Thesis (M.S.)--Eastern Washington University, 2003. / Includes bibliographical references (leaves [57]-65).

Thesis (Ph. D.)--University of Northern Colorado, 2005. / Includes bibliographical references (leaves [148]-160) Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Thesis (Ph. D.)--University of Northern Colorado, 2005. / Includes bibliographical references (leaves [148]-160)

Muscle strength has been identified as an important contributor to athletic performance. Little attention however, has been paid to the specific relationship between peak isokinetic muscle strength and sprint starting performance. The aim of this study was to determine the influence of an adapted front knee angle, as determined by isokinetic assessment (the angle of peak torque production), on starting performance. Sixteen track sprinters, of elite-national or competitive-regional standard, were asked to perform eight sprints over 50m using four separate starting techniques. Technique 1 featured the athlete’s usual starting preferences while Techniques 2, 3 and 4 featured a standardised set of starting preferences with experimental modifications of the front knee angle in the “set” position. Isokinetic muscle strength was measured at slow (60°/s) and fast (240°/s) test speeds in order to determine the angle of peak torque production for concentric knee extension of each subject’s lead leg. Using one-way analysis of variance (ANOVA) and Post Hoc analysis (LSD), no significant differences (p>0.05) were observed between the experimental techniques for: block time, force-time measures during block time, sprint times, sprint velocity and acceleratio n measures at intervals up to 50m. Significant differences (p<0.05) were however observed between reaction times for the experimental techniques. Slower reaction times are most likely due to increased upper body pretension, resulting from the increased hip elevation seen for these techniques. The results indicate that increased hip elevation may have delayed the initiation of the relevant motor response required to affect an optimal sprint start. Technique 1 resulted in the shortest reaction times, shortest block times, fastest sprint times and greatest sprint velocities for all four techniques. This result was possibly due to the athlete’s experience with, and repeated use of, this technique. The experimental techniques therefore provided no added advantage over the subject’s preferred starting technique and did not significantly optimise sprint starting performance. The results show that modification of the front knee angle had no significant influence on sprint starting performance and sprint running ve locity or acceleration patterns up to 50m. Using Pearson’s Correlation Coefficient to determine the strongest correlations between isokinetic knee strength and sprint starting performance, analysis revealed that the strongest relationships were found between sprint starting performance expressed as acceleration and isokinetic knee strength expressed as relative peak torque and absolute peak torque. For Technique 1 the strongest correlation was found between acceleration (30m - 40m) and relative peak torque as measured at a test speed of 240°/s (r = 0.62). For the remaining experimental techniques, the strongest correlation was found between acceleration (10m - 20m) and relative peak torque as measured at a test speed of 60°/s (r = 0.53) for Technique 2, between acceleration (40m - 50m) and peak torque measured at a test speed of 60°/s (r = 0.72) for Technique 3, and between acceleration (0m - 5m) and peak torque as measured at a test speed of 240°/s (r = 0.71) for Technique 4. These results suggest that isokinetic muscle strength does not correlate strongly with sprint starting performance and that additional factors, such as neuromuscular organisation and muscle fibre typing, possibly make a greater contribution to optimal sprint starting performance.

The purposes of this study were to examine the (a) attentional focus strategies used by high school distance runners, (b) changes in attentional focus across four laps in three 1.6 km runs, and (c) effects of a pre-performance intervention using motivational and instructional self talk on the attentional focus strategies used by and performance of high school distance runners. Participants (N = 42) completed a background and demographic questionnaire, the Cross Country Attentional Focus Inventory (CCAFI), a motivational and instructional statement survey, and the Self-Motivation Inventory. A series of oneway ANOVAs revealed significant differences in the types of attentional strategies used by each group, as well as fluctuations in use of strategies. The experimental group associated more during the each of the 1.6 km trials, whereas the control group dissociated more throughout each trial. A significant group by week interaction was found, with the experimental group maintaining their performance and the control group slowing from week one to week three.

Orientador: Antonia Dalla Pria Bankoff / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Educação Fisica / Made available in DSpace on 2018-08-08T02:53:42Z (GMT). No. of bitstreams: 1 Schmidt_Ademir_D.pdf: 56451276 bytes, checksum: 5b096a2973998a3ce6ed8b83c8ddc707 (MD5) Previous issue date: 2006 / Resumo: As corridas de longa distância, sejam de caráter competitivo ou de promoção da saúde, geram cargas compressivas consideráveis no sistema locomotor. Essas cargas, se não adequadamente distribuídas, predispõem os praticantes a lesões crônicas e agudas. Nesse sentido, o objetivo desta pesquisa foi estudar a distribuição da pressão plantar e do equilíbrio corporal em corredores de longa distância. Participaram do estudo 17 corredores de longa distância do sexo masculino com idade X = 28,5 :t 9,5 anos, peso X = 63,6 :t 6,9 Kg e altura X = 173,5 :t 7,0 cm. A seleção dos sujeitos foi feita segundo critérios de acessibilidade. Para o estudo da distribuição da pressão plantar e do equiHbrio corporal, foi utilizado um baropodômetro eletrônico para realizar uma análise estática, dinâmica (andando e correndo) e uma análise estabilométrica. Os três testes foram realizados com os corredores inicialmente descalços e posteriormente utilizando seu tênis de corrida. Além da análise baropodométrica, os sujeitos responderam um questionário contendo 23 perguntas sobre sua rotina de treino, índice de lesões sofridas, distância percorrida semanalmente, dentre outras. Na análise estatística utilizou-se o teste paramétrico t-Student para grupos independentes. Os resultados da análise baropodométrica estática dos corredores demonstraram distribuição assimétrica da carga entre os membros inferiores, com maior carga direcionada para a parte anterior do pé direito. A distribuição da pressão plantar revelou maior carga na parte anterior do pé esquerdo nos testes dinâmicos com os corredores descalços, enquanto que nos testes com o calçado esportivo não foram detectadas diferenças significantes. Foi constatado que os corredores avaliados realizam o contato pé-solo predominantemente com a parte anterior do pé. O uso do calçado esportivo não apresentou nenhuma interferência específica nos testes realizados. A oscilação do centro de pressão foi maior nos testes monopodálicos. O estudo do equilíbrio corporal demonstrou significativa dependência do sistema visual e tendência de maior oscilação do centro de pressão no eixo X / Abstract: Long distance running as a competitive way or even to promote health produces considerable compressive load on the locomotor system. If this load is not properly distributed, it makes practitioners prone to chronic and acute injuries. Therefore, the purpose of this research was to study the plantar pressure distribution and body balance in long distance runners. In total 17 male long distance runners were considered for this study with age X = 28.5 :t 9.5, weight X = 63.6 :t 6.9 kg and height X = 173.5 :t 7.0 cm. The selection of individuaIs was done by following accessibility criteria. To perform the study ofthe plantar pressure distribution and body balance an electronic baropodometer was used. The baropodometric tests comprised a static, a dynamic (walking and running) and a stabilometric analysis. All tests were performed initially barefoot and afterwards with the runners wearing their running shoes. The individuaIs also responded to a 23 question survey about their practice routine, injury incidence, distance performed during the week and so forth. A parametric t-Student test for independent groups was used for the statistic analysis. The results of the static baropodometric analysis showed asymmetric pressure distribution between the lower extremities, with greater pressure directed to the right forefoot. The plantar pressure distribution reveled grater load directed to the left forefoot in the dynamic tests performed with the sport running shoes, meanwhile no significant differences were detected in the barefoot tests. The results also demonstrated that the runners evaluated in this study were predominantly forefoot strikers. The running shoes did not show any specific influence on the tests results. Oscillation of the center of pressure was greater in the unilateral tests. The body balance study revealed significant visual system dependence and a tendency of greater oscillations ofthe center ofpressure on the X-axis / Doutorado / Ciencia do Desporto / Doutor em Educação Física

No description available.

A survey research design was employed to explore the relationship between negative addiction to running and running commitment, through the construct of running enjoyment, amongst black, Zulu-speaking runners. Translated versions of the Biographical Information Questionnaire (Leask, 1997), Negative Addiction Scale (Hailey & Bailey, 1982), and Running Enjoyment Questionnaire (Basson & Macpherson, 1998) were administered to an opportunity sample of 79 Zulu-speaking runners, drawn from athletic clubs in the Durban and Pietermaritzburg regions of KwaZulu-Natal. On the basis of their negative addiction scale scores, runners were assigned to either a high (n = 23), moderate (n= 35), or low addiction group (n= 21). Multiple correlation analyses, parametric and nonparametric analysis of variance procedures, factor . analyses, and multiple regression procedures were used to examine the relationship between running dependence, the four sources of running enjoyment, and demographic variables. Significant relationships were found between running dependence and all four sources of running enjoyment. Further, the length of running history , the importance given to running by the participant, perceived fitness levels, and the number of Comrades marathons run were shown to play a role in both running dependence and commitment processes. For Zulu-speaking runners, both intrinsic and achievement running enjoyment sources were found to be more motivating than either extrinsic or nonachievement factors. Extrinsic and achievement factors were found to be more motivating for Zulu-speaking runners compared to Macpherson's (1998) sample of white runners. These results were discussed with reference to the literature on running dependence, running commitment, and cultural influences on motivation. / Thesis (M.Soc.Sc.)-University of Natal, Pietermaritzburg, 2000.

Lok Cheuk-ming, Andy. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 62-73). / Text in English; abstracts in English and Chinese. / Lok Cheuk-ming, Andy. / Acknowledgments --- p.i / Abstract --- p.iii / Table of Contents --- p.vi / List of Tables --- p.viii / List of Figures --- p.ix / Chapter CHAPTER1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Purpose --- p.4 / Chapter 1.3 --- Significance of Study --- p.4 / Chapter CHAPTER2 --- Review of Literature --- p.5 / Chapter 2.1 --- "Energy Metabolism During Prolonged, Submaximal Exercise" --- p.5 / Chapter 2.1.1 --- Energy Metabolism in Humans / Chapter 2.1.2 --- Amount of Energy Stores in Body / Chapter 2.1.3 --- Substrates Utilization during Prolonged Exercise / Chapter 2.2 --- Importance of Pre-exercise Nutrition on Exercise Performance --- p.9 / Chapter 2.2.1 --- Pre-exercise CHO Supplementation / Chapter 2.2.2 --- Timing of CHO and Transient Hypoglycemia / Chapter 2.2.3 --- Type of CHO / Chapter 2.2.4 --- Other Nutrients / Chapter 2.3 --- Application of the Glycemic Index to Pre-exercise Nutrition --- p.14 / Chapter 2.3.1 --- Definition of Glycemic Index (GI) / Chapter 2.3.2 --- Ingestion of GI Foods Before Exercise / Chapter 2.3.3 --- Summary of the Previous Findings / Chapter CHAPTER3 --- Methodology --- p.23 / Chapter 3.1 --- General Methods --- p.23 / Chapter 3.2 --- Participants --- p.34 / Chapter 3.3 --- Experimental Design --- p.34 / Chapter 3.4 --- Procedures --- p.37 / Chapter 3.5 --- Prescribed Glycemic Index Meals --- p.39 / Chapter 3.6 --- Analysis --- p.40 / Chapter 3.7 --- Statistical Analysis --- p.41 / Chapter CHAPTER4 --- Results --- p.42 / Chapter 4.1 --- Running Performance --- p.42 / Chapter 4.2 --- Dietary Analysis --- p.43 / Chapter 4.3 --- Physiological Changes At Rest and During Exercise --- p.44 / Chapter 4.5 --- Changes in Perceptual Variables and Heart Rates At Rest and During Exercise --- p.54 / Chapter CHAPTER5 --- Discussion --- p.56 / Recommendation and Applications --- p.61 / References --- p.62 / Appendices --- p.74

During extreme exercise, athletes experience increased inflammation that is similar to the acute phase response. Endurance athletes, distance runners in particular, are also more susceptible to compromised iron stores. This study evaluated inflammation, immune function and iron status in athletes completing a 50K ultramarathon. Twenty-two well-trained distance runners, 11 males and 11 females, were randomized in a double blind manner into--1) those who consumed 300 mg vitamin E and 1000 mg vitamin C (500 mg twice daily) or 2) placebos--for six weeks before and one week following a 50K ultramarathon race. Blood samples were obtained on 13 separate occasions throughout the study: before supplementation, during supplementation, the day before the race, pre-race, mid-race, immediately post-race, 2 hours following the race, and daily for six days following the race. Plasma levels of ascorbic acid and ��-tocopherol were measured by HPLC with electrochemical detection. Inflammatory cytokines, interleukin-6 (IL-6), tumor necrosis factor-�� (TNF-��), and interleukin-1�� (IL-1��) were measured using standard clinical assays. Each subject recorded immune function in an activity log and incidence of illness was tabulated as number of days ill. Ferritin was measured by enzyme immunoassay. Hemoglobin, hematocrit, and total-iron binding capacity (TIBC) and serum total iron were analyzed by standard procedures. Plasma concentrations of ascorbic acid and ��-tocopherol increased significantly in supplemented subjects (p<0.0001). Although the ultramarathon race elicited an inflammatory response, antioxidant supplementation did not alter the responses of IL-6 and TNF-��, which both increased from pre-race to mid-race, post- and post-2 h (Scheffe post-hoc analysis, p<0.0001) and returned to pre-race concentrations by 1 day after the race. Male supplemented subjects had lower IL-1�� concentrations compared to females consuming the supplement or to males consuming the placebo (ANCOVA, gender/time/treatment interaction; p<0.01) at mid-race (p<0.05 females, p<0.005 males), post 1 and 2 days (all p<0.002). Males had significantly higher ferritin levels than the female subjects (ANOVA, p<0.0001); supplementation resulted in lower ferritin concentrations at post-5 days (p<0.02, ANCOVA treatment time interaction, p<0.005). Supplementation did not reduce the days illness among those consuming antioxidants compared to those consuming the placebos. Ferritin not only increases during inflammation, it also is a measure of iron stores. Females had significantly lower levels of iron than the male subjects for each of the iron parameters measured (hemoglobin and hematocrit both p<0.0001, ferritin p<0.001, TIBC p<0.02) excluding serum total iron. The ferritin concentrations measured in the women were indicative of depleted iron stores (<12 ��g/l), and antioxidant supplementation increased hematocrit levels in the female subjects (p<0.05). This investigation indicates that female distance runners need to be aware of an increased susceptibility to iron depletion compared to their male counterparts. Antioxidant supplementation improved hematocrit levels (p<0.05) among female runners and may improve iron status among females with depleted stores. Although other investigations have suggested that antioxidant vitamins decrease exercise induced inflammation, no profound benefit of supplementation was found in this investigation though a response similar to the acute phase response was elicited by the ultramarathon race. Improvements in IL-i and ferritin in response to antioxidant supplementation may indicate that the supplementation was beneficial, but more research is needed to draw definitive conclusions. / Graduation date: 2003