O presente estudo teve por objetivo caracterizar em atletas homens e mulheres a dinâmica do stiffness e dos parâmetros biomecânicos atrelados ao stiffness (PBAS) durante uma corrida de elevada velocidade e curta duração. Ainda, investigar possíveis discriminantes de desempenho da corrida, e a relação destes com as tarefas de salto frequentemente utilizados nos treinamentos. Para tanto, foram realizados 2 estudos, sendo que o estudo 1 caracterizou a dinâmica dos parâmetros biomecânicos atrelados ao stiffness e apontou possíveis discriminantes de desempenho (por gênero), e no estudo 2 relacionou-se estes possíveis discriminantes com as tarefas de salto. O \"Spring Mass Model\" foi utilizado para obtenção dos PBAS, ao ponto que plataformas de força (AMTI) e a cinemetria (VICON) foram utilizados para a aquisição dos dados de salto. Foi evidenciado que o stiffness não apresentou total convergência com a dinâmica da velocidade apresentada no teste de corrida de elevada velocidade e curta duração, e que a força vertical aplicada ao solo durante a fase de apoio foi o PBAS que mais se aproximou da dinâmica apresentada pela velocidade. Não houveram distinções entre os gêneros na dinâmica do stiffness e dos PBAS, porém o gênero feminino apresentou maior dependência de parâmetros temporais de passo no início do teste e complacência muscular no final do teste, e o gênero masculino maior dependência de parâmetros atrelados a incremento de força no início do teste e incremento da fase aérea no final do teste. Ainda, houve diferença com significância estatística entre os gêneros quanto à magnitude e contribuição das fases da corrida. No mais, o salto horizontal (SH) apresentou maior relação com o desempenho em ambos os gêneros. Desta forma, conclui-se que 1) o stiffness propriamente dito não pode explicar o desempenho em uma corrida de elevada velocidade e curta duração, 2) dentre os PBAS, a magnitude da força vertical aplicada ao solo durante a fase de apoio apresentou maior proximidade com a dinâmica da velocidade, 3) homens e mulheres dependem distintamente dos PBAS para melhora no desempenho na corrida, e 4) o SH é meio de maior validade ecológica a ser utilizado nas rotinas de avaliação e treinamento de atletas envolvidos em provas de elevada velocidade e curta duração / The present study aims to characterize the dynamics of stiffness and biomechanical parameters related to stiffness (BPRS) in male and female athletes during top speed short distance run. It also intends to investigate possible performance discriminative factors and their relation with jumping tasks frequently used in training. For this purpose, two studies have been developed. Study 1 has characterized the dynamics of the biomechanical parameters related to stiffness and indicated possible discriminative factors (by gender). The study 2 has related these possible discriminative factors with jumping. The \'Spring Mass Model\' has been used to obtain the BRPS and the force plate (AMTI) and cinemetry (VICON) have been used to acquire jumping data. The study showed that stiffness has not presented total convergence with velocity dynamics and the vertical force applied to the ground during the support phase has been the closest result to the velocity dynamics presented. There has not been distinctions regarding gender in stiffness and BRPS dynamics, however, females have showed more dependency on step timing parameters on the test beginning and muscle complacency at the end of the test; and males presented more dependency on to the vertical force applied to the ground during the support phase on the test beginning and parameters connected to the increase in the swing phase at the end test. Moreover, there has been a difference with statistical significance between genders regarding magnitude and contribution through the running phases. In additional, the horizontal jump (HJ) results represented a closer relation to the performance top speed short distance run. Therefore, it has been concluded that 1) stiffness itself cannot explain the performance in top speed short distance run, 2) among the BRPS, vertical force magnitude applied to the ground during support phase presents closer results to velocity dynamics, 3) males and females depend on distinct BRPS to enrich their performance and 4) HJ is the exercise with the major validity to be used for the evaluation and training routine of top speed short distance run athletes

Made available in DSpace on 2014-06-11T19:30:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-12-11Bitstream added on 2014-06-13T19:19:34Z : No. of bitstreams: 1 belli_t_dr_rcla.pdf: 599166 bytes, checksum: 179b031df699228950b3f39e875ed73b (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A presente tese de doutorado teve por objetivo analisar as respostas inflamatória, hematológica, de estresse oxidativo, prejuízo muscular e composição corporal e suas possíveis relações com a performance em participantes de ultramaratona de 217 km. Para tanto, 11 atletas (42,6±6,2 anos; 170,4±1,9 cm de estatura; 70,7±3,1 kg de massa corporal; 16±3 anos de treinamento de corrida; 122±18km/semana de volume de treinamento) determinaram a velocidade crítica (CV) uma semana antes da prova e foram submetidos à coletas de sangue, avaliações antropométricas e relataram sua dor antes, durante e após a ‘Brazil 135 Ultramarathon’. Os voluntários completaram a prova em 46,6±3,1h, com uma velocidade média de 4,9±0,3km/h (34,5±1,9% da CV) e com 3,7±0,9h de tempo de pausa. Em relação às respostas inflamatórias e hematológicas, os valores de leucócitos, neutrófilos, monócitos, proteína C reativa, hemoglobina corpuscular média, concentração de hemoglobina corpuscular média e plaquetas aumentaram e de basófilos reduziram pré versus pós-prova (P<0,05). Além disso, os valores pós-prova de leucócitos e neutrófilos foram correlacionados (P<0,05) com velocidade média (R=0,70; 0,76, respectivamente), velocidade relativa à CV (%CV) (R=0,92; 0,96, respectivamente) e tempo de pausa (R=-0,66; -0,69, respectivamente). Já em relação às respostas de prejuízo muscular e estresse oxidativo, as concentrações de creatina quinase, lactato desidrogenase, aspartato aminotransferase, alanina aminotransferase e albumina bem como a dor muscular reportada pelos atletas aumentaram (P<0,05) enquanto a atividade da catalase, glutationa redutase (GR) e teores de urato permaneceram estáveis (P>0,05) durante a corrida. As concentrações circulantes de enzimas de dano muscular pós-prova foram correlacionados... / The aim of this study was analyzed inflammation, hematological parameters, oxidative stress, muscle damage and body composition in participants of 217-km ultramarathon. Furthermore, we hypothesized that these responses would be correlated to exercise performance during this race. Thus, 11 athletes (42.6±6.2 years; 170.4±1.9 cm height; 70.7±3.1 kg body weight; 16±3 years of race training; 122±18km/week of training volume) individually determined the critical velocity (CV) one week before the competition. Moreover, blood samples, anthropometric measurements and reported muscle soreness were obtained before, during and after ‘Brazil 135 Ultramarathon’. The volunteers completed the race in 46.6±3.1h, velocity average of 4.9±0.3km/h (34.5±1.9% of CV) and took 3.7±0.9h of pause time. Regarding inflammation and hematological responses, leukocytes, neutrophils, monocytes, C-reactive protein, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration and platelets increased whereas basophils decreased pre versus post-race (P<0.05). Moreover, post-race levels of leukocytes and neutrophils were correlated (P<0.05) to absolute running velocity (R=0.70; 0.76, respectively), running velocity relative to CV (%CV) (R=0.92; 0.96, respectively) and pause time (R= -0.66; -0.69, respectively). Concerning muscle damage and oxidative stress responses, creatine kinase, lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase and albumin levels as well as muscle soreness increased (P<0.05) while catalase, glutathione reductase (GR) activities and urate levels did not change (P>0.05) throughout the race. Muscle damage enzymes at 217-km were correlated (P<0.05) to running velocity (R=0.68 to 0.83) and pause time (R= -0.63 to -0.74) and muscle soreness at 177-km ... (Complete abstract click electronic access below)

Cheng, Yuk Lap. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 64-67). / Abstracts in English and Chinese; appendix and questionnaire also in Chinese. / ACKNOWLEDGEMENT --- p.I / ABSTRACT --- p.II / TABLE OF CONTENT --- p.V / LIST OF FIGURES --- p.VII / LIST OF TABLES --- p.VIII / Chapter I --- INTRODUCTION --- p.1 / Background --- p.1 / Statement of Problem --- p.3 / Hypothesis --- p.3 / Significance of Study --- p.4 / Theoretical Contribution --- p.4 / Practical Contribution --- p.4 / Operational Definition --- p.5 / Chapter II --- REVIEW OF LITERATURE --- p.7 / Problem of poor fitting --- p.7 / Common foot problem --- p.10 / Definition of fit --- p.11 / Recommendation of shoe fit --- p.13 / Sizing --- p.13 / Pressure distribution --- p.14 / Subjective fit --- p.15 / Footwear Comfort --- p.15 / Chapter III --- METHODOLOGY --- p.18 / Design --- p.18 / Subject --- p.18 / Instrumentation --- p.18 / Fit questionnaire --- p.18 / Foot scanner --- p.19 / Pressure sensors --- p.19 / Running shoes --- p.20 / Shoe lasts --- p.20 / Procedure --- p.21 / Foot scanning --- p.22 / Fit questionnaire --- p.24 / Set up --- p.24 / Reliability test --- p.25 / Pressure measurement --- p.25 / Data Reduction --- p.29 / Foot scanning --- p.29 / Fit questionnaire --- p.29 / Video --- p.29 / Pressure distribution --- p.30 / Data Analysis --- p.30 / Chapter IV --- RESULT --- p.32 / Subject Detail --- p.32 / Questionnaire --- p.32 / Fit Rating --- p.37 / Size Difference --- p.39 / Pressure Distribution --- p.43 / Regression --- p.46 / Chapter V --- DISCUSSION --- p.52 / Subjective fit rating --- p.52 / Reliability of the fit questionnaire --- p.52 / Fit rating --- p.53 / Size --- p.54 / Foot shape --- p.54 / Dimensional Difference --- p.54 / Correlation with subjective fit --- p.55 / Pressure --- p.58 / Dimensional Difference and Pressure --- p.59 / Subjective fit and objective measures --- p.60 / Limitation --- p.61 / Future Direction --- p.62 / Chapter VI --- CONCLUSION --- p.63 / Chapter VII --- REFERENCE --- p.64 / APPENDIX / Appendix A -Explanation of study --- p.68 / Appendix B - Informed consent --- p.69 / Appendix C - Footwear fit questionnaire --- p.70 / Appendix D -Explanations of fit questionnaire --- p.72 / Appendix E - Anthropometric information of the subjects --- p.73 / Appendix F - Fit rating --- p.74 / Appendix G - Foot dimensions of the subjects --- p.89 / Appendix H - Foot - last size difference of each subject --- p.90 / Appendix I - Guilford's suggested interpretation for value of r --- p.92

The purpose of this dissertation was to better understand position specific physical qualities and how they relate to high speed running performance throughout the course of a competitive collegiate soccer season. The amount of literature devoted to female soccer players is scarce when compared to the vast amount of literature associated with male soccer players. The objectives of this dissertation were: 1) to determine if playing position has an influence on physical qualities such as speed, change of direction ability, countermovement jump performance, relative strength, rate of force development, and intermittent endurance capacity, 2) investigate the differences between high and lower caliber players as defined by minutes played per match when considering the physical qualities mentioned previously, 3) and finally to assess the influence of physical qualities and playing position on high speed running performance throughout the course of a competitive season. Data from 57 Division I Women’s Collegiate soccer players from a single institution were used. The influence of playing position and caliber of play on physical qualities were assessed using both laboratory and field based testing assessments. It appears that attacking based players (forward, wide midfielder, and attacking midfielder) were faster compared to defensive based players (central defensive midfielder, central defender, and goalkeeper) when assessed during 20 m sprint assessments and change of direction ability assessments. The only variable to differentiate between caliber of play was the Yo-Yo Intermittent Recovery Test – Level 1 (YYIRT1), indicating that higher caliber players possess greater intermittent endurance capacity compared to lower caliber players. Playing position was the major contributor when assessing high speed running performance during competition, explaining almost 70% of the variance. These findings highlight the impact of tactical factors on physical performance during competition and the need for position based assessments to better identify relevant physical qualities with respect to playing position in Division I Women’s Collegiate Soccer players. Further research is needed with a wider range of players from various levels to determine if these findings exist across all levels or are unique to the institution used during these investigations.

The purpose of this study was to examine the independent effects of anterior knee pain (AKP) on bilateral ground reaction force (GRF) during running, with a focus on GRF applied to the uninvolved leg, which, prior to this study, had never been evaluated. Twelve volunteers completed three data collection sessions, that corresponded to one of three conditions (control, sham, and pain), in a counterbalanced order. For each session, subjects ran for five minutes. For the pain and sham sessions, respectively, hypertonic and isotonic saline were infused into the infrapatellar fat pad of the right leg during the running, while no infusion was involved in the control session. GRF data were collected during the final 30 seconds of running. Functional statistics were used to determine the effects of session and leg (right and left) on vertical and anterior-posterior GRF throughout the stance phase of running. A mixed model ANOVA was used to determine the effect of session and leg on vertical GRF load rate, impulse due to vertical, propulsive, and braking GRFs. A repeated measures ANOVA was used to determine the effect of session and time on subject-perceived pain. Alpha was set to 0.05 for all statistical comparisons. Unexpectedly, no significant session × leg interaction existed for vertical GRF at any time point during stance phase of running. Similarly, the experimental AKP did not affect impulse due to vertical GRF or load rate for the vertical GRF. There was, however, a significant session × leg interaction for anterior-posterior GRF. For the pain session, involved-leg braking GRF was 11% greater than uninvolved-leg braking GRF, during the first 9% of stance phase. There was also a significant between-session difference for involved-leg braking impulse (p = 0.023) and uninvolved-leg propulsive impulse (p = 0.027). The mean involved-leg braking impulses were 11.3 Ns (± 0.6), 13.2 Ns (± 0.6) and 13.2 Ns (± 0.6) for the pain, control, and sham sessions, respectively. Mean uninvolved-leg propulsive impulses were 14.8 Ns (± 1.3), 13.6 Ns (± 1.3), and 13.5 Ns (± 1.3) for the pain, control, and sham sessions, respectively. These differences in anterior-posterior GRF might reflect a compensatory unloading of the involved leg due to AKP.

Music appears to have advantageous effects during exercise as it has been shown to increase motivation, decrease ratings of perceived exertion (RPE), and improve exercise performance. The improvement of running performance in particular, is the main effect recreational runners want to focus on as many want to improve their time in road races. Running velocity, indicated by a faster time to completion is thought to improve with an increase in step frequency, step length, or a combination of these variables. Currently, there is limited research that observes methods to help increase step frequency or step length. The manipulation of music cadence may be considered an effective training method that influences step frequency. The purpose of this study was to observe the effect of music cadence on step frequency in the recreational runner. A total of 30 recreational runners (15 male, 15 female) with a mean age of 31.0 ± 5.8 (range= 20-39), a BMI of 24.0 ± 3.3 (range= 19-32), and an estimated VO2 max of 49.6 ± 5.4 (range= 41-60) participated in this study. Individually, runners completed four 1600-meter time trials on an outdoor track at maximal effort. The first trial was a familiarization trial where participants ran 1600 meters with no music. Two music conditions were then created for each runner based on their natural step frequency obtained during the familiarization trial. The first condition represented music at natural step cadence and the second condition represented music at increased step cadence. The next three 1600 meter time trials were randomized and included a control condition of no music, a natural cadence music condition at the runner's natural step frequency, and an increased cadence music condition of 10-20 beats per minute (bpm) above the natural cadence music condition. Results indicated that step frequency was significantly higher during the increased cadence music condition compared to both the natural cadence music and no music conditions (p < 0.05). Additionally, time to completion was significantly lower in the increased cadence music condition compared to both the natural cadence music and no music conditions (p < 0.05). Lastly, there was no significant difference in step length among music conditions. These results indicate that music cadence had a positive influence on running performance as it was able to increase step frequency and improve time to completion in a group of recreational runners. Therefore, for practical application, recreational runners can alter music cadence to help improve running performance.

It has been shown that a high level of aerobic fitness is important for athletes participating in intermittent (team) sports. The majority of studies investigating the effects of traditional and sport-specific aerobic interval exercise on physiological measures and performance have involved field-based team sports. In some instances the effectiveness of sport-specific aerobic training has been questioned. To date, no study has investigated the influence of a sport-specific training approach in the sport of basketball. Purpose: The aim of the present study was to evaluate the effectiveness of a basketball specific endurance circuit on improving measures of aerobic fitness. Methods: Ten male high school basketball players, age 16.4 ± 1.2 years, ranked by fitness level and randomly assigned to a training group (N = 6) or control group (N = 4) participated in the study. The sport-specific aerobic endurance training replaced the fitness component of regular training and was performed during the competitive season. The sport-specific training consisted of interval training using a basketball specific endurance circuit, four times 4 min at 90-95% HRpeak with a 3 min recovery at 60-70% HRpeak, twice per week for 6 weeks. During this time the control group performed regular basketball training. Results: For both the training and control groups the actual mean training intensity for total training duration were 77.4 ± 2.9% HRpeak and 74.1 ± 6.7% HRpeak, respectively. The actual mean training intensity during the work intervals in the training group was 84.1 ± 2.3% HRpeak. There were no clear differences between effects of the two training approaches for measures of maximal oxygen uptake (3.3%; 90% confidence limits, ± 19.3%), running economy (-3.3%; 90% confidence limits, ± 14.2%), repeated sprint ability (0.6%; 90% confidence limits, ± 5.7%) and anaerobic power maintenance during the repeated sprints (-13.7%; 90% confidence limits, ± 49.0%). However, a clear non-trivial effect on sub-maximal heart rate was observed (-7.3%; 90% confidence limits, ± 2.0%) suggesting a beneficial training effect after training. Some evidence for attenuation of speed (-1.8 to -2.8%; 90% confidence limits, ± 3.4 to 5.7%) and power (-1.7%; 90% confidence limits, ± 17.1%) was apparent. Conclusion: Although clear changes in sub-maximal HR responses were observed in the training group, the data in the present study suggests that a basketball specific endurance circuit has little effect on other laboratory and field-based measures of aerobic fitness. In fact, the basketball specific endurance circuit may lead to reduced improvements in jumping and sprinting performances. Further research is required to clarify the effect of aerobic training approaches on basketball-specific fitness and performance.

This autoethnographic study investigates the emotional and social dimensions of a coaching relationship from the athlete�s perspective. Autoethnography is an approach that draws on highly personalised biographical accounts in which authors tell stories about their lived experiences (Ellis & Bochner, 2000; Richardson, 2000) in order to place the "self within a social context" (Reed-Danahay, 1997, p. 9). Consequently, through the analysis of my memories and ethnographic notes, I analyse my experiences as an Olympic marathon runner and, in particular, the challenges I faced with my coach. In the process of investigating the emotional and social dimensions of the coaching process (which I have divided into three phases), I focus specifically on the creation of (1) my 'athletic identity', (2) the power relationship that developed between my coach and myself and, (3) my early retirement from running. In order to make sense of my experiences, I draw upon theories of identity (e.g. Bradley, 1996), Foucauldian concepts on 'power' (e.g. Foucault, 1980), and the literature addressing 'premature retirement' (e.g. Sparkes 1996; 2000). Finally, a conclusion summarises the main points made in addition to outlining their implications for further coaching research and practice.

The relationships between selected sprint specific bounding exercises and sprint performance were analysed using fourteen sprint athletes (7 elite performers, 7 sub-elite performers). Subjects were required to perform sprints over 60m, Counter Movement Jumps with and without loading (20kg), High Speed Alternate Leg Bounding over 30m and High Speed Single Leg Hopping over 20m. All athletes were subject to anthropometric measurement (Height, Weight and Leg Length). Of all variables measured, the Elite group were significantly better (p<0.001) in Counter Movement Jump, Time to 60m, Time from 30m to 60m and in their Maximal Running Velocity. Linear regressions were carried out on all variables that correlated with Time to 30m (Acceleration Phase) and Maximal Running Velocity at both the pO.OOl and p<0.01 level of significance. This allowed several prediction tables to be compiled that had performance measures (sprints and jumps) that could be used as testing measures for sprint athletes to determine their Acceleration Phase and Maximal Running Velocity. A stepwise multiple regression demonstrated that Time to 60m was the best predictor of Maximal Running Velocity. Time to 60m, Leg length, High Speed Alternate Leg Bounding and Sprint Stride Rate were the best predictors of the Acceleration Phase. A Stepwise cross-validation linear discriminant function analysis was used to determine the best predictors from both sprint and jump measures that would distinguish an athlete as an elite or sub-elite performer. From sprint variables, Time to 60m and Time to 30m were the two variables that best placed a sprint subject in either the Elite or Sub-elite group. From the bounding variables, Counter Movement Jump and the Ground Contact Time of the High Speed Alternate Leg Bounding were the two variables that best placed a sprint subject in either the Elite or Sub-elite group. The present study suggests that Time to 60m is the best predictor of Maximal Running Velocity and Acceleration Phase. Counter Movement Jumping and High speed Alternate Leg Bounding are also useful tools in developing and testing elite sprint athlete performance.

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