non-trained subjects (NT), without previous training experience in cycling. Ths subjects performed the following protocols in different days in cyclergometer: 1) incremental test until exhaustion to determine anaerobic threshold (AT), maximal oxygen uptake ( O2max) and the intensity at O2max (I O2max); 2) 2 to 4 constant workload tests in different intensities to determine maximal lactate steadystate (MLSS); 3) 3 constant workload tests at 95, 100 e 110% I O2max until exhaustion to determine critical power (CP), and; 4) constant workload test until exhaustion at CP. MLSS was considered the highest exercise intensity at which the blood lactate concentration did not increase for more than 1 mM between 10th and 30th minute of the exercise. The individual values of power (95, 100 e 110% I O2max) and the respective times (tlim) were adjusted using the hyperbolic model with parameteres to determine CP. CP for C (318 ± 29W) and NT (200 ± 33W) was significantly higher than MLSS in C (288 ± 35W) and NT (169 ± 34W). MLSS and PC were significantly higher in C group. In values relative to O2max, the MLSS was significantly higher in C (83 ± 7%) than NT (79 ± 6), however CP was similar between groups (91 ± 5% and 90 ± 5%, respectively). In the same way, the oxygen uptake at CP ( O2PC) was significantly higher than at MLSS ( O2MLSS) for NT (2627 + 519 e 2323 ± 460 mL.min-1, 11%) e C (3607 ± 505 e 3953 ± 466 mL.min-1, 8%). The slow component at CP in C (375 ± 164 ml.min-1) was similar to NT (412 ± 175 ml.min-1). At this condition, the O2max was not attained (C – 93 ± 5%; NT – 96 ± 7%)... (Complete abstract click electronic access below)
52

The rolling resistances of roller skis and their effects on human performance during treadmill roller skiing

Ainegren, Mats January 2010 (has links)
<p>Modern ski-treadmills allow cross-country skiers, biathletes and ski-orienteers to test their physical performance in a laboratory environment using classical and freestyle techniques on roller skis. For elite athletes the differences in performance between test occasions are quite small, thus emphasising the importance of knowing the roller skis’ rolling resistance coefficient, µ<sub>R</sub>, in order to allow correct comparisons between the results, as well as providing the opportunity to study work economy between different athletes, test occasions and core techniques.</p><p>Thus, one of the aims of this thesis was to evaluate how roller skis’ µ<sub>R</sub> is related to warm-up, mass, velocity and inclination of the treadmill. It was also necessary to investigate the methodological variability of the rolling resistance measurement system, RRMS, specially produced for the experiments, with a reproducibility study in order to indicate the validity and reliability of the results.</p><p>The aim was also to study physiological responses to different µ<sub>R</sub> during roller skiing with freestyle and classical roller skis and techniques on the treadmill as a case in which all measurements were carried out in stationary and comparable conditions.</p><p>Finally, the aim was also to investigate the work economy of amateurs and female and male junior and senior cross-country skiers during treadmill roller skiing, i.e. as a function of skill, age and gender, including whether differences in body mass causes significant differences in external power per kg due to differences in the roller skis’ µ<sub>R</sub>.</p><p>The experiments showed that during a warm-up period of 30 minutes, µ<sub>R</sub> decreased to about 60-65% and 70-75% of its initial value for freestyle and classical roller skis respectively. For another 30 minutes of rolling no significant change was found. Simultaneous measurements of roller ski temperature and m<sub>R</sub> showed that stabilized m<sub>R</sub> corresponds to a certain running temperature for a given normal force on the roller ski. The study of the influence on m<sub>R</sub> of normal force, velocity and inclination produced a significant influence of normal force on m<sub>R</sub>, while different velocities and inclinations of the treadmill only resulted in small changes in m<sub>R</sub>. The reproducibility study of the RRMS showed no significant differences between paired measurements with either classical or the freestyle roller skis.</p><p>The study of the effects on physiological variables of ~50% change in µ<sub>R</sub>,<sub> </sub>showed that during submaximal steady state exercise, external power, oxygen uptake, heart rate and blood lactate were significantly changed, while there were non significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests showed that time to exhaustion was significantly changed and this occurred without a significantly changed maximal power, maximal oxygen uptake, maximal heart rate and blood lactate, and that the influence on ratings of perceived exertion was non significant or small.</p><p>The final part of the thesis, which focused on work economy, found no significant difference between the four groups of elite competitors, i.e. between the two genders and between the junior and senior elite athletes. It was only the male amateurs who significantly differed among the five studied groups. The study also showed that the external power per kg was significantly different between the two genders due to differences in body mass and m<sub>R</sub>, i.e. the lighter female testing groups were roller skiing with a relatively heavier rolling resistance coefficient compared to the heavier testing groups of male participants.</p> / Sporttech
53

Detecção do limiar de lactato salivar e da variabilidade da freqüência cardíaca em exercício resistido: comparação entre métodos.

Oliveira, João Carlos de 14 March 2007 (has links)
Made available in DSpace on 2016-06-02T19:22:47Z (GMT). No. of bitstreams: 1 1388.pdf: 1953339 bytes, checksum: 14b647b421ed18e30c83f687539d100f (MD5) Previous issue date: 2007-03-14 / Financiadora de Estudos e Projetos / Important researches had shown the benefits of resistance training programs for rehabilitation as well as prophylaxis of physical incapacity. However few studies had investigated the responses of the intermediate metabolism during the execution of resistance exercises if carried through steady state or during incremental tests. The purpose of this study was to investigate the viability of the use of non-invasive methods as trustworthy indicators in the analysis of the aerobic-anaerobic transition and to compare the physiological responses between male and female, submitted to discontinuous incremental test of resistance exercise for lower limb. Eighteen subjects volunteered to participate and provided a written consent (9 males, 24 ± 3 years, 176 ± 5 cm, 72 ± 10 kg and 9 females, 23 ± 2 years, 165 ± 6 cm, 59 ± 10 Kg) in two sessions, distinct days, of counterweighted isoinertial Leg Press 45º machine (LP), being the 1st session performed to identify the 1 repetition maximum load (1RM) and the 2nd to accomplish the discontinuous incremental test of the type step in LP (DIT). The loading gradual scheme was determined in relation to the percentage of 1RM (%1RM). Subjects were required to perform 20 ± 2 repetitions with a 2 minutes interval between each set when loads were changed and collection of blood and salivary samples were collected. The blood lactate concentration ([La-]) had been used as gold standard for the respective comparisons between the methods. As non-invasive methods the salivary lactate concentrations ([SL]) and index SD1 of the heart rate variability (HRV) were used, gotten by Poincaré Plotting (PP). The thresholds identified by [La-] and [SL] (LT and SLT, respectively) had been determined by Mader and Heck Method (1986). The threshold identified by index SD1 (SD1T) was determined by Tullpo et al. (1998) criterion. The criterion level for statistical significance was set at an alpha level of p< 0,05. Statistical differences had not been found in the comparisons between genders in each step of the DIT for the three variables studied. The thresholds when expressed in kg revealed significant differences between genders but not intra genders. When expressed in %1RM the thresholds had been placed in the average enter 29-40% and had not evidenced significant differences between the thresholds in the conditions intra genders and between genders. Correlations of 0.89 and 0.78 had been evidenced between the LT and SLT and SD1T, respectively. The variability of both non-invasive variables was shown inside of the limits of agreement evidenced by the analyses of Bland-Altman. Thus it is possible to conclude that as much the SL as index SD1 of HRV responses of similar form to the blood lactate. This allows the detention of the thresholds of lactate salivary and heart rate variability, independently of the gender. In this way, as much the SL as index SD1 of the HRV presents great potential as possible non invasive markers of effort intensity, that they can be used in the lapsing and the control of the load of work in the resistance exercises. Moreover, the differences in the metabolic responses between the genders, evidenced in the intensities of effort above of the threshold, must be considered in the lapsing of the resistance training. / Importantes trabalhos têm relatado os benefícios dos programas de treinamento resistido tanto para a reabilitação como para profilaxia de incapacidade física. Contudo poucos foram os estudos que investigaram as respostas do metabolismo energético intermediário durante a execução de exercícios resistidos, fossem eles realizados em estado estável ou durante testes incrementais. Assim o propósito deste estudo foi o de investigar a viabilidade da utilização de métodos não invasivos, como indicadores confiáveis na análise da transição do metabolismo aeróbio-anaeróbio, e comparar as respostas fisiológicas entre homens e mulheres, submetidos a teste incremental descontínuo do tipo degrau em exercício resistido de membros inferiores. Para isso dezoito jovens saudáveis (9 homens, 24,22 ± 2,77 anos, 175,89 ± 4,99 cm, 71,73 ± 9,81 kg e 9 mulheres, 22,64 ± 1,87 anos, 164,89 ± 5,30 cm, 58,61 ± 9,58 kg) foram voluntários em duas sessões de exercício resistido no Leg Press 45° isoinércio (LP), em dias distintos, sendo a 1ª sessão para a determinação da carga máxima dinâmica para uma repetição (CMD) e a 2ª para a realização de teste incremental descontínuo do tipo degrau no LP (TILP). O esquema progressivo das cargas foi determinado em relação ao percentual da CMD (%CMD) e conduzido até exaustão voluntária. Os sujeitos realizavam 20±2 repetições, com intervalo de 2 minutos entre cada série onde eram trocadas as cargas e efetuadas as coletas das amostras sangüíneas e salivares. As concentrações de lactato sangüíneo [La-] foram utilizadas como padrão ouro para as respectivas comparações entre os métodos. Como métodos não invasivos utilizaram-se as concentrações de lactato salivar [LS] e o índice SD1 da variabilidade da freqüência cardíaca (VFC), obtido pela plotagem de Poincaré (PP). Os limiares identificados pelas [La-] e [LS] (LL e LLS, respectivamente) foram determinados pelo método propostos por Mader e Heck (1986). O limiar do índice SD1 (LSD1) foi determinado pelo critério proposto por Tullpo et al. (1998). O índice de significância adotado foi de 5% e o grau de confiabilidade de 95%. Não foram encontradas diferenças estatísticas significantes nas comparações entre gênero em cada estágio do TILP para as três variáveis estudadas. Os limiares quando expressos em kg mostraram-se diferentes estatisticamente entre gêneros, mas não intra-gênero. Quando expressos em %CMD os limiares situaram-se na média entre 29% a 40% e não foram evidenciadas diferenças significantes entre os limiares nas condições intra gênero e entre gênero. Correlação de moderada a forte (0,89 e 0,78) foi encontrada entre os LL e os LLS e LSD1, sendo ambos concordantes, como ficou evidenciado pelas análises de Bland-Altman. Assim os resultados sugerem que tanto o LS como o índice SD1 respondem de forma semelhante ao La-, o que permite a identificação na mudança do padrão de resposta cinética de tais variáveis, independentemente do gênero. Desta maneira, tanto o LS como o índice SD1 da VFC apresentam grande potencial como métodos alternativos não invasivos de intensidade de esforço, que podem ser usados na prescrição e no controle da carga de trabalho nos exercícios resistidos. Além disso, há diferenças entre os gêneros nas respostas metabólicas nas intensidades de esforço acima do limiar que devem ser consideradas na prescrição do treinamento resistido.
54

Spirulina e exercício na recuperação de ratos submetidos à desnutrição protéica /

Voltarelli, Fabricio Azevedo. January 2008 (has links)
Orientador: Maria Alice Rostom de Mello / Banca: Eliete Luciano / Banca: Renato Rocha / Banca: Julio Wilson dos Santos / Banca: Ricardo José Gomes / Resumo: A desnutrição protéica é, ainda, hoje, grave problema médico-social nos países em desenvolvimento. Assim, é de grande interesse o desenvolvimento de procedimentos mais efetivos no seu tratamento. Isso inclui o emprego do exercício físico bem como de novas fontes de proteína na alimentação. O presente estudo visou avaliar os efeitos da spirulina como fonte protéica, associada ou não ao exercício físico, sobre o crescimento e o metabolismo protéico muscular de ratos em recuperação da desnutrição protéica. Foram utilizados ratos Wistar, jovens (30 dias), separados nos seguintes grupos, de acordo com a fonte e a quantidade de proteína na dieta: I- Caseína 17% dos 30 aos 150 dias de idade; II- Spirulina 17% dos 30 aos 150 dias de idade; III- Caseína 6% dos 30 aos 150 dias de idade; IV- Caseína 6% dos 30 aos 90 dias e Spirulina 17% dos 91 aos 150 dias de idade; V- Caseína 6% dos 30 aos 90 dias e Caseína 17% dos 91 aos 150 dias de idade. Aos 91 dias, metade dos animais de cada grupo foi submetida ao treinamento físico de natação, 1 hora/dia, 5 dias/semana, durante 8 semanas, com sobrecarga equivalente à transição metabólica aeróbio/anaeróbio determinada pelo teste do lactato mínimo. No músculo sóleo foram determinados peso e teores de proteína total e de DNA para inferir sobre o crescimento. Como índices do metabolismo protéico muscular, foram avaliadas as taxas de síntese (incorporação de 14C fenilalanina) e degradação (liberação de tirosina) de proteínas bem como a expressão da proteína miosina (western blotting). A spirulina provou ser uma fonte protéica adequada para animais submetidos ou não à desnutrição... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: As we enter the 21st century and the new millennium, malnutrition remains the single most important factor impairing health and productivity of large human populations, mainly in the developing countries. For this reason, the exploration of alternative alimentary protein sources became a matter of generalized interest and may be, or not, associated to physical exercise. The present study verified the effects of the blue green alga spirulina as the dietary source of protein, associated or not to physical exercise, on growing and protein metabolism in skeletal muscle of young rats recovering from malnutrition. Young male wistar rats were separated into groups, according to diet protocol: Casein 6% from 30 to 150 days old; Spirulina 17% from 30 to 150 days; Casein 17% from 30 to 150 days; Casein 6% from 30 to 90 days and Spirulina 17% from 91 to 150 days and Casein 6% from 30 to 90 days and Casein 17% from 91 to 150 days. At 91 days, 50% of the animals of each group was submitted to swimming physical training, 1 hour/day, 5 days/week, during 8 weeks, supporting overload equivalent to aerobic/anaerobic metabolic transition determined by lactate minimum test. Spirulina proved to be an adequate protein source for animals submitted or not to protein malnutrition. This quality could be demonstrated by the maintenance of body length and weight of young animals fed the balanced diet containing spirulina. Considering the analysis of the muscle protein metabolism, the rates of protein synthesis and the expression... (Complete abstract click electronic access below) / Doutor
55

Comparação do custo energético, pico do lactato sanguíneo, percepção subjetiva do esforço e atividade eletromiográfica nos exercícios resistidos em plataformas estável e instável

Aranda, Liliane Cunha 03 June 2015 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-05-09T15:15:18Z No. of bitstreams: 1 lilianecunhaaranda.pdf: 1248132 bytes, checksum: a0aa518814e1294a6d9eca11f4e4bb1f (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-06-08T15:59:09Z (GMT) No. of bitstreams: 1 lilianecunhaaranda.pdf: 1248132 bytes, checksum: a0aa518814e1294a6d9eca11f4e4bb1f (MD5) / Made available in DSpace on 2016-06-08T15:59:09Z (GMT). No. of bitstreams: 1 lilianecunhaaranda.pdf: 1248132 bytes, checksum: a0aa518814e1294a6d9eca11f4e4bb1f (MD5) Previous issue date: 2015-06-03 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O impacto metabólico no custo energético (CE) dos exercícios resistidos (ER) é pouco conhecido na literatura científica. As diversas possibilidades de organização do treino, utilização de diferentes plataformas instáveis (PI), a atividade eletromiográfica (EMG) e a medida do componente anaeróbio no CE que muitas vezes é desprezada nos estudos sobre ER, podem alterar o valor do CE. O presente estudo teve como objetivos: 1) comparar o efeito agudo dos ER no método de treinamento circuitado (MTC) em plataformas estáveis (PE) e PI sobre o CE, pico do lactato sanguíneo (PLS) e percepção subjetiva do esforço (PSE); 2) comparar a atividade EMG e a força em 15 repetições máximas no supino reto e agachamento livre em PE e PI. A amostra foi composta de 20 homens saudáveis (24,65 ± 3,48 anos, 1,79 ± 0,08 m, 80,61 ± 9,14 Kg e 11,86 ± 3,49 % de gordura). No primeiro estudo propusemos um circuito com sete ER em PE e PI. Encontramos um CE total maior em PI vs. PE (p=0,01), assim como a PSE total (p=0,02), entretanto o PLS foi maior em PE vs. PI (p=0,05). Conclui-se que o uso das PI no MTC é uma excelente alternativa para os indivíduos que buscam uma maior demanda energética nos ER. No segundo estudo verificamos que o valor da carga levantada para o agachamento livre na PE foi significativamente superior em relação a PI (p=0,001), diferença esta não encontrada no supino reto (p=0,231). Em relação à atividade EMG, não foram observadas diferenças significativas no deltoide anterior (p=0,06), peitoral maior (p=0,14), bíceps femoral (p=0,50) e vasto lateral (p=0,76) em ambas as plataformas. As PI produzem uma similar atividade EMG em relação às PE mesmo utilizando uma menor carga. / The metabolic impact on energy cost (EC) of resistance exercise (RE) is little known to date in the scientific literature. The various possibilities for organizing training, using different unstable surfaces (US), electromyographic (EMG) activity and the measurement of the anaerobic component in EC, which is often overlooked in studies on RE, can change the value of EC. This study aimed to: 1) compare the acute effect of RE on the circuit training method (CTM) in stable surfaces (SS) and US on the EC, peak blood lactate (PBL) and perceived exertion (PE); 2) compare the EMG activity and strength in 15 repetition maximum bench press and squat free PE and PI. The sample consisted of 20 healthy men (24.65 ± 3.48 years old, 1.79 ± 0.08 m, 80.61 ± 9.14 kg and 11.86 ± 3.49% fat). In the first study we proposed a circuit with seven RS on a SS and an US. We found a higher total EC on US vs. SS (p = 0.01) and total PE (p = 0.02), but the PBL was higher on the SS vs. the US (p = 0.05). We can conclude that the use of US in the CTM is a great alternative for individuals seeking greater energy demand in the RE. In the second study, it was found that the value of the load lifted in the free squat on the SS was significantly higher than on the US (p = 0.001), a difference not found in the bench press (p = 0.231). Regarding the EMG activity, no significant differences were observed in the anterior deltoid (p = 0.06), pectoralis major (p = 0.14), biceps femoris (p = 0.50) and vastuslateralis (p = 0.76) on both surfaces. The US produces a similar EMG activity in relation to SS even using a lower load.
56

Relationship between lactate values and mortality in patients with haemorrhagic shock in an emergency unit

Zarrabi, Eleonora Natali 23 November 2011 (has links)
Introduction : Trauma is the leading cause of death in patients between the ages of 1-44 years in South Africa. Taking these statistics into consideration it is essential to better resuscitation strategies in order to improve outcome of trauma patients. Compensated and uncompensated haemorrhagic shock is frequently under diagnosed in trauma patients, which has a definitive effect on mortality. Concerns about inadequate monitoring of patients through the use of only physiological end points are raised. Methods : A comprehensive literature review was conducted on resuscitation strategies for patients presenting with haemorrhagic shock. Physiological and metabolic end points of resuscitation were identified to guide resuscitation strategies. A quantitative, retrospective, non-experimental, descriptive, correlational and crosssectional research design was chosen for this study. Data was collected by using biophysical measures, namely clinical audit checklists. Results : Lactate was identified as a good indicator to predicting mortality in patients presenting with shock caused by haemorrhage. Special consideration to patients’ age and physiological status should be made during resuscitation. The consequence of delayed resuscitation in haemorrhagic shock patients is associated with an increase in mortality that can be prevented. It is found that serum blood lactate levels taken over time are good predictors of patient survival rates. Patients presenting with a raised serum blood lactate level for more than 24-hours has an increase in mortality rate. Conclusion : Emergency nurse practitioners are responsible for the monitoring of patients admitted to the emergency unit with haemorrhagic shock. The use of serum lactate levels during the first 24-hours of the resuscitation of patients with haemorrhage can assist with the implementation of strategies to reverse the effect haemorrhagic shock on cellular level in these patients. / Dissertation (MCur)--University of Pretoria, 2011. / Nursing Science / unrestricted
57

Investigations for the Development of a Physiological Profile in Women's Soccer

Martinez Lagunas, Vanessa 17 July 2018 (has links)
The present PhD thesis is compilation of various investigations for the development of a physiological profile in women’s soccer. After an extensive literature review, several literature gaps in this area were identified including: physiological demands of a women’s soccer match including simultaneous measurements with portable metabolic equipment and GPS technology; physical performance analysis of women’s soccer competitive matches of different competition levels using GPS technology; and fitness testing and fitness profiles of female soccer players of different competitive levels by means of laboratory and field tests. The investigations that are part of this thesis targeted these gaps and provided for the first time novel and objective findings in these subjects. The popularity of women’s soccer as well as the number of female soccer players worldwide has increased exponentially in the last 30 years. Furthermore, there are now multiple women’s soccer international competitions and professional leagues around the globe and they will continue to increase in the next few years. Therefore, there is currently high demand for scientific research specific to the women’s game in these topics which may aid coaches, physical trainers, and other practitioners to develop more effective fitness assessments and training programs for their female players in order to improve their fitness status and overall match performance according to their competitive level and positional role.:DEDICATION iii ACKNOWLEDGMENTS iv BIBLIOGRAPHICAL INFORMATION vi ABSTRACT vii LIST OF PUBLICATIONS viii TABLE OF CONTENTS ix LIST OF TABLES xi LIST OF FIGURES xii LIST OF ABBREVIATIONS xiii 1 INTRODUCTION 1 1.1. WOMEN’S SOCCER BACKGROUND 1 1.2. PHYSICAL AND PHYSIOLOGICAL CHARACTERISTICS OF FEMALE SOCCER PLAYERS 3 1.3. PHYSICAL AND PHYSIOLOGICAL DEMANDS OF WOMEN’S SOCCER 4 2 DISSERTATION AIMS 6 3 STATE OF THE ART 8 3.1. PORTABLE METABOLIC, HEART RATE AND BLOOD LACTATE MEASUREMENTS 8 3.2. GLOBAL POSITIONING SYSTEM (GPS) MEASUREMENTS 9 3.3. TEST PROTOCOLS 10 3.3.1. ANTHROPOMETRY ASSESSMENT 10 3.3.2. AEROBIC CAPACITY TESTS 11 3.3.3. SPEED, ANAEROBIC ABILITY AND EXPLOSIVE POWER TESTS 15 4 OWN AREAS OF RESEARCH 18 4.1. PHYSIOLOGICAL DEMANDS OF A WOMEN’S FOOTBALL MATCH (ENGLISH SUMMARY FROM “PHYSIOLOGISCHE BEANSPRUCHUNG EINES FRAUENFUẞBALLSPIELS)” – (P-I) 18 4.2. GPS PERFORMANCE ANALYSIS OF WOMEN’S SOCCER COMPETITIVE MATCHES OF THE SECOND AND FOURTH GERMAN LEAGUES – (P-IV) 21 4.3. VALIDITY OF THE YO-YO INTERMITTENT RECOVERY TEST LEVEL 1 FOR DIRECT MEASUREMENT OR INDIRECT ESTIMATION OF MAXIMAL OXYGEN UPTAKE AMONG FEMALE SOCCER PLAYERS – (P-II) 25 4.4. FITNESS PROFILES OF GERMAN FEMALE SOCCER PLAYERS (UNPUBLISHED RESULTS) 26 5 CONCLUSIONS AND OUTLOOK 31 5.1. MAIN FINDINGS 31 5.2. PRACTICAL APPLICATIONS 33 5.3. STRENGTHS AND LIMITATIONS 33 5.4. FUTURE DIRECTIONS 34 6 REFERENCES 36 EIGENSTÄNDIGKEITSERKLÄRUNG 39 AUTHOR’S RESUME 40 ORIGINAL PUBLICATIONS 42 PUBLICATION 1 (P-I) 43 PUBLICATION 2 (P-II) 50 PUBLICATION 3 (P-III) 58 PUBLICATION 4 (P-IV) 74
58

The rolling resistances of roller skis and their effects on human performance during treadmill roller skiing

Ainegren, Mats January 2010 (has links)
Modern ski-treadmills allow cross-country skiers, biathletes and ski-orienteers to test their physical performance in a laboratory environment using classical and freestyle techniques on roller skis. For elite athletes the differences in performance between test occasions are quite small, thus emphasising the importance of knowing the roller skis’ rolling resistance coefficient, µR, in order to allow correct comparisons between the results, as well as providing the opportunity to study work economy between different athletes, test occasions and core techniques. Thus, one of the aims of this thesis was to evaluate how roller skis’ µR is related to warm-up, mass, velocity and inclination of the treadmill. It was also necessary to investigate the methodological variability of the rolling resistance measurement system, RRMS, specially produced for the experiments, with a reproducibility study in order to indicate the validity and reliability of the results. The aim was also to study physiological responses to different µR during roller skiing with freestyle and classical roller skis and techniques on the treadmill as a case in which all measurements were carried out in stationary and comparable conditions. Finally, the aim was also to investigate the work economy of amateurs and female and male junior and senior cross-country skiers during treadmill roller skiing, i.e. as a function of skill, age and gender, including whether differences in body mass causes significant differences in external power per kg due to differences in the roller skis’ µR. The experiments showed that during a warm-up period of 30 minutes, µR decreased to about 60-65% and 70-75% of its initial value for freestyle and classical roller skis respectively. For another 30 minutes of rolling no significant change was found. Simultaneous measurements of roller ski temperature and mR showed that stabilized mR corresponds to a certain running temperature for a given normal force on the roller ski. The study of the influence on mR of normal force, velocity and inclination produced a significant influence of normal force on mR, while different velocities and inclinations of the treadmill only resulted in small changes in mR. The reproducibility study of the RRMS showed no significant differences between paired measurements with either classical or the freestyle roller skis. The study of the effects on physiological variables of ~50% change in µR,showed that during submaximal steady state exercise, external power, oxygen uptake, heart rate and blood lactate were significantly changed, while there were non significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests showed that time to exhaustion was significantly changed and this occurred without a significantly changed maximal power, maximal oxygen uptake, maximal heart rate and blood lactate, and that the influence on ratings of perceived exertion was non significant or small. The final part of the thesis, which focused on work economy, found no significant difference between the four groups of elite competitors, i.e. between the two genders and between the junior and senior elite athletes. It was only the male amateurs who significantly differed among the five studied groups. The study also showed that the external power per kg was significantly different between the two genders due to differences in body mass and mR, i.e. the lighter female testing groups were roller skiing with a relatively heavier rolling resistance coefficient compared to the heavier testing groups of male participants. / Sporttech
59

Determinação das zonas de transição metabólica durante a corrida mediante os limiares de variabilidade da frequência cardíaca / Determination of transition metabolic zones during running using hert rate variability thresholds

Nascimento, Eduardo Marcel Fernandes 17 January 2011 (has links)
O propósito do presente estudo foi obter evidências de validade e reprodutibilidade dos limiares de variabilidade da frequência cardíaca (VFC) durante a corrida. Dezenove sujeitos homens, saudáveis e praticantes de corrida (30,4 ± 4,1 anos; 175,9 ± 6,4 cm; 74,3 ± 8,5 kg) foram submetidos a um teste progressivo máximo em esteira rolante com velocidade inicial 5 km.h-1 e incrementos de 1 km.h-1 a cada 3 minutos (1% de inclinação constante) até exaustão voluntária. Todos os indivíduos realizaram o reteste em um intervalo de tempo entre 48 horas e uma semana. Foram realizadas as medidas das trocas gasosas, do lactato sanguíneo e da VFC (plotagem de Poincaré). Os limiares aeróbio (LAe) e anaeróbio (LAn) foram determinados pelos limares de lactato, ventilatórios e da VFC. Para a comparação entre os métodos foi uitlizada ANOVA para medidas repetidas, acompanhada de teste de post hoc de Bonferroni. A reprodutibilidade das variáveis analisadas foram verificadas pela plotagem de Bland-Altman e pelo coeficiente de correlação intraclasse (CCI). Os resultados do presente estudo demonstraram que a velocidade correspondente ao segundo e terceiro modelos utilizados para se determinar o LA pela VFC não eram significativamente diferentes (p > 0,05) do primeiro limiar de lactato e ventilatório. Em relação ao LAn, não foram observadas diferenças significativas nas velocidades correspondentes ao LAn detectado pelos diferentes métodos (p > 0,05). Os valores do CCI estavam entre 0,69 a 0,80 (p < 0,001). Conclui-se que o LAe e o LAn podem ser identificados pela análise da VFC, desde que se utilize os procedimentos empregados na presente investigação / The aim of the present study was to obtain evidences of validity and reliability of the thresholds of heart rate variability (HRV). Nineteen male subjects, healthy and runners (30,4 ± 4,1 years; 175,9 ± 6,4 cm; 74,3 ± 8,5 kg) performed a progressive maximal test on a treadmill with initial velocity 5 km.h-1 e increases of 1 km.h-1 every 3 minutes (1% slope) until voluntary exhaustion. All subjects performed the retest at an interval of time between 48 hours and one week. It was measured gas exchange, blood lactate and heart rate variability (Poincaré plot). The aerobic threshold (AT) and anaerobic (AnT) were determined by lactate, ventilatory and heart rate variability. ANOVA for repeated measures and post-hoc test of Bonferroni was used to compare the methods. To analyze the reproducibility of the variables were used the Bland- Altman plots and intraclass correlation coefficient (ICC). The results of this study show that the velocity at the second and third models employed to determine the AT by HRV were not significantly different (p > 0.05) of the first lactate threshold and ventilatory. Similarly, there were no significant differences in the velocities corresponding to AnT detected by different methods (p> 0.05). The ICC values were between 0.69 to 0.80 (p < 0.001). We conclude that the AT and the AnT can be estimated by HRV analysis, since it utilizes the procedures employed in this study
60

Impacto de 4 semanas de treinamento intervalado de alta intensidade sobre variáveis fisiológicas determinantes da aptidão aeróbia e a estratégia de corrida adotada durante um teste contra-relógio de 5 km / Impact of 4-weeks high intensity interval training program over physiological variables determinants of endurance performance and over pacing strategy adopted during a 5-km time-trial test

Silva, Rogerio Carvalho da 09 December 2013 (has links)
Estratégia de corrida é forma pela qual os corredores distribuem a velocidade durante uma competição. Objetivando otimizar a utilização dos recursos energéticos, bem como melhorar o desempenho geral na prova, durante uma corrida de 5 km os atletas comumente adotam uma estratégia caracterizada por um início em alta velocidade, seguido por um trecho intermediário em velocidade inferior, e finalmente os atletas aumentam a velocidade quando se aproximam dos 400 m finais da prova. Sabe-se que o treinamento intervalado de alta intensidade (TIAI) realizado ao longo de 3 a 6 semanas é capaz de promover melhoras significativas nas variáveis fisiológicas determinantes do desempenho aeróbio, tais como VO2max, EC, VP, e OBLA. Uma vez que os atletas monitoram a PSE baseado em sinais internos (fisiológicos) e externos (ambiente), e desta forma alteram a velocidade para evitarem o término prematuro do exercício, acredita-se que melhoras em tais variáveis fisiológicas possam permitir que os corredores modifiquem a estratégia de corrida. Portanto, o principal objetivo do presente estudo foi analisar a influência de quatro semanas de TIAI sobre a PSE e também sobre a estratégia de corrida adotada por corredores durante um teste contra-relógio de 5 km (T5). Vinte sujeitos, homens, corredores recreacionais de longa distância foram distribuídos de forma contrabalançada em grupo controle (CON, n = 10; 33,5 ± 6,2 anos) e grupo treinamento intervalado (TINT, n = 10; 32,9 ± 8,6 anos). TINT realizou uma sessão de TIAI duas vezes por semana, enquanto que CON manteve seu programa regular de treinamento. Antes e após o período de intervenção, os corredores realizaram: 1) um teste incremental até exaustão para se obter o início do acúmulo de lactato sanguíneo (OBLA), o consumo máximo de oxigênio (VO2max), e a velocidade pico em esteira (VP); 2) um teste submáximo de carga constante para se medir a economia de corrida (EC); 3) e um teste contra-relógio de 5 km (T5) em pista para se estabelecer a estratégia de corrida. O programa de TIAI produziu uma melhora relevante no VO2max (effect size = 0,219), OBLA (effect size = 0,489), EC (effect size = -0,593), e VP (effect size = 0,622). Não foram detectadas alterações significativas na estratégia de corrida, TT5, VT5 e PSET5 durante o T5, comparando ambas as condições (pré e pós-treinamento) ou entre os grupos (TINT e CON; P > 0,05). Esses achados sugerem que melhoras nas variáveis fisiológicas induzidas por um programa de quatro semanas de TIAI não são acompanhadas por alterações similares na PSE e na estratégia de corrida durante um teste contra-relógio de 5 km / Pacing strategy has been defined as the manner by which the runners distribute their speed during a competition. In order to optimize the use of the energetic resources, as well as improve the general race performance, during a 5-km running race, athletes usually adopt a pacing strategy characterized by a fast start (400 m), followed by a period of slower speed during the middle (400 4600 m), and a significant increase in running speed during the last part of the race (400 m). It is well recognized that high-intensity interval training (HIIT) performed along 3 to 6 weeks is able to promote significant improvements in physiological variables determinants of endurance performance, such as VO2max, RE, PTS, and OBLA. Since athletes monitor their RPE based on the internal (physiological) and external (environment) signals, and change their running speed in order to prevent a premature exercise termination, its believed that improvements in such physiological variables could enable athletes to modify the pacing strategy. Thus, the main purpose of this study was to analyze the influence of 4 weeks of high-intensity interval training (HIIT) on the rating of perceived exertion (RPE) and the pacing strategy adopted by runners during a 5-km running time-trial (T5). Twenty male, recreational long-distance runners were randomly assigned into control group (CG, n = 10) or high-intensity interval-training group (HIITG, n = 10). The HIITG performed a high-intensity interval-training session twice per week, while CG maintained its regular training program. Before and after the training period, the runners performed the following tests: 1) an incremental exercise test to exhaustion to measure the onset of blood lactate accumulation (OBLA), maximal oxygen uptake (VO2max), and peak treadmill speed (PTS); 2) a submaximal speed-constant test to measure the running economy (RE); 3) a 5-km running time-trial on an outdoor track to establish pacing strategy. HIIT program produced a relevant improvement on the VO2max (effect size = 0.219), OBLA (effect size = 0.489), RE (effect size = -0.593), and PTS (effect size = 0.622). There were no significant differences on pacing strategy, TT5, ST5 and RPE response during the 5-km running time-trial between both conditions (pre- and post-training) or between groups (HIITG and CG; P > 0.05). These findings suggest that improvements on the physiological variables induced by a 4-week HIIT program are not accompanied by similar modifications on the RPE and running pacing strategy during a 5-km running time-trial

Page generated in 0.0689 seconds